APPENDIX 1 LITERATURE REVIEW
THE EFFECT OF SOIL AND WATER ON SLOPE STABILITY
Appendix 1 Content page
CONTENT PAGE
ABSTRACT I
CONTENT PAGE II
LIST OF FIGURES III
LIST OF TABLES IV
All INTRODUCTION 1
A12 SEDIMENT STRENGTH 2 Al21 Shear stress 3 Al22 Shear strength 3
Al22l Cohesive soils 4 Al222 Frictional Forces 4
Al23 Soil Types 6
Al3 THE EFFECT OF WATER ON SOIL STRENGTH 8 Al31 Types of slope failure 9 Al32 Adsorption by soils 10 Al33 Hydro-compaction of soils l2 A134 Liquefaction 13 A135 Mathematical modelling for slope failure J4
Al35l Application to shallow and deep landslides 17 AJ36 Problems associated with water models 18
Al4 CONCLUSION 19
REFERENCES 20
Investigation of land stability at Windermere Northern Tasmania II
Appendix l The effect of soil and water on slope stability
chapter AI THE EFFECT OF SOIL AND WATER ON SLOPE STABILITY
Alllntroduction
Characterisation of potential regions for slope failure is a complicated and often uncertain
process due to the great variety of slope morphologies slope geology (Gerrard 1992)
and the effect of water on soil moisture and soil properties Because of the complexity of
the slope erosion system large numbers of slope stability studies have been carried out
Norton and Smith (1930) were amongst the first to recognise an inverse relationship
between slope angles and the textural B-horizon and later identified a correlation between
slope and soil structure texture and consistency
Technological development has since included improved methods of identifying and
describing properties which influence land stability Three main factors influence slope
stability 1) gravity and therefore the gradient of the slope 2) troublesome earth materials
and the occurrence of triggering events and 3) water and the hydrologic characteristics of
middot the slope (Murch et al 1995) This chapter considers a number of models that have been
introduced to make correlations between soil characteristics and slope stability The
effects of water on sediment strength and of how such changes can be calculated in terms
of increasing the likelihood of failure are also described
The term soil in this paper is not restricted to the usual definition of the surface layer
Instead soil means particulate matter including clay silt sand or gravel (essentially
unconsolidated or lightly consolidated material without cement) Terminologies
associated with soil mechanics referred to in this paper are defined in table All
Investigation of land stability at Windermere Northern Tasmania
)
Appendix I The effect of soil and water on slope stability
Table All Tenninology discussed in text
Tenn Shear stress (t)
Shear stren th Angle of Internal friction ( ltP)
Cohesion (c)
Friction
Definition The gravitational force applied to a body of material that causes movement arallel to slo e The maximum resistance of soils to shear stress The angle between the normal and the contact surfaces of two bodies and the direction of the resultant reaction between them when a force is middotust tendin to cause relative slidin (Walker 1991) The mutual attraction that exists between fme grained particles tending to hold them together as a mass without the application of external forces
Clay which at no time in its history has been subject to pressure Normally consolidated cia s Over consolidated cia
middot middot middot~~~~~~r~e~ss~u~re~middot----------------~ history has been subject to pressure greater urden ressure
A12 Sediment strength
The nature and extent of forces acting on slopes and the extent of slope stability is
influenced by such inter-related variables as geology slope gradient climate vegetation
hydrological characteristics and time (Murch et al 1995) Although slopes often appear
stable and static they are in fact active parts of the dynamic evolving pattern of
landscape formation (Keller 1992) Slope stability is commonly expressed by equations
involving the critical shear stress required for movement and the angle of response
(Ulrich 1987) As illustrated in figure Al1 (Lowe 1966) steep slopes are generally
more prone to failure than flat slopes due to the topographically induced gravitational
shear strength Two opposing forces act on a body at rest on a slope shear stress and
shear strength (Murch et al 1995) In general steepening slope gradients reduce the
shear strength by changes in cohesion pore pressure and normal stress thus allowing the
body to move (Carson and Kirby 1972)
A121 Shear stress
The stress that controls changes in the volume and the strength of soil is known as the
effective stress When a load is applied to a saturated soil it will be carried by the water in
Investigation of land stability at Windermere Northem Tasmania 2
Appendix I The effect of soil and water on slope stability
the soil voids (causing an increase in pore water pressure) or by the soil skeleton in the
form of grain to grain contact (Smith 1971) Thus stress is a function of particle friction
and weight (mass x gravity)
DRIVING FORCES
RESISTING FORCES
Figure All The force acting on a typical sliding mass For equilibrium to be reached force such as Er and El must be equal P must equal and oppose the weight force (W) The tangential component T of the weight force W must resist the developed shear strength Sd Where lt1gt
is the angle of internal friction and i is the slope (Source Lowe 1966)
A122 Shear strength Shear strength is the internal resistance of soils to movement (Murch et al 1995)
Resistance to shear is made up of two parts particle friction and cohesion Frictional
resistance varies with the level of normal stress applied on the shear plane whereas
cohesive resistance is assumed to be independent of the applied stress ie it is a constant
value (Smith 1971) The strength envelope of a soil can be expressed by the Mohrshy
coulomb equation
t = c + cr tanltgt equation 1
t is the shear stress at failure cr is the normal stress on the shear plane c the cohesion and
lt1gt is the angle of internal friction (Bryant 1993) This equation states that shear stress will
equal cohesion when no normal stress is acting on the shear plane If shear strength
Investigation of land stability at Windermere Northern Tasmania 3
)
)
Appendix 1 The effect of soil and water on slope stability
exceeds shear stress movement will not occur If failure has occurred previously the
shear strength will be reduced resulting in residual strength not peak strength
A1221 Cohesive soils
Cohesive soils exhibit inter-particle attraction and possess inherent strength due to surface
tension of capillary water Most cohesive soils contain about 10 or more of clay
particles (Hail 1977) Differences between the properties of cohesive clays and non-
cohesive soils ( lt 10 clay) are outlined in Table Al2 The level of compaction of
cohesive soils is important because slightly compressed soils (normally consolidated) have
a high water content
In contrast highly compressed clays (over-consolidated clays) have much lower water
carrying capacities The compaction process gives stability to materials on slopes (Bryant
1993) The friction angle for cohesionless soils increases by 6 to 8 deg from loose to dense
particle arrangements (Bell 1992) Differences between clays in these two states are often
paralleled by being present with non-cohesive soils in their loose and dense states
respectively (Keller 1992) The sediment strength of cohesive soils figure Al3 is much
less then that of gravel and sand soils due to Vander Waal-type bonding (Bryant 1993)
Therefore the angle at which the sediment are stable is much lower This angle is known as
the angle of response (Murch et al 1995)
A1222 Frictional Forces
Frictional forces resist shear stress and contribute to sediment strength through the
interaction of individual grains within the sediments (Montgomery 1997) Frictional
resistance is a function of density size and shape of sediment particles combined with the
level of particle compaction (Keller 1992) Since most soils are mixtures of coarse and
fine-grained particles soil strength is usually the result of both cohesion and internal
friction
Investigation of land stability at Windermere Northern Tasmania 4
middotmiddot-----middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot-~-middotmiddot----~--middotmiddotmiddotmiddotmiddotmiddotmiddot------
~ ppendix 1 The effect of soil and water on sl~le stability
Table Alll Selected engineering properties of soils
Soil Qassilication Strength Permeability Angle of Cohesion Volume changes Liquid Plasticity Maximo General Use As internal (c) function of limit limit m slope Construction friction (ell) (kNmz) activity angle Material
Gravels well-graded gravel very high high 34 35 - very small - - 10- 15 excellent poorly graded gravel high very high - - - good silty gravel high low - - - good clayey gravel high- very low - 35-50 - good
medium Sands well-graded sand very high high 32-42 - small - - 7 excellent
poorly graded sand high high - - - fair silty sand high low - - - fair clayey sand high- very low lt75 lt35 - good
medium Silts silt medium low 32-36 75 24-35 14-25 5 fair
micaceous silt medium- low poor low
organic silt low low fair Qay silty clay medium very low 150-75 lt35 Low good-fair
high plastic clay low very low 300- 150 high 70-90 Very high 5 poor organic clay low very low 35-50 Intermedi poor
ate
Source Keller 1992 Smith 1968 Mitchell 1976 Smith 1968
Investigation of land stability at Windermere Northern Tasmania 5
Appendix 1 The effect of soil and water on slope stability
A 123 Soil Types In general each soil type exhibits different properties and can be divided into four main
groupings according to structure and composition (1) gravels (2) silts (3) sands and (4)
clays (see figure A12)
Coarse grained granular soils and to some degree sands lack cohesion and rely on densely
packed interlocking grains to create frictional resistance at the grain contacts This results
in a large 4gt value when compared to clay rich soils thus giving high strength The
presence of water in the voids of granular soil does not usually produce significant
changes in the value of internal friction However if pressures develop in the pore water
there may be changes in the effective stresses between particles and shear strength may be
reduced If the pore water can readily drain from the soil mass during the application of
stress granular material behaves as it does when dry
Young (1972) noted that the friction angle for pure clay is as low as 5deg but increases with
the inclusion of coarser grained particles Soils composed primarily of gravels may be
stable at angles as great as 15deg providing the matrix is not made up of clay Even the
largest friction angle for clay minerals is much less than those for cohesionless soils which
are generally in the range of 10 to 15 degrees (Mitchell 1976) Consolidated rocks have
much greater friction angles eg sandstone gt21deg
However the mineral and particle size distribution in itself is only part of the equation As
shown in figure A 12 other essential properties are the liquid limit and the plastic
(Atterberg) limit In general the greater the quantities of clay minerals in soil the higher
the plasticity and the greater the potential for shrinkage and swell The lower the porosity
the higher the compressibility the higher the cohesion and the lower the angle of internal
friction These properties are exhibited primarily because water is strongly attracted to
clay mineral surfaces and promotes plasticity whereas the non-clay minerals have little
affmity for water and do not develop significant plasticity even in a fine grained form It is
probable therefore that most soil water is associated with the clay phase (Smith 1971 )
Investigation of land stability at Windermere Northern Tasmania 6
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
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z~
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t4
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 1 Content page
CONTENT PAGE
ABSTRACT I
CONTENT PAGE II
LIST OF FIGURES III
LIST OF TABLES IV
All INTRODUCTION 1
A12 SEDIMENT STRENGTH 2 Al21 Shear stress 3 Al22 Shear strength 3
Al22l Cohesive soils 4 Al222 Frictional Forces 4
Al23 Soil Types 6
Al3 THE EFFECT OF WATER ON SOIL STRENGTH 8 Al31 Types of slope failure 9 Al32 Adsorption by soils 10 Al33 Hydro-compaction of soils l2 A134 Liquefaction 13 A135 Mathematical modelling for slope failure J4
Al35l Application to shallow and deep landslides 17 AJ36 Problems associated with water models 18
Al4 CONCLUSION 19
REFERENCES 20
Investigation of land stability at Windermere Northern Tasmania II
Appendix l The effect of soil and water on slope stability
chapter AI THE EFFECT OF SOIL AND WATER ON SLOPE STABILITY
Alllntroduction
Characterisation of potential regions for slope failure is a complicated and often uncertain
process due to the great variety of slope morphologies slope geology (Gerrard 1992)
and the effect of water on soil moisture and soil properties Because of the complexity of
the slope erosion system large numbers of slope stability studies have been carried out
Norton and Smith (1930) were amongst the first to recognise an inverse relationship
between slope angles and the textural B-horizon and later identified a correlation between
slope and soil structure texture and consistency
Technological development has since included improved methods of identifying and
describing properties which influence land stability Three main factors influence slope
stability 1) gravity and therefore the gradient of the slope 2) troublesome earth materials
and the occurrence of triggering events and 3) water and the hydrologic characteristics of
middot the slope (Murch et al 1995) This chapter considers a number of models that have been
introduced to make correlations between soil characteristics and slope stability The
effects of water on sediment strength and of how such changes can be calculated in terms
of increasing the likelihood of failure are also described
The term soil in this paper is not restricted to the usual definition of the surface layer
Instead soil means particulate matter including clay silt sand or gravel (essentially
unconsolidated or lightly consolidated material without cement) Terminologies
associated with soil mechanics referred to in this paper are defined in table All
Investigation of land stability at Windermere Northern Tasmania
)
Appendix I The effect of soil and water on slope stability
Table All Tenninology discussed in text
Tenn Shear stress (t)
Shear stren th Angle of Internal friction ( ltP)
Cohesion (c)
Friction
Definition The gravitational force applied to a body of material that causes movement arallel to slo e The maximum resistance of soils to shear stress The angle between the normal and the contact surfaces of two bodies and the direction of the resultant reaction between them when a force is middotust tendin to cause relative slidin (Walker 1991) The mutual attraction that exists between fme grained particles tending to hold them together as a mass without the application of external forces
Clay which at no time in its history has been subject to pressure Normally consolidated cia s Over consolidated cia
middot middot middot~~~~~~r~e~ss~u~re~middot----------------~ history has been subject to pressure greater urden ressure
A12 Sediment strength
The nature and extent of forces acting on slopes and the extent of slope stability is
influenced by such inter-related variables as geology slope gradient climate vegetation
hydrological characteristics and time (Murch et al 1995) Although slopes often appear
stable and static they are in fact active parts of the dynamic evolving pattern of
landscape formation (Keller 1992) Slope stability is commonly expressed by equations
involving the critical shear stress required for movement and the angle of response
(Ulrich 1987) As illustrated in figure Al1 (Lowe 1966) steep slopes are generally
more prone to failure than flat slopes due to the topographically induced gravitational
shear strength Two opposing forces act on a body at rest on a slope shear stress and
shear strength (Murch et al 1995) In general steepening slope gradients reduce the
shear strength by changes in cohesion pore pressure and normal stress thus allowing the
body to move (Carson and Kirby 1972)
A121 Shear stress
The stress that controls changes in the volume and the strength of soil is known as the
effective stress When a load is applied to a saturated soil it will be carried by the water in
Investigation of land stability at Windermere Northem Tasmania 2
Appendix I The effect of soil and water on slope stability
the soil voids (causing an increase in pore water pressure) or by the soil skeleton in the
form of grain to grain contact (Smith 1971) Thus stress is a function of particle friction
and weight (mass x gravity)
DRIVING FORCES
RESISTING FORCES
Figure All The force acting on a typical sliding mass For equilibrium to be reached force such as Er and El must be equal P must equal and oppose the weight force (W) The tangential component T of the weight force W must resist the developed shear strength Sd Where lt1gt
is the angle of internal friction and i is the slope (Source Lowe 1966)
A122 Shear strength Shear strength is the internal resistance of soils to movement (Murch et al 1995)
Resistance to shear is made up of two parts particle friction and cohesion Frictional
resistance varies with the level of normal stress applied on the shear plane whereas
cohesive resistance is assumed to be independent of the applied stress ie it is a constant
value (Smith 1971) The strength envelope of a soil can be expressed by the Mohrshy
coulomb equation
t = c + cr tanltgt equation 1
t is the shear stress at failure cr is the normal stress on the shear plane c the cohesion and
lt1gt is the angle of internal friction (Bryant 1993) This equation states that shear stress will
equal cohesion when no normal stress is acting on the shear plane If shear strength
Investigation of land stability at Windermere Northern Tasmania 3
)
)
Appendix 1 The effect of soil and water on slope stability
exceeds shear stress movement will not occur If failure has occurred previously the
shear strength will be reduced resulting in residual strength not peak strength
A1221 Cohesive soils
Cohesive soils exhibit inter-particle attraction and possess inherent strength due to surface
tension of capillary water Most cohesive soils contain about 10 or more of clay
particles (Hail 1977) Differences between the properties of cohesive clays and non-
cohesive soils ( lt 10 clay) are outlined in Table Al2 The level of compaction of
cohesive soils is important because slightly compressed soils (normally consolidated) have
a high water content
In contrast highly compressed clays (over-consolidated clays) have much lower water
carrying capacities The compaction process gives stability to materials on slopes (Bryant
1993) The friction angle for cohesionless soils increases by 6 to 8 deg from loose to dense
particle arrangements (Bell 1992) Differences between clays in these two states are often
paralleled by being present with non-cohesive soils in their loose and dense states
respectively (Keller 1992) The sediment strength of cohesive soils figure Al3 is much
less then that of gravel and sand soils due to Vander Waal-type bonding (Bryant 1993)
Therefore the angle at which the sediment are stable is much lower This angle is known as
the angle of response (Murch et al 1995)
A1222 Frictional Forces
Frictional forces resist shear stress and contribute to sediment strength through the
interaction of individual grains within the sediments (Montgomery 1997) Frictional
resistance is a function of density size and shape of sediment particles combined with the
level of particle compaction (Keller 1992) Since most soils are mixtures of coarse and
fine-grained particles soil strength is usually the result of both cohesion and internal
friction
Investigation of land stability at Windermere Northern Tasmania 4
middotmiddot-----middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot-~-middotmiddot----~--middotmiddotmiddotmiddotmiddotmiddotmiddot------
~ ppendix 1 The effect of soil and water on sl~le stability
Table Alll Selected engineering properties of soils
Soil Qassilication Strength Permeability Angle of Cohesion Volume changes Liquid Plasticity Maximo General Use As internal (c) function of limit limit m slope Construction friction (ell) (kNmz) activity angle Material
Gravels well-graded gravel very high high 34 35 - very small - - 10- 15 excellent poorly graded gravel high very high - - - good silty gravel high low - - - good clayey gravel high- very low - 35-50 - good
medium Sands well-graded sand very high high 32-42 - small - - 7 excellent
poorly graded sand high high - - - fair silty sand high low - - - fair clayey sand high- very low lt75 lt35 - good
medium Silts silt medium low 32-36 75 24-35 14-25 5 fair
micaceous silt medium- low poor low
organic silt low low fair Qay silty clay medium very low 150-75 lt35 Low good-fair
high plastic clay low very low 300- 150 high 70-90 Very high 5 poor organic clay low very low 35-50 Intermedi poor
ate
Source Keller 1992 Smith 1968 Mitchell 1976 Smith 1968
Investigation of land stability at Windermere Northern Tasmania 5
Appendix 1 The effect of soil and water on slope stability
A 123 Soil Types In general each soil type exhibits different properties and can be divided into four main
groupings according to structure and composition (1) gravels (2) silts (3) sands and (4)
clays (see figure A12)
Coarse grained granular soils and to some degree sands lack cohesion and rely on densely
packed interlocking grains to create frictional resistance at the grain contacts This results
in a large 4gt value when compared to clay rich soils thus giving high strength The
presence of water in the voids of granular soil does not usually produce significant
changes in the value of internal friction However if pressures develop in the pore water
there may be changes in the effective stresses between particles and shear strength may be
reduced If the pore water can readily drain from the soil mass during the application of
stress granular material behaves as it does when dry
Young (1972) noted that the friction angle for pure clay is as low as 5deg but increases with
the inclusion of coarser grained particles Soils composed primarily of gravels may be
stable at angles as great as 15deg providing the matrix is not made up of clay Even the
largest friction angle for clay minerals is much less than those for cohesionless soils which
are generally in the range of 10 to 15 degrees (Mitchell 1976) Consolidated rocks have
much greater friction angles eg sandstone gt21deg
However the mineral and particle size distribution in itself is only part of the equation As
shown in figure A 12 other essential properties are the liquid limit and the plastic
(Atterberg) limit In general the greater the quantities of clay minerals in soil the higher
the plasticity and the greater the potential for shrinkage and swell The lower the porosity
the higher the compressibility the higher the cohesion and the lower the angle of internal
friction These properties are exhibited primarily because water is strongly attracted to
clay mineral surfaces and promotes plasticity whereas the non-clay minerals have little
affmity for water and do not develop significant plasticity even in a fine grained form It is
probable therefore that most soil water is associated with the clay phase (Smith 1971 )
Investigation of land stability at Windermere Northern Tasmania 6
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
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~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
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11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix l The effect of soil and water on slope stability
chapter AI THE EFFECT OF SOIL AND WATER ON SLOPE STABILITY
Alllntroduction
Characterisation of potential regions for slope failure is a complicated and often uncertain
process due to the great variety of slope morphologies slope geology (Gerrard 1992)
and the effect of water on soil moisture and soil properties Because of the complexity of
the slope erosion system large numbers of slope stability studies have been carried out
Norton and Smith (1930) were amongst the first to recognise an inverse relationship
between slope angles and the textural B-horizon and later identified a correlation between
slope and soil structure texture and consistency
Technological development has since included improved methods of identifying and
describing properties which influence land stability Three main factors influence slope
stability 1) gravity and therefore the gradient of the slope 2) troublesome earth materials
and the occurrence of triggering events and 3) water and the hydrologic characteristics of
middot the slope (Murch et al 1995) This chapter considers a number of models that have been
introduced to make correlations between soil characteristics and slope stability The
effects of water on sediment strength and of how such changes can be calculated in terms
of increasing the likelihood of failure are also described
The term soil in this paper is not restricted to the usual definition of the surface layer
Instead soil means particulate matter including clay silt sand or gravel (essentially
unconsolidated or lightly consolidated material without cement) Terminologies
associated with soil mechanics referred to in this paper are defined in table All
Investigation of land stability at Windermere Northern Tasmania
)
Appendix I The effect of soil and water on slope stability
Table All Tenninology discussed in text
Tenn Shear stress (t)
Shear stren th Angle of Internal friction ( ltP)
Cohesion (c)
Friction
Definition The gravitational force applied to a body of material that causes movement arallel to slo e The maximum resistance of soils to shear stress The angle between the normal and the contact surfaces of two bodies and the direction of the resultant reaction between them when a force is middotust tendin to cause relative slidin (Walker 1991) The mutual attraction that exists between fme grained particles tending to hold them together as a mass without the application of external forces
Clay which at no time in its history has been subject to pressure Normally consolidated cia s Over consolidated cia
middot middot middot~~~~~~r~e~ss~u~re~middot----------------~ history has been subject to pressure greater urden ressure
A12 Sediment strength
The nature and extent of forces acting on slopes and the extent of slope stability is
influenced by such inter-related variables as geology slope gradient climate vegetation
hydrological characteristics and time (Murch et al 1995) Although slopes often appear
stable and static they are in fact active parts of the dynamic evolving pattern of
landscape formation (Keller 1992) Slope stability is commonly expressed by equations
involving the critical shear stress required for movement and the angle of response
(Ulrich 1987) As illustrated in figure Al1 (Lowe 1966) steep slopes are generally
more prone to failure than flat slopes due to the topographically induced gravitational
shear strength Two opposing forces act on a body at rest on a slope shear stress and
shear strength (Murch et al 1995) In general steepening slope gradients reduce the
shear strength by changes in cohesion pore pressure and normal stress thus allowing the
body to move (Carson and Kirby 1972)
A121 Shear stress
The stress that controls changes in the volume and the strength of soil is known as the
effective stress When a load is applied to a saturated soil it will be carried by the water in
Investigation of land stability at Windermere Northem Tasmania 2
Appendix I The effect of soil and water on slope stability
the soil voids (causing an increase in pore water pressure) or by the soil skeleton in the
form of grain to grain contact (Smith 1971) Thus stress is a function of particle friction
and weight (mass x gravity)
DRIVING FORCES
RESISTING FORCES
Figure All The force acting on a typical sliding mass For equilibrium to be reached force such as Er and El must be equal P must equal and oppose the weight force (W) The tangential component T of the weight force W must resist the developed shear strength Sd Where lt1gt
is the angle of internal friction and i is the slope (Source Lowe 1966)
A122 Shear strength Shear strength is the internal resistance of soils to movement (Murch et al 1995)
Resistance to shear is made up of two parts particle friction and cohesion Frictional
resistance varies with the level of normal stress applied on the shear plane whereas
cohesive resistance is assumed to be independent of the applied stress ie it is a constant
value (Smith 1971) The strength envelope of a soil can be expressed by the Mohrshy
coulomb equation
t = c + cr tanltgt equation 1
t is the shear stress at failure cr is the normal stress on the shear plane c the cohesion and
lt1gt is the angle of internal friction (Bryant 1993) This equation states that shear stress will
equal cohesion when no normal stress is acting on the shear plane If shear strength
Investigation of land stability at Windermere Northern Tasmania 3
)
)
Appendix 1 The effect of soil and water on slope stability
exceeds shear stress movement will not occur If failure has occurred previously the
shear strength will be reduced resulting in residual strength not peak strength
A1221 Cohesive soils
Cohesive soils exhibit inter-particle attraction and possess inherent strength due to surface
tension of capillary water Most cohesive soils contain about 10 or more of clay
particles (Hail 1977) Differences between the properties of cohesive clays and non-
cohesive soils ( lt 10 clay) are outlined in Table Al2 The level of compaction of
cohesive soils is important because slightly compressed soils (normally consolidated) have
a high water content
In contrast highly compressed clays (over-consolidated clays) have much lower water
carrying capacities The compaction process gives stability to materials on slopes (Bryant
1993) The friction angle for cohesionless soils increases by 6 to 8 deg from loose to dense
particle arrangements (Bell 1992) Differences between clays in these two states are often
paralleled by being present with non-cohesive soils in their loose and dense states
respectively (Keller 1992) The sediment strength of cohesive soils figure Al3 is much
less then that of gravel and sand soils due to Vander Waal-type bonding (Bryant 1993)
Therefore the angle at which the sediment are stable is much lower This angle is known as
the angle of response (Murch et al 1995)
A1222 Frictional Forces
Frictional forces resist shear stress and contribute to sediment strength through the
interaction of individual grains within the sediments (Montgomery 1997) Frictional
resistance is a function of density size and shape of sediment particles combined with the
level of particle compaction (Keller 1992) Since most soils are mixtures of coarse and
fine-grained particles soil strength is usually the result of both cohesion and internal
friction
Investigation of land stability at Windermere Northern Tasmania 4
middotmiddot-----middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot-~-middotmiddot----~--middotmiddotmiddotmiddotmiddotmiddotmiddot------
~ ppendix 1 The effect of soil and water on sl~le stability
Table Alll Selected engineering properties of soils
Soil Qassilication Strength Permeability Angle of Cohesion Volume changes Liquid Plasticity Maximo General Use As internal (c) function of limit limit m slope Construction friction (ell) (kNmz) activity angle Material
Gravels well-graded gravel very high high 34 35 - very small - - 10- 15 excellent poorly graded gravel high very high - - - good silty gravel high low - - - good clayey gravel high- very low - 35-50 - good
medium Sands well-graded sand very high high 32-42 - small - - 7 excellent
poorly graded sand high high - - - fair silty sand high low - - - fair clayey sand high- very low lt75 lt35 - good
medium Silts silt medium low 32-36 75 24-35 14-25 5 fair
micaceous silt medium- low poor low
organic silt low low fair Qay silty clay medium very low 150-75 lt35 Low good-fair
high plastic clay low very low 300- 150 high 70-90 Very high 5 poor organic clay low very low 35-50 Intermedi poor
ate
Source Keller 1992 Smith 1968 Mitchell 1976 Smith 1968
Investigation of land stability at Windermere Northern Tasmania 5
Appendix 1 The effect of soil and water on slope stability
A 123 Soil Types In general each soil type exhibits different properties and can be divided into four main
groupings according to structure and composition (1) gravels (2) silts (3) sands and (4)
clays (see figure A12)
Coarse grained granular soils and to some degree sands lack cohesion and rely on densely
packed interlocking grains to create frictional resistance at the grain contacts This results
in a large 4gt value when compared to clay rich soils thus giving high strength The
presence of water in the voids of granular soil does not usually produce significant
changes in the value of internal friction However if pressures develop in the pore water
there may be changes in the effective stresses between particles and shear strength may be
reduced If the pore water can readily drain from the soil mass during the application of
stress granular material behaves as it does when dry
Young (1972) noted that the friction angle for pure clay is as low as 5deg but increases with
the inclusion of coarser grained particles Soils composed primarily of gravels may be
stable at angles as great as 15deg providing the matrix is not made up of clay Even the
largest friction angle for clay minerals is much less than those for cohesionless soils which
are generally in the range of 10 to 15 degrees (Mitchell 1976) Consolidated rocks have
much greater friction angles eg sandstone gt21deg
However the mineral and particle size distribution in itself is only part of the equation As
shown in figure A 12 other essential properties are the liquid limit and the plastic
(Atterberg) limit In general the greater the quantities of clay minerals in soil the higher
the plasticity and the greater the potential for shrinkage and swell The lower the porosity
the higher the compressibility the higher the cohesion and the lower the angle of internal
friction These properties are exhibited primarily because water is strongly attracted to
clay mineral surfaces and promotes plasticity whereas the non-clay minerals have little
affmity for water and do not develop significant plasticity even in a fine grained form It is
probable therefore that most soil water is associated with the clay phase (Smith 1971 )
Investigation of land stability at Windermere Northern Tasmania 6
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
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I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
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J)
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1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
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fih
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
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0
~
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~ ~
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
)
Appendix I The effect of soil and water on slope stability
Table All Tenninology discussed in text
Tenn Shear stress (t)
Shear stren th Angle of Internal friction ( ltP)
Cohesion (c)
Friction
Definition The gravitational force applied to a body of material that causes movement arallel to slo e The maximum resistance of soils to shear stress The angle between the normal and the contact surfaces of two bodies and the direction of the resultant reaction between them when a force is middotust tendin to cause relative slidin (Walker 1991) The mutual attraction that exists between fme grained particles tending to hold them together as a mass without the application of external forces
Clay which at no time in its history has been subject to pressure Normally consolidated cia s Over consolidated cia
middot middot middot~~~~~~r~e~ss~u~re~middot----------------~ history has been subject to pressure greater urden ressure
A12 Sediment strength
The nature and extent of forces acting on slopes and the extent of slope stability is
influenced by such inter-related variables as geology slope gradient climate vegetation
hydrological characteristics and time (Murch et al 1995) Although slopes often appear
stable and static they are in fact active parts of the dynamic evolving pattern of
landscape formation (Keller 1992) Slope stability is commonly expressed by equations
involving the critical shear stress required for movement and the angle of response
(Ulrich 1987) As illustrated in figure Al1 (Lowe 1966) steep slopes are generally
more prone to failure than flat slopes due to the topographically induced gravitational
shear strength Two opposing forces act on a body at rest on a slope shear stress and
shear strength (Murch et al 1995) In general steepening slope gradients reduce the
shear strength by changes in cohesion pore pressure and normal stress thus allowing the
body to move (Carson and Kirby 1972)
A121 Shear stress
The stress that controls changes in the volume and the strength of soil is known as the
effective stress When a load is applied to a saturated soil it will be carried by the water in
Investigation of land stability at Windermere Northem Tasmania 2
Appendix I The effect of soil and water on slope stability
the soil voids (causing an increase in pore water pressure) or by the soil skeleton in the
form of grain to grain contact (Smith 1971) Thus stress is a function of particle friction
and weight (mass x gravity)
DRIVING FORCES
RESISTING FORCES
Figure All The force acting on a typical sliding mass For equilibrium to be reached force such as Er and El must be equal P must equal and oppose the weight force (W) The tangential component T of the weight force W must resist the developed shear strength Sd Where lt1gt
is the angle of internal friction and i is the slope (Source Lowe 1966)
A122 Shear strength Shear strength is the internal resistance of soils to movement (Murch et al 1995)
Resistance to shear is made up of two parts particle friction and cohesion Frictional
resistance varies with the level of normal stress applied on the shear plane whereas
cohesive resistance is assumed to be independent of the applied stress ie it is a constant
value (Smith 1971) The strength envelope of a soil can be expressed by the Mohrshy
coulomb equation
t = c + cr tanltgt equation 1
t is the shear stress at failure cr is the normal stress on the shear plane c the cohesion and
lt1gt is the angle of internal friction (Bryant 1993) This equation states that shear stress will
equal cohesion when no normal stress is acting on the shear plane If shear strength
Investigation of land stability at Windermere Northern Tasmania 3
)
)
Appendix 1 The effect of soil and water on slope stability
exceeds shear stress movement will not occur If failure has occurred previously the
shear strength will be reduced resulting in residual strength not peak strength
A1221 Cohesive soils
Cohesive soils exhibit inter-particle attraction and possess inherent strength due to surface
tension of capillary water Most cohesive soils contain about 10 or more of clay
particles (Hail 1977) Differences between the properties of cohesive clays and non-
cohesive soils ( lt 10 clay) are outlined in Table Al2 The level of compaction of
cohesive soils is important because slightly compressed soils (normally consolidated) have
a high water content
In contrast highly compressed clays (over-consolidated clays) have much lower water
carrying capacities The compaction process gives stability to materials on slopes (Bryant
1993) The friction angle for cohesionless soils increases by 6 to 8 deg from loose to dense
particle arrangements (Bell 1992) Differences between clays in these two states are often
paralleled by being present with non-cohesive soils in their loose and dense states
respectively (Keller 1992) The sediment strength of cohesive soils figure Al3 is much
less then that of gravel and sand soils due to Vander Waal-type bonding (Bryant 1993)
Therefore the angle at which the sediment are stable is much lower This angle is known as
the angle of response (Murch et al 1995)
A1222 Frictional Forces
Frictional forces resist shear stress and contribute to sediment strength through the
interaction of individual grains within the sediments (Montgomery 1997) Frictional
resistance is a function of density size and shape of sediment particles combined with the
level of particle compaction (Keller 1992) Since most soils are mixtures of coarse and
fine-grained particles soil strength is usually the result of both cohesion and internal
friction
Investigation of land stability at Windermere Northern Tasmania 4
middotmiddot-----middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot-~-middotmiddot----~--middotmiddotmiddotmiddotmiddotmiddotmiddot------
~ ppendix 1 The effect of soil and water on sl~le stability
Table Alll Selected engineering properties of soils
Soil Qassilication Strength Permeability Angle of Cohesion Volume changes Liquid Plasticity Maximo General Use As internal (c) function of limit limit m slope Construction friction (ell) (kNmz) activity angle Material
Gravels well-graded gravel very high high 34 35 - very small - - 10- 15 excellent poorly graded gravel high very high - - - good silty gravel high low - - - good clayey gravel high- very low - 35-50 - good
medium Sands well-graded sand very high high 32-42 - small - - 7 excellent
poorly graded sand high high - - - fair silty sand high low - - - fair clayey sand high- very low lt75 lt35 - good
medium Silts silt medium low 32-36 75 24-35 14-25 5 fair
micaceous silt medium- low poor low
organic silt low low fair Qay silty clay medium very low 150-75 lt35 Low good-fair
high plastic clay low very low 300- 150 high 70-90 Very high 5 poor organic clay low very low 35-50 Intermedi poor
ate
Source Keller 1992 Smith 1968 Mitchell 1976 Smith 1968
Investigation of land stability at Windermere Northern Tasmania 5
Appendix 1 The effect of soil and water on slope stability
A 123 Soil Types In general each soil type exhibits different properties and can be divided into four main
groupings according to structure and composition (1) gravels (2) silts (3) sands and (4)
clays (see figure A12)
Coarse grained granular soils and to some degree sands lack cohesion and rely on densely
packed interlocking grains to create frictional resistance at the grain contacts This results
in a large 4gt value when compared to clay rich soils thus giving high strength The
presence of water in the voids of granular soil does not usually produce significant
changes in the value of internal friction However if pressures develop in the pore water
there may be changes in the effective stresses between particles and shear strength may be
reduced If the pore water can readily drain from the soil mass during the application of
stress granular material behaves as it does when dry
Young (1972) noted that the friction angle for pure clay is as low as 5deg but increases with
the inclusion of coarser grained particles Soils composed primarily of gravels may be
stable at angles as great as 15deg providing the matrix is not made up of clay Even the
largest friction angle for clay minerals is much less than those for cohesionless soils which
are generally in the range of 10 to 15 degrees (Mitchell 1976) Consolidated rocks have
much greater friction angles eg sandstone gt21deg
However the mineral and particle size distribution in itself is only part of the equation As
shown in figure A 12 other essential properties are the liquid limit and the plastic
(Atterberg) limit In general the greater the quantities of clay minerals in soil the higher
the plasticity and the greater the potential for shrinkage and swell The lower the porosity
the higher the compressibility the higher the cohesion and the lower the angle of internal
friction These properties are exhibited primarily because water is strongly attracted to
clay mineral surfaces and promotes plasticity whereas the non-clay minerals have little
affmity for water and do not develop significant plasticity even in a fine grained form It is
probable therefore that most soil water is associated with the clay phase (Smith 1971 )
Investigation of land stability at Windermere Northern Tasmania 6
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
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~
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0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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bullbullbull bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
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bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
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it-
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix I The effect of soil and water on slope stability
the soil voids (causing an increase in pore water pressure) or by the soil skeleton in the
form of grain to grain contact (Smith 1971) Thus stress is a function of particle friction
and weight (mass x gravity)
DRIVING FORCES
RESISTING FORCES
Figure All The force acting on a typical sliding mass For equilibrium to be reached force such as Er and El must be equal P must equal and oppose the weight force (W) The tangential component T of the weight force W must resist the developed shear strength Sd Where lt1gt
is the angle of internal friction and i is the slope (Source Lowe 1966)
A122 Shear strength Shear strength is the internal resistance of soils to movement (Murch et al 1995)
Resistance to shear is made up of two parts particle friction and cohesion Frictional
resistance varies with the level of normal stress applied on the shear plane whereas
cohesive resistance is assumed to be independent of the applied stress ie it is a constant
value (Smith 1971) The strength envelope of a soil can be expressed by the Mohrshy
coulomb equation
t = c + cr tanltgt equation 1
t is the shear stress at failure cr is the normal stress on the shear plane c the cohesion and
lt1gt is the angle of internal friction (Bryant 1993) This equation states that shear stress will
equal cohesion when no normal stress is acting on the shear plane If shear strength
Investigation of land stability at Windermere Northern Tasmania 3
)
)
Appendix 1 The effect of soil and water on slope stability
exceeds shear stress movement will not occur If failure has occurred previously the
shear strength will be reduced resulting in residual strength not peak strength
A1221 Cohesive soils
Cohesive soils exhibit inter-particle attraction and possess inherent strength due to surface
tension of capillary water Most cohesive soils contain about 10 or more of clay
particles (Hail 1977) Differences between the properties of cohesive clays and non-
cohesive soils ( lt 10 clay) are outlined in Table Al2 The level of compaction of
cohesive soils is important because slightly compressed soils (normally consolidated) have
a high water content
In contrast highly compressed clays (over-consolidated clays) have much lower water
carrying capacities The compaction process gives stability to materials on slopes (Bryant
1993) The friction angle for cohesionless soils increases by 6 to 8 deg from loose to dense
particle arrangements (Bell 1992) Differences between clays in these two states are often
paralleled by being present with non-cohesive soils in their loose and dense states
respectively (Keller 1992) The sediment strength of cohesive soils figure Al3 is much
less then that of gravel and sand soils due to Vander Waal-type bonding (Bryant 1993)
Therefore the angle at which the sediment are stable is much lower This angle is known as
the angle of response (Murch et al 1995)
A1222 Frictional Forces
Frictional forces resist shear stress and contribute to sediment strength through the
interaction of individual grains within the sediments (Montgomery 1997) Frictional
resistance is a function of density size and shape of sediment particles combined with the
level of particle compaction (Keller 1992) Since most soils are mixtures of coarse and
fine-grained particles soil strength is usually the result of both cohesion and internal
friction
Investigation of land stability at Windermere Northern Tasmania 4
middotmiddot-----middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot-~-middotmiddot----~--middotmiddotmiddotmiddotmiddotmiddotmiddot------
~ ppendix 1 The effect of soil and water on sl~le stability
Table Alll Selected engineering properties of soils
Soil Qassilication Strength Permeability Angle of Cohesion Volume changes Liquid Plasticity Maximo General Use As internal (c) function of limit limit m slope Construction friction (ell) (kNmz) activity angle Material
Gravels well-graded gravel very high high 34 35 - very small - - 10- 15 excellent poorly graded gravel high very high - - - good silty gravel high low - - - good clayey gravel high- very low - 35-50 - good
medium Sands well-graded sand very high high 32-42 - small - - 7 excellent
poorly graded sand high high - - - fair silty sand high low - - - fair clayey sand high- very low lt75 lt35 - good
medium Silts silt medium low 32-36 75 24-35 14-25 5 fair
micaceous silt medium- low poor low
organic silt low low fair Qay silty clay medium very low 150-75 lt35 Low good-fair
high plastic clay low very low 300- 150 high 70-90 Very high 5 poor organic clay low very low 35-50 Intermedi poor
ate
Source Keller 1992 Smith 1968 Mitchell 1976 Smith 1968
Investigation of land stability at Windermere Northern Tasmania 5
Appendix 1 The effect of soil and water on slope stability
A 123 Soil Types In general each soil type exhibits different properties and can be divided into four main
groupings according to structure and composition (1) gravels (2) silts (3) sands and (4)
clays (see figure A12)
Coarse grained granular soils and to some degree sands lack cohesion and rely on densely
packed interlocking grains to create frictional resistance at the grain contacts This results
in a large 4gt value when compared to clay rich soils thus giving high strength The
presence of water in the voids of granular soil does not usually produce significant
changes in the value of internal friction However if pressures develop in the pore water
there may be changes in the effective stresses between particles and shear strength may be
reduced If the pore water can readily drain from the soil mass during the application of
stress granular material behaves as it does when dry
Young (1972) noted that the friction angle for pure clay is as low as 5deg but increases with
the inclusion of coarser grained particles Soils composed primarily of gravels may be
stable at angles as great as 15deg providing the matrix is not made up of clay Even the
largest friction angle for clay minerals is much less than those for cohesionless soils which
are generally in the range of 10 to 15 degrees (Mitchell 1976) Consolidated rocks have
much greater friction angles eg sandstone gt21deg
However the mineral and particle size distribution in itself is only part of the equation As
shown in figure A 12 other essential properties are the liquid limit and the plastic
(Atterberg) limit In general the greater the quantities of clay minerals in soil the higher
the plasticity and the greater the potential for shrinkage and swell The lower the porosity
the higher the compressibility the higher the cohesion and the lower the angle of internal
friction These properties are exhibited primarily because water is strongly attracted to
clay mineral surfaces and promotes plasticity whereas the non-clay minerals have little
affmity for water and do not develop significant plasticity even in a fine grained form It is
probable therefore that most soil water is associated with the clay phase (Smith 1971 )
Investigation of land stability at Windermere Northern Tasmania 6
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
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~
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0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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bullbullbull bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
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bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
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it-
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
)
)
Appendix 1 The effect of soil and water on slope stability
exceeds shear stress movement will not occur If failure has occurred previously the
shear strength will be reduced resulting in residual strength not peak strength
A1221 Cohesive soils
Cohesive soils exhibit inter-particle attraction and possess inherent strength due to surface
tension of capillary water Most cohesive soils contain about 10 or more of clay
particles (Hail 1977) Differences between the properties of cohesive clays and non-
cohesive soils ( lt 10 clay) are outlined in Table Al2 The level of compaction of
cohesive soils is important because slightly compressed soils (normally consolidated) have
a high water content
In contrast highly compressed clays (over-consolidated clays) have much lower water
carrying capacities The compaction process gives stability to materials on slopes (Bryant
1993) The friction angle for cohesionless soils increases by 6 to 8 deg from loose to dense
particle arrangements (Bell 1992) Differences between clays in these two states are often
paralleled by being present with non-cohesive soils in their loose and dense states
respectively (Keller 1992) The sediment strength of cohesive soils figure Al3 is much
less then that of gravel and sand soils due to Vander Waal-type bonding (Bryant 1993)
Therefore the angle at which the sediment are stable is much lower This angle is known as
the angle of response (Murch et al 1995)
A1222 Frictional Forces
Frictional forces resist shear stress and contribute to sediment strength through the
interaction of individual grains within the sediments (Montgomery 1997) Frictional
resistance is a function of density size and shape of sediment particles combined with the
level of particle compaction (Keller 1992) Since most soils are mixtures of coarse and
fine-grained particles soil strength is usually the result of both cohesion and internal
friction
Investigation of land stability at Windermere Northern Tasmania 4
middotmiddot-----middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot-~-middotmiddot----~--middotmiddotmiddotmiddotmiddotmiddotmiddot------
~ ppendix 1 The effect of soil and water on sl~le stability
Table Alll Selected engineering properties of soils
Soil Qassilication Strength Permeability Angle of Cohesion Volume changes Liquid Plasticity Maximo General Use As internal (c) function of limit limit m slope Construction friction (ell) (kNmz) activity angle Material
Gravels well-graded gravel very high high 34 35 - very small - - 10- 15 excellent poorly graded gravel high very high - - - good silty gravel high low - - - good clayey gravel high- very low - 35-50 - good
medium Sands well-graded sand very high high 32-42 - small - - 7 excellent
poorly graded sand high high - - - fair silty sand high low - - - fair clayey sand high- very low lt75 lt35 - good
medium Silts silt medium low 32-36 75 24-35 14-25 5 fair
micaceous silt medium- low poor low
organic silt low low fair Qay silty clay medium very low 150-75 lt35 Low good-fair
high plastic clay low very low 300- 150 high 70-90 Very high 5 poor organic clay low very low 35-50 Intermedi poor
ate
Source Keller 1992 Smith 1968 Mitchell 1976 Smith 1968
Investigation of land stability at Windermere Northern Tasmania 5
Appendix 1 The effect of soil and water on slope stability
A 123 Soil Types In general each soil type exhibits different properties and can be divided into four main
groupings according to structure and composition (1) gravels (2) silts (3) sands and (4)
clays (see figure A12)
Coarse grained granular soils and to some degree sands lack cohesion and rely on densely
packed interlocking grains to create frictional resistance at the grain contacts This results
in a large 4gt value when compared to clay rich soils thus giving high strength The
presence of water in the voids of granular soil does not usually produce significant
changes in the value of internal friction However if pressures develop in the pore water
there may be changes in the effective stresses between particles and shear strength may be
reduced If the pore water can readily drain from the soil mass during the application of
stress granular material behaves as it does when dry
Young (1972) noted that the friction angle for pure clay is as low as 5deg but increases with
the inclusion of coarser grained particles Soils composed primarily of gravels may be
stable at angles as great as 15deg providing the matrix is not made up of clay Even the
largest friction angle for clay minerals is much less than those for cohesionless soils which
are generally in the range of 10 to 15 degrees (Mitchell 1976) Consolidated rocks have
much greater friction angles eg sandstone gt21deg
However the mineral and particle size distribution in itself is only part of the equation As
shown in figure A 12 other essential properties are the liquid limit and the plastic
(Atterberg) limit In general the greater the quantities of clay minerals in soil the higher
the plasticity and the greater the potential for shrinkage and swell The lower the porosity
the higher the compressibility the higher the cohesion and the lower the angle of internal
friction These properties are exhibited primarily because water is strongly attracted to
clay mineral surfaces and promotes plasticity whereas the non-clay minerals have little
affmity for water and do not develop significant plasticity even in a fine grained form It is
probable therefore that most soil water is associated with the clay phase (Smith 1971 )
Investigation of land stability at Windermere Northern Tasmania 6
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
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~
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0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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bullbullbull bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
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bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
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it-
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
middotmiddot-----middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot-~-middotmiddot----~--middotmiddotmiddotmiddotmiddotmiddotmiddot------
~ ppendix 1 The effect of soil and water on sl~le stability
Table Alll Selected engineering properties of soils
Soil Qassilication Strength Permeability Angle of Cohesion Volume changes Liquid Plasticity Maximo General Use As internal (c) function of limit limit m slope Construction friction (ell) (kNmz) activity angle Material
Gravels well-graded gravel very high high 34 35 - very small - - 10- 15 excellent poorly graded gravel high very high - - - good silty gravel high low - - - good clayey gravel high- very low - 35-50 - good
medium Sands well-graded sand very high high 32-42 - small - - 7 excellent
poorly graded sand high high - - - fair silty sand high low - - - fair clayey sand high- very low lt75 lt35 - good
medium Silts silt medium low 32-36 75 24-35 14-25 5 fair
micaceous silt medium- low poor low
organic silt low low fair Qay silty clay medium very low 150-75 lt35 Low good-fair
high plastic clay low very low 300- 150 high 70-90 Very high 5 poor organic clay low very low 35-50 Intermedi poor
ate
Source Keller 1992 Smith 1968 Mitchell 1976 Smith 1968
Investigation of land stability at Windermere Northern Tasmania 5
Appendix 1 The effect of soil and water on slope stability
A 123 Soil Types In general each soil type exhibits different properties and can be divided into four main
groupings according to structure and composition (1) gravels (2) silts (3) sands and (4)
clays (see figure A12)
Coarse grained granular soils and to some degree sands lack cohesion and rely on densely
packed interlocking grains to create frictional resistance at the grain contacts This results
in a large 4gt value when compared to clay rich soils thus giving high strength The
presence of water in the voids of granular soil does not usually produce significant
changes in the value of internal friction However if pressures develop in the pore water
there may be changes in the effective stresses between particles and shear strength may be
reduced If the pore water can readily drain from the soil mass during the application of
stress granular material behaves as it does when dry
Young (1972) noted that the friction angle for pure clay is as low as 5deg but increases with
the inclusion of coarser grained particles Soils composed primarily of gravels may be
stable at angles as great as 15deg providing the matrix is not made up of clay Even the
largest friction angle for clay minerals is much less than those for cohesionless soils which
are generally in the range of 10 to 15 degrees (Mitchell 1976) Consolidated rocks have
much greater friction angles eg sandstone gt21deg
However the mineral and particle size distribution in itself is only part of the equation As
shown in figure A 12 other essential properties are the liquid limit and the plastic
(Atterberg) limit In general the greater the quantities of clay minerals in soil the higher
the plasticity and the greater the potential for shrinkage and swell The lower the porosity
the higher the compressibility the higher the cohesion and the lower the angle of internal
friction These properties are exhibited primarily because water is strongly attracted to
clay mineral surfaces and promotes plasticity whereas the non-clay minerals have little
affmity for water and do not develop significant plasticity even in a fine grained form It is
probable therefore that most soil water is associated with the clay phase (Smith 1971 )
Investigation of land stability at Windermere Northern Tasmania 6
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
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J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
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~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
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0
~
~
~ ~
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 1 The effect of soil and water on slope stability
A 123 Soil Types In general each soil type exhibits different properties and can be divided into four main
groupings according to structure and composition (1) gravels (2) silts (3) sands and (4)
clays (see figure A12)
Coarse grained granular soils and to some degree sands lack cohesion and rely on densely
packed interlocking grains to create frictional resistance at the grain contacts This results
in a large 4gt value when compared to clay rich soils thus giving high strength The
presence of water in the voids of granular soil does not usually produce significant
changes in the value of internal friction However if pressures develop in the pore water
there may be changes in the effective stresses between particles and shear strength may be
reduced If the pore water can readily drain from the soil mass during the application of
stress granular material behaves as it does when dry
Young (1972) noted that the friction angle for pure clay is as low as 5deg but increases with
the inclusion of coarser grained particles Soils composed primarily of gravels may be
stable at angles as great as 15deg providing the matrix is not made up of clay Even the
largest friction angle for clay minerals is much less than those for cohesionless soils which
are generally in the range of 10 to 15 degrees (Mitchell 1976) Consolidated rocks have
much greater friction angles eg sandstone gt21deg
However the mineral and particle size distribution in itself is only part of the equation As
shown in figure A 12 other essential properties are the liquid limit and the plastic
(Atterberg) limit In general the greater the quantities of clay minerals in soil the higher
the plasticity and the greater the potential for shrinkage and swell The lower the porosity
the higher the compressibility the higher the cohesion and the lower the angle of internal
friction These properties are exhibited primarily because water is strongly attracted to
clay mineral surfaces and promotes plasticity whereas the non-clay minerals have little
affmity for water and do not develop significant plasticity even in a fine grained form It is
probable therefore that most soil water is associated with the clay phase (Smith 1971 )
Investigation of land stability at Windermere Northern Tasmania 6
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
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=
(1
t4
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t4 ~
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
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Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
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) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
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Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
)
)
Appendix 1 The effect of soil and water on slope stability
The liquid limit is the moisture content of a soil above which it behaves as a fluid and
below which it behaves as a plastic The Atterberg limit defines the plastic limit of clay
below which at the shrinkage limit it becomes fragmented and crumbly The characteristic
positions of organic inorganic silts and clays with reference to the level of activity (A
line) figure AL2 have been well established (Mitchell 1976) Activity is a measure of soil
susceptibility to changes in exchangeable cations and pore fluid composition
0 70
60
50
11 40 middotu middot 30
20
10
0
10 20
Inorganic Clays of Low
Plasticity
Inorganic Silts of Low Com-
pressibilitv
Cohesion less Soils
10
Lw =30
Liquid Limit Lw
40 50 so 70
Liquid Limit
Inorganic Clays of High
Plasticity
Inorganic Silts of High Compressibility
and Organic Clays
Inorganic Silts of Medium Compressibility
and Organic Silts
Figure A12 Atterberg Plasticity Chart (Source Mitchell 1976)
Investigation of land stability at Windermere Northern Tasmania
100
7
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
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~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
)
Appendix 1 The effect of soil and water on slope stability
Al3 The effect of water on soil strength
Water is present in most rocks and sediments near the Earths surface and strongly
influences the effective stress states of soils (Iverson amp Major 1987) Soil strength is
generally reduced by water content and can result in slope instability (figure Al3)
Marshall et al ( 1996) proposed that cohesion is weakened as water content is adsorbed
into the soil structure However increasing the water content changes the load and the
gravity COfiponent may be more important
200 Suction 1500 500 30kPa
CIS 160 f f ~
~ ~
c -120 eo s
IU -U) 80 IU -middot-U)
s 40 IU
0 0 004 008 012
Water content g g- 1
Figure A13 Effects of water content on the cohesive strength of soil (source Marshall et al 1996)
The addition of small quantities of water to dry (unsaturated) soils increases adhesion and
the soils become plastic due to the presence of moisture films between grains
(Montgomery 1997) Thus shear strength due to chemical bonding (Van der Waals
bonds) is greater than shear stress In contrast the saturation of soils decreases shear
strength due to particles losing contact because of increases in pore pressure (Keller
1992 Terlien 1997) and hence loss of sediment strength Slope failure may also occur
under self-weight if sediments are saturated
Investigation of land stability at Windennere Northern Tasmania 8
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
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Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
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IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix l The effect of soil and water on slope stability
Table Al3 Descriptions for movement types
Classification Description
Fall A is a mass which is detached from a steep slope or cliff and descends to a lower surface The moving mass travels mostly through the air by free falling (Eckel 1958)
Topple The block rotates forward about a pivot point under the action of gravity without collapsing Movement is generally rapid
Slide Consists of shear strain and displacement along one or more surfaces Movement results from failure along one or more failure planes
Lateral spread Lateral extension accommodated by shear or tensile fracturing The failure can involve elements of rotation translation and flow Movement generally starts suddenly and proceeds rapidly Telfer 1988)
Flow Flow has the appearance of a body which behaves as a fluid when the force caused by water is significantly large any deformable material will flow Movement is generally rapid with gravity as the primary reason for movement
A132 Adsorption by soils
A substantial amount of movement is associated with the expansion and contraction of
soils as the result of adsorption (Young 1972) Adsorption in this context is the process
of taking up water at the surface of soil particles thereby changing their effective volumes
Such volume changes are caused by chemical attraction and addition of water layers into
the chemical structure of sediments (Keller 1992) This process is particularly common in
clay rich sediment where water molecules are inserted between submicroscopic clay plates
that have high plasticity indices as illustrated in figure AL5 (Murch et al 1995) Sediment
expansion due to water drastically reduces the shear strength of soils and often
contributes to slope movement
Investigation of land stability at Windermere Northern Tasmania 10
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
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~
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0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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bullbullbull bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
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bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
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it-
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix I The effect of soil and water on slope stability
ltcan de ay
ay elate
--- --- --- ---A iater ciecules
Figure AlS Diagram illustrating the expansive nature of clays (Murch et al
1995)
Thomas in 1928 demonstrated that the type of clay mineral was also an influencing factor
(in Marshall et al 1996) Montmorillonite is the most expansive clay mineral due to its
expanding crystal lattice which adsorbs more water at a given value of ee0 expanding by
as much as 15 times its original volume (Keller 1992) In contrast kaolinite has relatively
large crystals and thus a smaller surface area available for adsorption Illite has similar
crystal dimensions to montmorillinite but does not exhibit the expanding lattice and has
been categorised between montmorillinite and kaolinite in terms of adsorption potential
(Marshall et al 1996) The bonds between the adjacent silicate layers of illite are affected
by the potassium ions thus resulting in greater strength and tighter packing (Smith 1971)
These effects of clay properties on adsorption are illustrated in figure A16
The transition from open to compact arrangements causes a sudden loss in residual shear
strength montmorillonite has the lowest value ( ltgtR = 5) illite ( ltgtR = 1 0) and kaolinite the
highest value (ltgtR = 15) (Walker amp Fell 1987) The values for ltgtRare generally related to
particle shape and inter-particle bonding hence the ltgtR angle decreases with increasing
liquid limits However not all clays have plate like structures amorphous clay minerals
have granular structures which lead to much higher residual friction angles commonly
greater than 25 a (Walker amp Fell 1987)
Investigation of land stability at Windermere Nonhem Tasmania II
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
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~II
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Ix)~lJo( bullbull~
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0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
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Aa
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~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
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~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
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~ ~
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
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Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 1 The effect of soil and water on slope stability
lIne potenlill ItJ It- or MPI
02S -28 -1~4 -~9 -30 ~
010
1l ~
015 ~ ~ 010 ~
005
Kaolinite o
O~ 04 06 08 10 Rel~lie ~pour pressure e(r
Figure A16 Adsorption of water vapour by different clays (Source Marshal et aI
1996)
A133 Hydro-compaction of soils
A decrease in the volume of expansive clays (drying out) is referred to as hydroshy
compaction This occurs when water is removed from the soil structure leaving behind a
porous medium At low water contents ionic hydration can be a strong force which tends
to separate particles (Graham 1964) Defmite cracks are formed in the soil during the
contracting phase (Barlow amp Newton 1975) In general the swelling and shrinkage
properties of clay minerals follow the same pattern as their plasticity properties The more
plastic the mineral the greater the potential for swell and shrinkage
The obvious mechanism for this process is the presence of expanding clays under the
influence of seasonal inequalities in rainfall Each time expansion takes place the soil tends
to be pushed outwards at right angles to the slope and the soil mass is weakened On
shrinkage the soil settles back into its original state but tends to be moved down slope by
gravity Creep rates are generally proportional to the sine of the angle of the slope
(Graham 1964) It has been suggested however that expansion and contraction does not
always occur normal to the slope because up slope movements have been noted in
practical experiments Such changes in water content change the load of the soil on a
slope saturated soil by weight alone may cause slope failure due to the increase of shear
stress
Investigation of land stability at Windermere Northern Tasmania 12
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
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Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
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IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 1 The effect of soil and water on slope stability
When a layer of soil is loaded some of the pore water is expelled from its voids moving
away from the region of high stress (hydrostatic gradients are created by the load)
Terzaghi (1943) showed a relationship between the unit load and the void ratio for a
sediment by plotting the void ratio e against the logarithm of the unit load p (Bell
1992) The shape of the resultant curve indicates the stress history of the sediment The
curve is linear for normally consolidated clays and curved for over-consolidated clays
Over-consolidated clays are considerably less compressible than normally consolidated
clays
Al~4 Liquefaction~
~t The transformation of sediments from solid to liquid state is called liquefaction (Murch et
aI 1995) The point at which transition takes place from a solid to a liquid state is called
the liquid limit and is dependent on sediment characteristics as illustrated in figure AI7
Materials with high liquid limits such as clay remain plastic over a broad range of water
content The strength or shear resistance of the soil at the base of a slide is largely
determined by the angle of slope down which sliding may occur (Hail 1977)
Hutchinson (1968) noted that loss of shear strength due to high water-soil ratios leads
mass transport not mass movement because the soil particles are contained within stream
flow and not in contact with other soil particles As sediment concentrations increase
progressively from a viscose to a plastic flow the liquidity index falls well below the liquid
limit
The process of soil liquefaction results in changes to granular soil assemblages due to the
j disturbance of the internal structure of soil by water By converting the soil into a flowing
fluid mass there is no minimum angle for flow (Murch et al 1995) Liquefaction results in
sediments flowing rather than sliding along a failure surface (Iverson amp Major 1996)
Static liquefaction conditions are expressed as z = cos [(A + lt1raquo + (8 - lt1raquo] = 1 Hydraulic
gradients greater than 2 are generally required to cause liquefaction which cannot take
place if water does not move towards the surface (Iverson amp Major 1986)
Investigation of land stability at Windermere Northern Tasmania J
13
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
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=
(1
t4
gt
~ gt
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t4 ~
0
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~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix I The effect of soil and water on slope stability
~
0
~
0 gt
Hard I Friable Plastic liquid
] = 1] sectl~ El Imiddot2 2C E-II c en I
I
o o~ 04 06 08 Water content I I-I
Figure Al7 Consistency state and shrinkage stage of remoulding soil illustrated by values appropriate to soil high in clay content (Source Marshall et al 1996)
)
Al35 Mathematical modelling for slope failure
Various analytical techniques exist for assessing slope stability The reliability and quantity
of the soil data knowledge of the slope geology and the consequence of failure (Walker amp
Fell 1987) should always govern selection of particular method for analysis Analytical
results are usually presented in the form of safety factors where the safety factor is the
relationship between the ratio of shear resistance to shear force (Young 1972) Examples
of the most widely used methods for predicting slope failures and assessing risk are
outlined in table Al4
Two principal methods are used to measure the shearing resistance of soils (a) direct
shear tests and (b) the triaxial test The triaxial test is the most common means of
obtaining the shear strength parameters c and lt1gt (Walker amp Fell 1987) It involves
subjecting a cylindrical soil sample contained within a rubber membrane to an axial load
while confined laterally by water or air at a pressure (cr3) The load is increased until the
soil fails at an axial stress (cri) (Marshall et al 1996) Illustrated in figure A18 when
equilibrium is reached a Mohr circle can be drawn through the two points (Habibi 1983)
Investigation of land stability at Windermere Northern Tasmania )
14
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
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Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
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IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix I The effect of soil and water on slope stability
The envelope of Mohrs circles is the curve which in soils is the Coulombs line defmed
by Huorslevs Law for cohesive soils t =c + (On - u) tanltgt in cohesionless soils this
curve is rectilinear
Table 14 Types of stability analysis
Types of analysis Formulae and remarks
Method of slices FELLENIUS METHOD (curved slip surface) Fs =Lcb seca + tancjgt (W cos amiddot u) I L W sin a
Where W is the mass and a the inclination of the base of any vertical slice u is pore pressure Remark Assumes soils are saturated only applies to circular slip surfaces as being the only cause of failure pore pressure is not considered Reference Yong amp Selig 1982 Walker amp Fell 1987
Circular slip method BISHOPS SIMPLIFIED METHOD Fs =LUcb + W (l-r) tancjgt1 (lm)1 LW sina
Where u is the pore pressure Remark Only applies to circular slip surfaces uses average pore water Reference Yong amp Selig 1982 Habib 1983
Non-circular slip JANBUS SIMPLIFIED METHOD surface Fs =fLU b c + (W - ub) tancjgt] (lcos anI L W tan a
Where f is a function of the curvature of the slip surface and the type of soil Remark Only applicable to slip surfaces of arbitrary shape Reference Telfer 1988
Homogenous TAYLOR~S METHOD Fs =L (cl) I L (W sina)
Remark Restricted to clays Reference Telfer 1988
Infinite slope analysis Fs =c + Z cos 2 ~ (Y-DlY) tancjgt1 fz sin~ cos~
Where z is the depth of slide ~ is the limited inclination f unit weight of soil fm unit weight of water Remark An extremely simple model The effective cohesion is less than ten it is assumed to be zero Ground water is taken to be parallel to the ground Reference Hail 1977 Walker amp Fell 1987
Investigation of land stability at Windermere Northern Tasmania 15
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
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=
(1
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t4 ~
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix I The effect of soil and water on slope stability
Envelope
~ lt III III QI-III L gt 0~ gt - 0- r = LJQI 2t
III
A ~ 11 0- 1 a C Normal Effective Stress a ~
Figure Al8 Method of obtaining the failure envelop from measurements by
triaxial compression (Source Walker amp Fell 1987)
Studies by Henkel and Skempton (1955) and Skempton (1964) appeared to demonstrate
the accuracy of the infInite slope method where a slide is long compared with its depth
(Hail 1976) However more recent works (eg Hutchinson 1967 and Hail 1976) suggest
that fIeld and laboratory correlations by Skempton were fortuitous because pore water
pressure must be measured at the surface using piezometers With tips carefully located on
the base of the slide and not estimated from observations of the level of standing water
borings Furthermore the rings shear apparatus (Bishop et al 1971) is thought to provide
lower residual strength measurements than would be obtained from limited displacement
of direct shear apparatus The triaxial compression method (Marshall et aI 1996) is a
more accurate technique
Accurate and reliable predictions of stability cannot always be made on the basis of
) limiting equilibrium studies The concept of limit equilibrium is not fundamental to
phenomena concerning stability but is only a device for determining the safety factors for
a soil or rock mass The state of critical or limiting equilibrium should not be confused
with the concept of limiting equilibrium
Al3Sl Application to shallow and deep landslides
Reid (1994) found a direct correlation between brief periods of rainfall and shallow
landslides Deeper landslides were triggered by prolonged rainfall (gt 200mm in 25 days)
Investigation of land stability at Windermere Northern Tasmania J
16
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
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location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
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bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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DIAMOND DRILLCORE LOG project hole no location page of logged by date
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
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description
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
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Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
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Figure A72 illustrates the soil classification according to the shear strength of
sediments
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Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix I The effect of soil and water on slope stability
this was later supported by Terlien (1997) Reid (1994) also noted that large rainstorms
induced a wide range of slope movements such as creep and solifuction movements that
do not require inclined slopes for movement (Kirkby 1967 Reid 1994) According to the
principal of effective stress landsliding may occur in response to locally elevated pore
pressure along the failure surface Prior to Terliens investigation such links between
rainfall and landsliding were based upon statistical correlations or empirically fitted models )
which were limited by available data
In the case of deep landslides on slopes possessing appreciable cohesion there is no single
angle of stability but a height angle relation as in the upper curve of figure A18 In
general for a given geology and climatic conditions surface landslides occur on gentler
slopes than deep landslides (Terlien 1997) Two explanations have been proposed for the
lower limiting angles for surface landslides (1) the observed limiting angle for clayshy
dominated soils this generally corresponds with stability conditions calculated by using
the residual shear strength (2) The relationship of deep slides to peak strength
(Hutchinson 1967) unless a deep failure had occurred previously However this
explanation does not apply to soils that are made up of large portions of sand gravel or
stones These soil types exhibit only small differences between peak and residual shearing
strength Equation 9 (from the infmite stability model) can be applied to shallow slides
provided that the angle of the failure plane is approximately equal to the slope of the
ground surface
During the early to mid 1980s quantitative analytical processes were introduced to study
the role of recharging ground water flow on the destabilising of slopes Leach amp Herbert
(1982) Kenney amp Lau (1984) and Reid and others (1985) focused attention on shortshy
term fluctuations in the water table that may cause abrupt failures in static slopes
(Hanegerg 1991) Terlien (1997) later followed up such investigations to reach four main
conclusions Firstly positive pressure heads are not capable of triggering landslides but
failed slopes are often located in such areas Secondly depths of failure depend on the
geotechnical properties of the siltsand content of the soil and the slope angle Thirdly
failure will occur only when the soil becomes saturated from the surface to the depth of
Investigation of land stability at Windermere Northern Tasmania 17
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
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Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 1 The effect of soil and water on slope stability
the potential slip surface (Terlien 1996) Fourthly the depth of saturation is dependent
upon soil profile the vertical soil moisture distribution prior to intense rainfall and the
amount and intensity of rainfall Terlien also recognised that perched water tables act as
triggering mechanisms for landslides where water is in contact with potential failure - _-~
surfaces thereby reducing frictional strength
A136 Problems associated with water models
The fIrst simplifying assumption made by Terzaghi in the 1950s is that slope failures are
initiated primarily by water infIltration into hill slopes However although such
infIltrations result in increased pore ytater pressure within the slope material before pore
pressure can be increased capillary pores must be full of water and have sufficient volume
to counteract soil suction (negative pore pressure)
The second assumption was that for any given slope a critical level of pore water
pressure (uwc) acting on a slope exists where the potential failure surface develops (Keefer
et al 1987) This assumed that the failure surface and piezometric surfaces are parallel to
the ground surface which is rarely the case
A third assumption that there is no surficial run-off (ie that all rain falling onto the slope
infIltrates) at least initially into a saturated plane above the potential failure plane
However the total rate of drainage is proportional to the thickness of the saturated zone
(Keller et al 1987) and care must be exercised however when using the infmite slope
model The magnitude of $r is often different in laboratory and field experiments and
appears to fall as the normal stresses increase This occurs because the residual strength
failure line is in fact a curve and not straight This is of fundamental importance on clay
slopes where landsliding occurs deep into the slope and the range of normal stress is large
due to the amount of overlying sediments so that a unique value of $r will not apply In
this case large rather than minor landslides will move on flatter slopes
Investigation of land stability at Windermere Northern Tasmania 18
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
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~II
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Ix)~lJo( bullbull~
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~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
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~ ~J
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) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
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~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
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Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
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Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
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Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
bull Appendix I The effect of soil and water on slope stability
Al4 Conclusion
The stability of slope surfaces is dependent upon the factors affecting the slip surface This
conclusion appears to be dependant upon strength parameters (c lt1gt) of the slope
material the height and inclination of the slope the density of the slope material (which
determines an) and the distribution of pore water on the slope o
The models discussed in this literature review are constrained primarily by the number
and variety of assumptions made by various authors to simplify the equations However
while they provide locally practical and reasonably realistic data for calculating angles of
response for particular soils on a regional scale such generalisations are not without risk
No two-soil types are exactly the same and the potential for failure must always be
examined closely on a local scale
o Soil mechanics technology applied to the study of slopes is concerned primarily with
processes that lead to slope failure by landsliding and with the stability analysis of the
failure However much remains to be discovered before the degree of stability of any
previously stable slope can be accurately predicted in either its natural state or after
modification by natural or artificial processes
Investigation of land stability at Windermere Northern Tasmania 19
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
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=
(1
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gt
~ gt
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t4 ~
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~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
APPENDIX 2 CLIMATIC RECORDS
BUREAU OF METEOROLOGY ACACIA HOUSE
Rainfall data obtained from Acacia House and Temperature data from Tea Tree Bend (Launceston)
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
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~
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0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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bullbullbull bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
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bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
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it-
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 2 Climatic records
Table A21 Table illustrating the total monthly precipitation (mm) for the Windennere area (top no) and the number of rain days (bottom no)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec I 1927I
i 585
13 814
17 1324
20 545
8 514
10 228
5 1232
10
I 1928 588
8 933
11 478
7 987
11 426
8 679
11 1175
16 829
16 1165
25 1583
21 473
15 140
4 9456
153
1929 I
719 14
416 8
357 8
2199 15
602 11
1483 19
937 15
1090 16
306 12
469 11
757 17
770 13
10105 159
) 1930 I 105 5
571 6
235 6
422 723 8
171 7
1664 1544 18
756 16
881 767 16
1348 13
9187 i
1931 146 250 1766 662 2526 2441 1320 837 1224 261 541 00 11974 12 7 11 7 21 17 14 14 19 9 7 0 138
1932 292 372 1021 971 76 1339 610 877 706 904 432 713 8313 5 9 11 14 2 16 15 14 8 15 6 6 121
1933 I
177 7
16 2
551 4
484 5
577 5
364 9
392 8
912 10
1168 9
539 6
178 3
422 10
5780 78
19341 I
310 4
254 2
211 5
804 9
144 2
160 3
1163 8
664 11
1036 11
1196 18
1032 9
734 8
7708 90
1935 268 789 346 837 895 802 600 726 435 290 439 246 6673 5 11 5 14 9 9 11 11 11 8 11 10 115
I 1936 208 4
126 4
289 4
650 8
503 12
530 10
657 14
2514 17
704 13
746 11
294 9
656 8
7877 114
I 1937 1033 286 619 162 843 239 898 625 542 657 259 1412 7575 7 4 7 3 11 3 10 11 11 9 4 12 middot92
1938 753 1159 457 666 562 1755 221 479 565 477 922 460 8476 6 5 3 6 10 12 8 10 9 9 9 6 93
1939 21 1019 721 658 798 737 528 2401 867 662 831 400 9643 I I 3 6 4 9 9 12 9 21 9 5 21 5 113 I 1940 557 153 178 419 366 664 1611 125 565 153 472 630 5893 i 6 3 4 7 5 9 14 3 5 5 5 5 71 1941 188 114 635 179 267 684 867 244 602 729 424 211 5144 4 2 6 3 5 6 12 5 12 7 5 7 741 i 1942 371 372 188 279 1198 1331 1964 958 653 609 76 531 8530 i
4 6 4 3 11 12 16 15 10 6 1 3 91
1943 334 7
1948 1459 1267 286 545 326 2540 978 539 183 466 608 10 6 10 6 17 13 8 10 9 9
i 1947
I 1948
406 6
87
243 3
364
753 11
193
369 4
33D
694 9
869
2170 16
635
2019 16
690
1221 16
610
463 11
837
1552 16
649
523 5
675
947 12
492
11360 125
6431 I 2 5 5 8 11 9 15 12 11 14 9 10 111
1949 423 697 470 127 898 446 418 433 313 1497 979 223 69241 5 7 5 2 8 7 11 12 9 19 16 6 1071
1950 523 457 249 249 590 254 478 605 683 1088 447 9 8 6 6 12 6 8 8 10 12 6
1951 00 264 165 973 785 270 1207 802 452 671 738 399 6726 I 0 4 2 11 7 21 13 11 10 10 7
1952 581 150 44 1105 1418 1418 1168 857 1617 1550 1758 206 11872 9 5 2 8 12 16 13 13 18 17 12 4 129
1953 671 23 148 471 1098 1634 1498 961 569 864 510 688 9135
I 3 2 -shy -
4 - 6
shy -10 16 15_shy
15 - shy
12 -- shy 13
-9 _ _ ~ ~ 116
-shy
3 8 7 8 7 16 16 14 7 8 8 9 111 1955 268 719 120 1103 1077 941 1141 2426 836 1720 797 817 11965
9 7 3 8 11 7 16 23 11 18 10 10 133 1956 656 594 961 2005 1385 1697 1014 1206 974 806 602 729 12629
9 4 6 10 7 14 13 16 9 14 8 10 I 120
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
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DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Appendix 5 Drill Logs
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bull Appendix 5 Drill Logs
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
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I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
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Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
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LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 2 Climatic records
Table A2 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec I 1957 232 292 683 1001 838 818 364 264 699 535 912 5731 7211 I 3 3 3 14 8 11 11 6 14 8 11 8 i 100 I 1958 61 493 439 313 3015 460 935 977 455 1474 633 4931 9748 I 2 4 8 3 24 6 15 11 8 15 6 81 110 i 1959 309 462 254 650 175 880 532 1111 380 562 404 826 6545
)
1960 5
330 4
5 824
5
4 188
8
8 1642
15
2 1670
14
12 677
11
14 1476
19
13 383
16
9 880
11
9 701
12
11 585
11
151 113
4
107 9469
130 1961 33 158 134 1252 279 649 827 751 272 664 366 771 6156
2 6 5 9 14 9 9 10 6 9 9 10 98 1962 570 451 375 290 1499 1283 533 1186 611 1668 437 232 9135
6 6 11 7 15 22 12 13 10 17 10 5 134 1963 790 493 555 71 414 308 1562 1051 1306 611 472 342 7975
10 6 9 3 7 6 10 11 11 9 6 5 93 1964 129 1600 809 280 621 1446 1751 783 1235 653 397 641 10345
3 11 6 6 8 15 17 8 12 10 5 8 109 1965 62 15 394 879 1290 466 683 457 881 495 582 582 6783
3 1 7 9 15 11 7 11 7 8 8 1966 107 330 421 397 820 343 1548 776 1212 554 348 617 7473
4 5 11 5 6 7 14 9 10 4 3 5 83 i 1967 351 190 66 149 322 272 1347 937 301 406 242 549 5132
4 2 2 5 5 10 17 16 10 5 5 10 91 1968 125 749 532 1100 1191 1054 974 2214 544 1008 1094 120 10705
3 3 8 19 13 8 12 19 11 12 12 3 123 I 1969 584 1274 353 465 1501 241 1217 861 643 651 569 397 8756
) 1970
5 748
11 462
8 553
9 919
11 675
9 966
18 1311
18 1781
10 661
6 552
12 643
7 1217
124 10488
8 4 8 10 9 11 11 14 5 8 3 7 98 I 1971 427 277 263 1524 881 1164 285 886 1036 1361 1260 1079 10443 I 2 2 3 9 3 9 4 4 3 I 1972 257 899 00 272 277 572 998 726 343 262 241 00 4847
2 0 1 0 I 1973 742 201 89 1311 749 2169 1626 401 1179
1974 460 304 66 721 978 700 1800 696 1760 652 896 1492 10525
1975 33 440 511 252 954 350 1134 2345 1014 870 1068 458 9429
1976 606 41 00 417 1125 00 329 765 700 597 881 1140 6801 I 0 0
1977 742 1040 90 963 658 723 986 478 290 300 30
1978 313 889 365 775 722 728 1163 847 880 582 731 546 8541 I
I 1979 650 278 451 763 888 624 1114 440 1286 1143 6
206 190 8033
I 1980 286 214 420 1342 529 667 1212 1040 868 448 328 392 7746
II
I 1981
1 240
4 180
6 446
3 336
8 572
5 3 4 5 3 2 11 45 1
1 2 2 1 I
I
1986
1987 642 9
116 5
442 7
884 13
198 7
1058 13
1012 8
316 9
610 10
1372 17
1094 13
834 11
396 8
662 15
164 6
1204 15
406 8
354 8
836 10
574 I
I 111 ---l
i
1988 134 02 394 1567 1124 1415 712 898 822 964 794 I I 2 o 8 16 10 18 8 _ -----J
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
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DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Appendix 5 Drill Logs
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bull Appendix 5 Drill Logs
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
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I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
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Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
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LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 2 Climatic records
Table A21 continued
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec
1989 432 40 450 1706 488 806 1150 714 798 668 712 458 7 3 11 13 14 11 6
1990 92 342 250 570 396 1188 913 1534 382 570 628 382 3 7 4 8 5 6 8
1991 1240 18 486 224 72 1466 600 1904 648 256 494 360 8 1 10 2 8
1992 234 286 46 1538 1290 562 1426 1110 1032 824 1070 698 1 6 5 3 10 7
1993 356 590 242 212 846 452 1036 764 712 838 866 1356 8 11 12 6 8
1994 570 236 50 366 920 570 594 372 96 523 640 114 2 8 15 13 4 9 8 8 11 1
1995 832 394 190 600 1124 1004 608 682 540 402 540 9 7 5 9 13 11 14 16 12 9 7
1996 1514 732 566 594 146 908 868 1316 1127 682 380 174 8 7 8 11 6 13 16 22 17 14 6 5
1997 912 250 178 258 1670 376 442 562 1046 289 428 130 11 4 9 6 12 9 7 13 18 12 8 6 LL
I
Summary of Total Monthly Precipitation using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec A
Mean 420 455 405 685 852 816 1048 967 755 741 608 562 Median 343 353 361 594 809 667 1036 847 699 653 544 531 Highest 1514 1600 1766 2199 3015 2441 2540 2514 1760 1720 1758 1492 Lowest 00 15 00 71 72 00 221 125 96 153 76 00 Number 60 62 62 63 62 63 63 63 63 62 61 61
Summary of Rain Days using available data between 1927 and 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec A
Mean 56 52 57 80 92 103 130 129 109 107 82 72 Median 50 50 55 80 90 100 140 130 105 100 80 75 Highest 14 11 11 19 24 22 21 23 25 21 21 15 Lowest 0 1 0 2 1 0 3 3 5 3 1 0 Number 52 52 54 52 49 52 49 49 48 51 53 52
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
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location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
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bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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DIAMOND DRILLCORE LOG project hole no location page of logged by date
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
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description
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
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Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
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Figure A72 illustrates the soil classification according to the shear strength of
sediments
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Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 2 Climatic records
Table A23 Maximum and minimum temperature range for the Launceston area including long term averages
Maximum Temperature from 9am (OC) Minimum Temperature to 9am (OC)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Avg Max Mln Total Nbr ----=------=-~--__ _ -- _-_- ------ -__-- -
Jan 1998 270 273 244 238 248 256 266 274 264 315 298 302 304 254 254 246 313 307 224 252 258 278 240 237 216 229 274 179 193 224 212 - 25~ 3151 1791 31
156 163 99 80 116 102 107 150 117 156 160 180 192 203 145 138 106 152 143 153 160 135 147 107 138 124 105 149 74 172 ~~ ~1_l-_~~3+__41------- 31 Feb 1998 262 292 236 234 284 274 282 210 266 227 255 220 210 238 215 191 204 226 209 196 198 186 217 240 282 310 192 225 235 310 186 28
94 137 95 99 121122 151158 90 143 135 170 113 130 135 112 60 124 133 108 71110 75 97127121131 44 11S ~h~--- 28
Mar 1998 255 253 277 232 181 214 208 270 288 262 277 323 232 203 167 205 213 246 224 216 234 267 179 186 232 231 199 195 210 201 16 227 32a_~51 31 80 112 122 156 83 117 92 63 64 82 87 89 137 130 44 52 77 80 93 106 89 138 164 47 75 75 95 115 84 95 11
r-APr 199-8t-----18-4-2-1-2---------22----0-2--1C1- 21-9-=--2c-1--6---1-=-96----21-2=--1----8----7=--=2----1--=2-1-=-7-=-0------15=-0-=--1-5--6-1----8-3-19-2-16=-9-=--1-9-5---1-=-9-2------15---2 --1-6-2-1----8--=0--1=-8-4-15-3-1----5----6-1----59-----16=--=-7-16-0-1--=5-3------1-6-6-14-----1--j 10 ~~I -1~t----middot ~ 1 i I I 65 50 100 39 95 54 70 92 20 34 60 97 117 57 59 29 64 45 61 91 106 73 28 59 90 121 66 68 90 107 7(j 121j 2~ J(J
May 1998 144 181 173 172 156 165 130 123 160 148 144 170 132 181 184 190 156 170 166 157 189 149 135 158 158 141 149 147 145 164 126 157r--w-oi 1231 -3i~ 10 15 24 44 75 25 32 -05 19 -08 04 18 42 55 67 97 69 78 95 110 75 16 27 72 56 10 23 104 124 90 -D --- --~--=--=- ~f2~+_ -~--- L __3~
Jun 1998 150 114 98 152 172 143 121 128 131 105 130 115 141 131 115 118 117 155 135 137 134 102 100 108 124 110 119 112 155 117 J 126 1721 98 30 (
02 -10 02 23 86 116 88 56 -02 09 49 80 50 43 54 14 -15 -06 04 15 38 30 36 56 75 -15 -06 34 39 10 3 ~ -__ ~5~__ 30 Jul 1998 118 1431-4-0-130 140 155 130 123 1ci4 103-26-136 120 -=-11-1--1---4-=7-122 140 11-=-8------=-10=-2=-----=94 129 130 139 123 123 152 132 110 136 140 1601 128j 1601 94 31
-14 -17 -07 00 15 35 40 90 55 00 -30 -22 10 24 11 -30 -16 00 00 -03 -02 11 -20 -09 -10 42 59 85 44 -12 4(1 12 9d -30 31
Aug 1998 12X-139-137-14-0-1-5-4-1-3-5150-15-2-middot-i3T14-31-1--8-1-18 138 110 1-2----7=--1-=-3--=7----15=-=-3-1----6--0=--10=-58 148 150 128 137 158 176 174 156 175 160-13-7 -14417~110t-middotmiddot 30
-10 10 62 98 40 21 36 16 20 48 28 04 -14 15 middot10 -08 08 16 -06 38 80 30 -10 25 12 05 35 84 30 8 2 9aI -f40 30r---+---+---+----------j
158 198 168 163 150 161 158 175 154 164 202 183 181 139 99 134 148 176 152 166 174 188 163 202 99J 1 221 68 55 87 101 42 44 65 15 10 45 30 81 106 70 36 04 64 102 76 24 15 73 137 l _5 13 04J l 23------------------ _---__------------___---shy
Geological investigation and slope risk assessment at Windermere northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
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z~
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t4
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
------------------------------------------ ---------------
Appendix 2 Climatic records
Table A22 Daily amount of precipitation in the Windermere area during 1998
Precipitation to 9am (mm) Period over which Precipitation has accumulated (days)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 _ ~- -_shy -__ ---_ -----shy ----shy bull_ -- ------------------------------------ -- bull
Jn 1998 00 00 00 00 00 00 00 00 00 00 00 00 00 00 172 00 00 00 00 00 00 00 14 00
1 1 Feb 1998 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 214 08 00 00 14 00 04 00 00
1 1 1 1 1 r1998 00 00 00 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104
1 1--__-+-shy 1998 00 00 00 00 00 00 02 02 00 00 00 00 360 00 00 00 00 00 00 58 118 28 00 00 ~-__-~ 1 1 1 1 1 1 y 1998 74 00 00 00 00 10 00 00 00 00 00 06 00 00 00 00 00 04 00 00 92 00 142
1 1 1 1 2 1
Jun 1998 00 00 00 00 04 64 214 00 00 00 00 24 124 46 64 10 00 00 02 00 62 88 00 52
1 1 1 1 1 1 1 1 1 1 1 1 Jul1998 00 00 00 00 24 236 00 16 52 00 00 00 00 00 00 00 00 12 04 00 98 03 00
1 1 1 1 1 1 2 1 Aug 1998 00 00 116 22 58 00 00 00 00 78 00 00 00 00 00 00 00 00 00 00 124 04 04
1 1 1 2 1 1 1- ---- ___~-- --_--shy ---__---_
25
04
1 00
00
00
58
1 18
1 12
1 00
26 27 28 29 30 31 ----bull------ I
38 00 192 78 10 00
1 1 1 1 00 00 00
00 00 00 00 00
1330 00 00 24
1 2 00 00 00 24 24 02
1 1 1 00 27 00 100 00
1 1 00 112 146 206 00 00
1 1 1 I 00 00 00 00 00 0amp
__ 1j
Avg Max Mln Total Nbr
8middot1middot O-~I--shy
508 31 I
71 7 20 310 001 5501 2sj
I
10 1 1 5i 5 04 104 00 124i 31
1
10 1 1 3i 3 32 360 00 922 29 11 1
8shy~ 9i
15
142 00 436 30 I
i 11 it 1 11t ~
30 214 O~I 899 30i
10 1 15i~ 31 236 00 9211 30
2 I
11 1 13 12 r-shyI 14[ 124 00 412 30
1 2 1 ____ ~ __ 8
Geological investigation and slope risk assessment at Windermere northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
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6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
-)
APPENDIX 3 GRID METHOD RESULTS
Dates of measuring 1) 23rd April 1998 2) 8th June 1998 3) 11 th July 1998 4) 29th August 1998
The method by which this data was derived is outlined in section 63
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
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DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Appendix 5 Drill Logs
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bull Appendix 5 Drill Logs
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
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I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
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Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
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LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
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Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 3 Recording 1 23rd April 1998
peg east north Z first_x firsCY firsCz second second seconc calc dis meas dist 11 11amp22 0 0 100 22653 19815 9204 31131 3179 0658935 21 2181 9565 11amp21 0 0 100 o 21811 9565 2224 2224 00002911 31 3144 9017 11amp12 0 0 100 22198 o 9631 22504 2262 0116431 41 5108 8542 21amp12 o 2181 957 22198 o 9631 31127 3167 05427391 22 22653 1982 9204 21amp22 o 2181 957 22653 19815 9204 23025 225 0525231 12 22198 9631 21amp32 o 2181 957 23 30443 9307 24702 32 23 3044 9307 21amp31 o 2181 957 o 31442 9017 11083 1108 0003362 42 21319_ 8538 31amp22 o 3144 902 22653 19815 9204 25531 13 44646 1002 31amp33 o 3144 902 4793 31487 9172 47955 23 48 1642 9228 31amp42 o 3144 902 21319 48881 8538 27957 33 4793 3149 9172 31amp41 o 3144 902 o 51079 8542 20203 202 0003383
) 43 47287 5643 8558 41amp42 o 5108 854 21319 48881 8538 21432 2143 0002369 14 67075 9611 41amp32 o 5108 854 23 30443 9307 31834 24 7097 1758 9253 12amp13 222 o 963 44646 o 1002 22775 2323 0454825middot 34 73963 3109 9259 12amp23 222 o 963 48 1642 9228 30847 3102 0172586 44 64796 5065 8674 12amp22 222 o 963 22653 19815 9204 20274 2029 00157991 15 91077 9942 22amp23 2265 1982 92 48 1642 9228 25575 2558 0005151middot 25 92314 1775 972 22amp13 2265 1982 92 44646 o 1002 30695 3114 0444829middot 35 94285 2694 8811 22amp32 2265 1982 92 23 30443 9307 10683 112 0517049 45 90887 513 8491 32amp33 23 3044 931 4793 31487 9172 24988 2413 0857882middot 16 11491 9318 32amp42 23 3044 931 21319 48881 8538 2005 2006 0O10262 26 11329 1486 9132 13amp14 4465 0 100 67075 o 9611 22792 2323 0438447 36 10774 2672 9226 13amp23 4465 0 100 48 1642 9228 18518 1945 0932494 46 11313 4518 9041 13amp24 4465 0 100 7097 17578 9253 3256 3309 0530280 17 13565 102 23amp24 48 1642 923 7097 17578 9253 23001 2302 0019223middot 27 13525 1542 9244 23amp33 48 1642 923 4793 31487 9172 15077 1508 0002532
37 13076 2877 9241 23amp34 48 1642 923 73963 31087 9259 29821 2955 0270873 47 12905 3863 8954 33amp34 4793 3149 917 73963 31087 9259 26051 2676 0709255middot 18 1557 1062 33amp43 4793 3149 917 47287 56432 8558 25699 257 0001405 28 154 1823 9435 33amp44 4793 3149 917 64796 50648 8674 26007 2601 0002857 38 15622 3286 8675 14amp15 6708 o 961 91077 o 9942 24229 2422 0008515 48 14487 4188 8667 14amp25 6708 o 961 92314 17747 972 30873 3114 0267066 19 17283 9786 14amp24 6708 o 961 7097 17578 9253 18357 1804 0317045 29 17334 1635 9079 24amp25 7097 1758 925 92314 17747 972 2185 2184 0009743 39 16893 2632 9028 24amp34 7097 1758 925 73963 31087 9259 13837 49 1734 406 8591 24amp15 7097 1758 925 91077 o 9942 27582 2823 0648167
34amp35 7396 3109 926 94285 26944 8811 2122 2157 0349760 34amp25 7396 3109 926 92314 17747 972 23151 2254 0610581 15amp16 9108 o 994 11491 o 9318 24639 2464 0001004 15amp26 9108 o 994 11329 1486 9132 27929 2787 0059152 15amp25 9108 o 994 92314 17747 972 17928 1801 0081826 25amp16 9231 1775 972 11491 o 9318 29013 2952 050q886 25amp26 9231 1775 972 11329 1486 9132 21977 2169 0287414
) 25amp35 9231 1775 972 94285 26944 8811 13082 1309 0007530 25amp36 9231 1775 972 10774 26725 9226 18522 1852 000238 35amp26 9428 2694 881 11329 1486 9132 22751 2249 0260715 35amp36 9428 2694 881 10774 26725 9226 14086 1668 2593869 35amp46 9428 2694 881 11313 45176 9041 26323 2601 0312621 35amp45 9428 2694 881 90887 51302 8491 24801 248 0000665 45amp35 9089 513 849 94285 26944 8811 24801 248 000066
45amp36 9089 513 849 10774 26725 9226 30695 2994 0754704
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
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z~
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t4
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 3 Recording I 23rd April 1998
45amp46 9089 513 849 11313 45176 9041 23718 2372 0001642 16amp17 1149 o 932 13565 0 102 22516 2253 0013921 16amp26 1149 o 932 11329 1486 9132 15064 1491 015397 26amp17 1133 1486 913 13565 0 102 28877 2887 0006683 26amp27 1133 1486 913 13525 15418 9244 21998 2292 0922416 26amp36 1133 1486 913 10774 26725 9226 13132 1314 0008035 26amp37 1133 1486 913 13076 28775 9241 22362 2221 0152316 36amp26 1077 2672 923 11329 1486 9132 13132 1314 0008035 36amp37 1077 2672 923 13076 28775 9241 23112 2328 0168264 36amp46 1077 2672 923 11313 45176 9041 1931 2005 07397 36amp47 1077 2672 923 12905 38628 8954 2456 246 004038 46amp37 1131 4518 904 13076 28775 9241 24164 2459 0426247 46amp47 1131 4518 904 12905 38628 8954 17238 1798 0742066 17amp18 1356 0 102 1557 o 1062 20501 2049 0011087 17amp28 1356 0 102 154 18229 9435 26964 2699 00261 17amp27 1356 0 102 13525 15418 9244 18125 1767 0455056 27amp18 1353 1542 924 1557 o 1062 29091 2907 0021229 27amp28 1353 1542 924 154 18229 9435 19056 1924 0184409 27amp37 1353 1542 924 13076 28775 9241 14092 1404 0051517middot 37amp38 1308 2877 924 154 18229 9435 25595 251 0494699middot 37amp47 1308 2877 924 12905 38628 8954 10403 47amp48 1291 3863 895 14487 41876 8667 16399 1683 0430615 18amp19 1557 0 106 17283 o 9786 19074 1906 0013500 18amp28 1557 0 106 154 18229 9435 21832 2152 031211 18amp29 1557 0 106 17334 16354 9079 28595 288 0205145 28amp29 154 1823 944 17334 16354 9079 19748 1973 0017515 28amp19 154 1823 944 17283 o 9786 26437 2644 0002800 28amp39 154 1823 944 16893 26316 9028 17454 1701 0444430 39amp38 1689 2632 903 15622 32862 8675 14719 1533 0610652 19amp29 1728 o 979 17334 16354 9079 17826 178 0026182 29amp39 1733 1635 908 16893 26316 9028 10906 10 0905866 39amp49 1689 2632 903 1734 40603 8591 15597 1652 0923096 38amp49 1562 3286 867 1734 40603 8591 18854 1883 002414
Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
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location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Appendix 5 Drill Logs
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bull Appendix 5 Drill Logs
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location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
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Appendix 5 Drill Logs
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
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I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
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Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
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Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 3 Recording 2 8th June 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 22653 1982 9204 3113442 315 0365 21 0 218 9565 11amp21 0 0 100 0 218 9565 2222977 2228 0050~
31 o 3144 9017 11amp12 0 0 100 22198 0 9631 2250261 226 0097 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3111956 315 0380 22 2265 1982 9204 21amp22 0 218 9565 22653 1982 9204 2302414 229 0124 12 222 0 9631 21amp32 0 218 9565 219 3044 9307 2368367 32 219 3044 9307 21amp31 0 218 9565 0 3144 9017 1108873 111 001 42 2132 4898 8538 31amp22 0 3144 9017 22653 1982 9204 2552802
13 4465 0 1022 31amp33 0 3144 9017 4793 3249 9172 4796655
23 48 1742 9228 31amp42 0 3144 9017 21319 4898 8538 2801955
33 4793 3249 9172 31amp41 0 3144 9017 0 5108 8542 2020624 2015 0056~
-- 43 465 5743 8558 41amp42 0 5108 8542 21319 4898 8538 2142222 214 0022~
14 6708 0 9611 41amp32 0 5108 8542 219 3044 9307 3105064
24 7197 1798 9253 12amp13 222 0 9631 44646 0 1022 2320786 2325 0042
34 725 3209 9259 12amp23 222 0 9631 48 1742 9228 3139173 3204 0648~
44 652 5265 8674 12amp22 222 0 9631 22653 1982 9204 2027985 203 0020
15 912 0 9942 22amp23 2265 1982 9204 48 1742 9228 254615 255 0038middot
25 9331 1775 972 22amp13 2265 1982 9204 44646 0 1022 3130096 3115 0150
35 9229 28 8811 22amp32 2265 1982 9204 219 3044 9307 1069637 1107 037
45 92 5232 8491 32amp33 219 3044 9307 4793 3249 9172 2614548 259 0245
16 1159 0 9318 32amp42 219 3044 9307 21319 4898 8538 2007997 2013 00501
26 1149 1486 9132 13amp14 4465 0 1022 67075 0 9611 2324109 2325 0008
36 110 2712 9226 13amp23 4465 0 1022 48 1742 9228 2032516 1995 0375
46 1128 4618 9041 13amp24 4465 0 1022 7197 1798 9253 3410851 3385 0258
17 137 0 102 23amp24 48 1742 9228 7197 1798 9253 2397784 2385 01271
27 1379 1542 9244 23amp33 48 1742 9228 4793 3249 9172 1508056 1512 0039
37 1368 2977 9241 23amp34 48 1742 9228 725 3209 9259 2855792 2879 02321
47 1321 3963 8954 33amp34 4793 3249 9172 725 3209 9259 2458865 2452 0068
18 1577 0 1062 33amp43 4793 3249 9172 465 5743 8558 2572447 2568 004shy
28 1563 1823 9435 33amp44 4793 3249 9172 652 5265 8674 2700887 2692 00881
38 1572 3286 8675 14amp15 6708 0 9611 912 0 9942 2435101 2442 0068
48 1479 4188 8667 14amp25 6708 0 9611 93314 1775 972 3169757 3155 0147
19 175 0 9786 14amp24 6708 0 9611 7197 1798 9253 1897519 1872 0255
29 1753 1635 9079 24amp25 7197 1798 9253 93314 1775 972 2185013 219 0041
39 1709 2632 9028 24amp34 7197 1798 9253 725 3209 9259 1412008
49 1754 406 8591 24amp15 7197 1798 9253 912 0 9942 2721296 2715 0062
34amp35 725 3209 9259 92285 28 8811 2069407 2093 0235
34amp25 725 3209 9259 93314 1775 972 2569261 2558 01121
15amp16 912 0 9942 11591 0 9318 2548572 254 0085
15amp26 912 0 9942 1149 1486 9132 2912249 2902 010
15amp25 912 0 9942 93314 1775 972 1801277 179 0112
25amp16 9331 1775 972 11591 0 9318 2901383 2918 0t66
25amp26 9331 1775 972 1149 1486 9132 2255841 226 0041
25amp35 9331 1775 972 92285 28 8811 1373861 1346 0278
25amp36 9331 1775 972 110 2712 9226 1976419 2014 0375
35amp26 9229 28 8811 1149 1486 9132 2635151 2626 0091
35amp36 9229 28 8811 110 2712 9226 1821588 1817 0045
35amp46 9229 28 8811 11283 4618 9041 2752997 2722 0309
35amp45 9229 28 8811 92 5232 8491 2453128 2501 0478
45amp36 92 5232 8491 110 2712 9226 3182864 3164 0188
45amp46 92 5232 8491 11283 4618 9041 2240175 2252 0118
Geological investigation and slope risk assessment at Windermere northern Tasmania
J
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
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Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
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Appendix 5 Drill Logs
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bull Appendix 5 Drill Logs
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Appendix 5 Drill Logs
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Appendix 5 Drill Logs
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1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
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0
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~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 3 Recording 2 8th June 1998
16amp17 1159 0 9318 137 0 102 2286002 2295 0089 16amp26 1159 0 9318 1149 1486 9132 1500997 1491 0099 26amp17 1149 1486 9132 137 0 102 2869307 2889 0196 26amp27 1149 1486 9132 13785 15418 9244 2298409 237 0715 26amp37 1149 1486 9132 13676 29n 9241 2648312 26 0483shy
36amp26 110 2712 9226 1149 1486 9132 1323636 36amp37 110 2712 9226 13676 29n 9241 2689131 2642 0471 36amp46 110 2712 9226 11283 4618 9041 1935756 199 0542 36amp47 110 2712 9226 13205 3963 8954 2549708 2524 0257( 46amp37 1128 4618 9041 13676 29n 9241 2908493 2864 0444 46amp47 1128 4618 9041 13205 3963 8954 2032407 2096 0635 17amp18 137 0 102 1577 0 1062 2112179 212 0078 17amp28 137 0 102 15627 1823 9435 2760n6 2731 029 17amp27 137 0 102 13785 15418 9244 1816125 1875 0588
27amp18 1379 15418 9244 1577 0 1062 286544 289 0245
27amp28 1379 15418 9244 15627 1823 9435 1873104 1935 0618
27amp37 1379 15418 9244 13676 29n 9241 1439336
37amp38 1368 29n 9241 15722 3286 8675 2145216 2114 0312
37amp47 1368 29n 9241 13205 3963 8954 1129781
47amp48 1321 3963 8954 1479 4188 8667 1626413 1635 00851 18amp19 1577 0 1062 175 0 9786 1920535 1965 0444pound
18amp28 1577 0 1062 15627 1823 9435 2178991 2155 0239
18amp29 1577 0 1062 17534 1635 9079 2856502 2882 0254
28amp29 1563 1823 9435 17534 1635 9079 1949033 196 0109pound
28amp19 1563 1823 9435 175 0 9786 2637169 2647 0098
28amp39 1563 1823 9435 1709 2632 9028 172061 1705 0156
39amp38 1709 2632 9028 15722 3286 8675 1556839 1552 0048
19amp29 175 0 9786 17534 1635 9079 1781637 1782 0003pound
29amp39 1753 1635 9079 1709 2632 9028 1092587 1073 01951
39amp49 1709 2632 9028 1754 406 8591 1559696 162 0603(
38amp49 1572 3286 8675 1754 406 8591 19n69 199 0123
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
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scale I ~ 11YI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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6 D J 11 )
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pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 3 Recording 3 11th July 1998
peg east north z first x first y first z second x second y second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132 3115 0017 21 0 218 9565 11amp21 0 0 100 0 218 9565 2223 2225 002C 31 o 3144 9017 11amp12 0 0 100 22198 0 9631 22503 2255 0047 41 o 5108 8542 21amp12 0 218 9565 22198 0 9631 3112 3165 053C 22 2265 1982 9204 21amp22 0 218 9565 2265 1982 9204 23021 225 0521 12 222 o 9631 21amp32 0 218 9565 23 3044 9307 24704 32 23 3044 9307 21amp31 0 218 9565 0 3144 9017 11089 1115 OOE 42 214 493 8538 31amp22 0 3144 9017 2265 1982 9204 25525 13 4465 0 1002 31amp33 0 3144 9017 478 339 917 47888 23 4805 1742 9228 31amp42 0 3144 9017 214 493 8538 28282 33 478 339 917 31amp41 0 3144 9017 0 5108 8542 20206 202 OOOE 43 462 5878 8558 41amp42 0 5108 8542 214 493 8538 21474 214 007~
14 6708 o 9611 41amp32 0 5108 8542 23 3044 9307 31836 24 723 1798 9253 12amp13 222 o 9631 44646 0 1002 22783 232 0417 34 722 3253 9259 12amp23 222 o 9631 4805 1742 9228 31433 314 003~
44 6554 53 8674 12amp22 222 o 9631 2265 1982 9204 2028 2028 OOOC 15 913 o 9942 22amp23 2265 1982 9204 4805 1742 9228 25514 2564 012 25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712 3112 0407 35 92 291 8811 22amp32 2265 1982 9204 23 3044 9307 10676 1132 06M 45 9205 5317 8491 32amp33 23 3044 9307 478 339 917 25078 25657 osn 16 117 o 9381 32amp42 23 3044 9307 214 493 8538 2043 201 033C 26 1149 149 9132 13amp14 4465 o 1002 6708 0 9611 22804 233 049E 36 1111 2805 9226 13amp23 4465 o 1002 4805 1742 9228 19436 194 003E
- 46 1111 473 9041 13amp24 4465 o 1002 723 1798 9253 33865 3312 074E 17 142 0 102 23amp24 4805 1742 9228 723 1798 9253 24258 242 005i 27 1362 15 9244 23amp33 4805 1742 9228 478 339 917 16492 1722 072i 37 1373 3002 9241 23amp34 4805 1742 9228 722 3253 9259 28489 2797 051 47 1348 4009 8954 33amp34 478 339 917 722 3253 9259 24455 2502 056 18 1578 0 1062 33amp43 478 339 917 462 5878 8558 25672 2598 030E 28 157 183 9435 33amp44 478 339 917 6554 53 8674 26535 265 003 38 1579 331 8675 14amp15 6708 o 9611 913 0 9942 24445 2435 009E
48 1443 4222 8667 14amp25 6708 o 9611 9331 179 972 31774 316 017~
19 1769 o 9786 14amp24 6708 o 9611 723 1798 9253 19062 1842 064 29 1767 1635 9079 24amp25 723 1798 9253 9331 179 972 21523 2225 072~
39 1723 2632 9028 24amp34 723 1798 9253 722 3253 9259 1455 49 1766 407 8591 24amp15 723 1798 9253 913 0 9942 27051 2723 017
34amp35 722 3253 9259 92 291 8811 20588 2043 0151 34amp25 722 3253 9259 9331 179 972 26094 2545 06~
15amp16 913 o 9942 117 0 9381 26305 266 029~ 15amp26 913 o 9942 1149 149 9132 29062 2885 021
15amp25 913 o 9942 9331 179 972 18149 1809 005
25amp16 9331 179 972 117 0 9381 29885 295 0381
25amp26 9331 179 972 1149 149 9132 22577 226 002 25amp35 9331 179 972 92 291 8811 14484 1513 06shy25amp36 9331 179 972 11109 2805 9226 21061 215 043
35amp26 92 291 8811 1149 149 9132 27136 2742 028
35amp36 92 291 8811 11109 2805 9226 19564 2004 047
35amp46 92 291 8811 1111 473 9041 26483 2668 019
35amp45 92 291 8811 9205 5317 8491 24282 2517 088i
45amp36 9205 5317 8491 11109 2805 9226 32366 3258 021
45amp46 9205 5317 8491 1111 473 9041 20679 209 022
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
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~II
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Ix)~lJo( bullbull~
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~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
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~ ~J
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) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
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~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
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Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
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Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
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Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 3 Recording 3 11th July 1998
16amp17 117 o 9381 142 0 102 26307 2602 0287 16amp26 117 o 9381 1149 149 9132 15252 1503 02211 26amp17 1149 149 9132 142 0 102 32718 3205 0668 26amp27 1149 149 9132 1362 15 9244 2133 219 0570 26amp37 1149 149 9132 1373 3002 9241 27047 2675 0297middot 36amp26 1111 2805 9226 1149 149 9132 13723 36amp37 1111 2805 9226 1373 3002 9241 26284 259 0384 36amp46 1111 2805 9226 1111 473 9041 19339 203 0961 36amp47 1111 2805 9226 1348 4009 8954 26731 2672 00101 46amp37 1111 473 9041 1373 3002 9241 31449 3207 0621 ( 46amp47 1111 473 9041 1348 4009 8954 24788 256 0812 17amp18 142 0 102 1578 0 1062 16349 1705 0701
) 17amp28 142 0 102 157 183 9435 24868 25 013 17amp27 142 0 102 1362 15 9244 18709 181 0609 27amp18 1362 15 9244 1578 0 1062 2968 2907 0609 27amp28 1362 15 9244 157 183 9435 21147 213 015 27amp37 1362 15 9244 1373 3002 9241 1506 1504 0020 37amp38 1373 3002 9241 157 183 9435 23005 2313 0125 37amp47 1373 3002 9241 1348 4009 8954 10765 47amp48 1348 4009 8954 1443 4222 8667 1015 18amp19 1578 o 1062 17685 0 9786 20796 208 OOO~
18amp28 1578 o 1062 157 183 9435 21816 215 0316 18amp29 1578 o 1062 1767 1635 9079 2936 288 05591 28amp29 157 183 9435 1767 1635 9079 20114 197 04131 28amp19 157 183 9435 17685 0 9786 27226 2643 0795 28amp39 157 183 9435 17233 2632 9028 17773 1702 0753 39amp38 1723 2632 9028 1579 331 8675 1633 1633 0000
) 19amp29 1769 o 9786 1767 1635 9079 17814 178 0013~
29amp39 1767 1635 9079 17233 2632 9028 10898 1005 0847E 39amp49 1723 2632 9028 1766 407 8591 15624 1645 08251 38amp49 1579 331 8675 1766 407 8591 20203 2002 01821
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
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gt
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=
(1
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gt
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t4 ~
0
0
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 3 recording 4 29th August a998
peg east north z first x first y first z second second_ second z calc dist meas dist 11 0 0 100 11amp22 0 0 100 2265 1982 9204 31132242 3115 001 21 0 218 957 11amp21 0 0 100 0 218 9565 22229766 2225 002( 31 0 3144 902 11amp12 0 0 100 22198 0 9631 22502607 2255 004 41 0 5108 854 21amp12 0 218 9565 22198 0 9631 31119557 3135 023( 22 2265 1982 92 21amp22 0 218 9565 2265 1982 9204 23021186 233 027f 12 22198 o 963 21amp32 0 218 9565 23 3044 9307 24704372
32 23 3044 931 21amp31 0 218 9565 0 3144 9017 11088733 1115 006 42 214 493 854 31amp22 0 3144 9017 2265 1982 9204 25525356
13 44646 0 100 31amp33 0 3144 9017 478 345 917 47922276
23 4805 1822 923 31amp42 0 3144 9017 214 493 8538 28282215
33 478 345 917 31amp41 0 3144 9017 0 5108 8542 20206239 202 000pound ) 43 458 5948 856 41amp42 0 5108 8542 214 493 8538 21473938 214 007~
14 6708 o 961 41amp32 0 5108 8542 23 3044 9307 31836019
24 723 1798 925 12amp13 22198 0 9631 44646 0 1002 22782555 232 041
34 722 3293 926 12amp23 22198 0 9631 4805 1822 9228 31883149 314 048~
44 6594 537 867 12amp22 22198 0 9631 2265 1982 9204 20279783 2028 OOO( 15 913 o 994 22amp23 2265 1982 9204 4805 1822 9228 25451475 2564 018f
25 9331 179 972 22amp13 2265 1982 9204 44646 0 1002 30712245 3112 040
35 92 2983 881 22amp32 2265 1982 9204 23 3044 9307 1067557 1132 06
45 9205 5402 849 32amp33 23 3044 9307 478 345 917 25167449 25657 048
16 117 o 938 32amp42 23 3044 9307 214 493 8538 20430264 201 033(
26 1149 149 913 13amp14 44646 0 1002 6708 0 9611 22803782 233 049pound
36 11109 2805 923 13amp23 44646 0 1002 4805 1822 9228 20156439 194 075pound
46 1111 473 904 13amp24 44646 0 1002 723 1798 9253 33865218 3312 074pound
17 142 0 102 23amp24 4805 1822 9228 723 1798 9253 24252476 242 005~
27 1362 15 924 23amp33 4805 1822 9228 478 345 917 16292247 1622 007~
37 1363 3052 924 23amp34 4805 1822 9228 722 3293 9259 28279015 2797 03m
47 1348 4065 895 33amp34 478 345 917 722 3293 9259 24466651 2502 055~
18 1578 0 106 33amp43 478 345 917 458 5948 8558 25796411 2598 018~
28 157 183 944 33amp44 478 345 917 6594 537middot 8674 26875662 265 0371
38 1579 331 868 14amp15 6708 0 9611 913 0 9942 24445132 2435 0091
48 1443 4222 867 14amp25 6708 0 9611 9331 179 972 31774376 316 017
19 17685 o 979 14amp24 6708 0 9611 723 1798 9253 19061616 1842 064
29 1767 1635 908 24amp25 723 1798 9253 9331 179 972 21522904 2125 027
39 17233 2632 903 24amp34 723 1798 9253 722 3293 9259 14950455
49 1766 407 859 24amp15 723 1798 9253 913 0 9942 27050924 2723 017
34amp35 722 3293 9259 92 2983 8811 20535832 2043 010
34amp25 722 3293 9259 9331 179 972 26320811 2545 087(
15amp16 913 0 9942 117 0 9381 26305172 266 029
15amp26 913 0 9942 1149 149 9132 29061659 2885 021
15amp25 913 0 9942 9331 179 972 18148788 1809 005l
25amp16 9331 179 972 117 0 9381 29885083 295 0381
25amp26 9331 179 972 1149 149 9132 22576592 226 002
25amp35 9331 179 972 92 2983 8811 15055534 1513 007shy
25amp36 9331 179 972 11109 2805 9226 21060734 215 043
35amp26 92 2983 8811 1149 149 9132 2752488 2742 011
35amp36 92 2983 8811 11109 2805 9226 19616804 2004 042
35amp46 92 2983 8811 1111 473 9041 25986552 2668 069
35amp45 92 2983 8811 9205 5402 8491 24400791 2517 076middot
45amp36 9205 5402 8491 11109 2805 9226 33030062 3358 054
45amp46 9205 5402 8491 1111 473 9041 20935876 209 003
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
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Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 3 recording 4 29th August a998
16amp17 117 0 9381 142 0 102 26307339 2602 028~
16amp26 117 0 9381 1149 149 9132 15251888 1503 022 26amp17 1149 149 9132 142 0 102 32718227 3205 0661 26amp27 1149 149 9132 1362 15 9244 2132966 219 05~
26amp37 1149 149 9132 1363 3052 9241 26516646 2675 023 36amp26 11109 2805 9226 1149 149 9132 13723054 36amp37 11109 2805 9226 1363 3052 9241 25331157 259 0561 36amp46 11109 2805 9226 1111 473 9041 19338694 203 096 36amp47 11109 2805 9226 1348 4065 8954 26987451 2672 026 46amp37 1111 473 9041 1363 3052 9241 30341529 3007 027 46amp47 1111 473 9041 1348 4065 8954 2463066 246 om 17amp18 142 0 102 1578 0 1062 163487 1705 0 17amp28 142 0 102 157 183 9435 24867901 25 013~
17amp27 142 0 102 1362 15 9244 18709185 181 060 27amp18 1362 15 9244 1578 0 1062 29679919 2907 060 27amp28 1362 15 9244 157 183 9435 21146586 213 015 27amp37 1362 15 9244 1363 3052 9241 15520351 1504 048C 37amp38 1363 3052 9241 157 183 9435 24116011 2413 001 37amp47 1363 3052 9241 1348 4065 8954 10635027 47amp48 1348 4065 8954 1443 4222 8667 10047477 18amp19 1578 0 1062 17685 0 9786 20795627 208 OOOl
18amp28 1578 0 1062 157 183 9435 21816336 215 03H 18amp29 1578 0 1062 1767 1635 9079 29359847 288 055 28amp29 157 183 9435 1767 1635 9079 20113829 197 041 28amp19 157 183 9435 17685 0 9786 27225587 2643 079 28amp39 157 183 9435 17233 2632 9028 17773413 1702 075 39amp38 17233 2632 9028 1579 331 8675 1632955 1633 00lt 19amp29 17685 0 9786 1767 1635 9079 17813756 178 0D1 29amp39 1767 1635 9079 17233 2632 9028 1089761 1005 08l
39amp49 17233 2632 9028 1766 407 8591 15624154 1645 082 38amp49 1579 331 8675 1766 407 8591 20202861 2002 018~
)
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
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~
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0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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bullbullbull bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
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bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
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it-
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
APPENDIX 4 LANDSLIDE CLASS GUIDELINES
The following document is the official classification for landslip risk zoning in the Launceston area obtained from Mineral
Resources Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
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DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 4 Landslide class guidelines
LANDSLIP RISK ZONING - LAUNCESTON AREA 1996
The landslip risk zoning is a revision of the zoning undertaken for th Launceston area in 1974 by the Department of Mines The earlier surve extended over the whole Tamar region of some 800km2 whereas the newe version is derived from a detailed study of about 145km2 and covers the Greate Launceston area and surrounding land
The classification closely follows the former system of zonation The availabili~
of more accurate base maps combined with the collection of more detaile( surface and subsurface geological information has made it possible to refine th4 accuracy of the zoning over that produced previously Even so the zoning is stil relatively broad scale in nature but it should give a good indication of the landslip risk in most areas Locations on or near the zone boundaries may neelt more precise determination by field inspection for particular developments ir some cases The zoning is advisory in nature
As with the former survey five classes have been used in the zonation system Subclasses have been introduced in Classes IT and III on the latest maps Additional information may be obtained by reading the land stability zonatioI maps in conjunction with examination of contour information and the detaile( geological and engineering geological maps The classes are arranged ir increasing order of risk in a general sense from Class I to Class V
Class I - Generally stable ground on ~ard weathered ~rd rocks
This zone comprises areas underlain by Tertiary basalt Jurassic dolerite anI Triassic and Permian sandstone siltstone and mudstone Of these dolerite is b~ far the most common in the Launceston area
These rocks have been subject to weathering resulting in variable depths of soil loose rock and weathered rock overlying hard in situ rock Where the depth 0
weathering is shallow ie in place competent rock is say less than one metre from the surface the risk of landslip is regarded as very low In areas where weathering is deeper the risk of landslip on sloping land may be a little greate under some circumstances but is still generally low Areas with known thicke weathering profiles on these rocks (usually dolerite) have been placed in Classe Il and III depending on slope angle
Occasional small areas with deep weathering will not have been identifielt during the mapping process and such areas will have been placed in Class I Steep land with loose boulders or jointed cliff faces may present hazards fron rolling boulders or rock falls
Geological investigation and slope risk assessment at Windermere northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
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location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
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Appendix 5 Drill Logs
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bull Appendix 5 Drill Logs
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location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
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grainsize scale ct- = 1---T----1 metre structure description
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Appendix 5 Drill Logs
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Appendix 5 Drill Logs
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
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I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
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Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
~
)
Appendix 4 Landslide class guidelines
Areas underlain by these rocks are regarded as generally having very low landslip risk Steeper sloping areas should be examined to assess depth of weathering and hazards from boulders and rock falls If deeply weathered zones are located in such areas they should be treated as Classes IT and rn depending on slope angle Very rarely a higher zone may be considered
Developments in steeper areas should follow good hillside development practices
Class 11 - Generally stable ground on soft rocks deep soil on hard rocks (11a) selected reclaimed areas (lIb) all on slopes lt 7deg
This class comprises land underlain by relatively unconsolidated units of Quaternary age other more consolidated but poorly indurated units of Quaternary to Tertiary age deeply weathered hard rock areas and selected manshymade fill areas
The lowest angle on which a landslide is known to have occurred in recent times in the Tamar area is 7deg As a result land underlain by the above materials with slopes of less than 7deg is regarded as generally stable This conclusion appears to be valid for undeveloped land with a low slope angle where there are no signs of previous landslips visible and for well managed developed land of a similar nature where there is an absence of excessive loading
The 7deg slope angle has been determined using maps with a five metre contour interval and because of this interval small errors may occur on the zonation maps where steeper slopes of less than 5 metres in height are present These errors are likely to be rare as in cases where such slopes are known to occur from field observation or air photo interpretation the land has been assigned to the appropriate zonation class Small areas of land with a slope of lt7deg that could be affected by landslips on adjacent steeper slopes have been placed in a higher class
Although Quaternary estuarine and alluvial deposits of the Tamar and North Esk river valleys have been classified as Class n narrow zones adjacent to water bodies may be prone to landslip into those water bodies at some locations Some of these deposits and some selected reclaimed areas (llb) could be subject to significant settlement under load
Recommendation
Landslip risk for this class is regarded as low Excessive loading or deep excavation combined with poor drainage practices could induce unstable conditions under some circumstances Some attention should be given to these factors when development is proposed Strict adherence to building codes is recommended
Geological investigation and slope risk assessment at Windermere northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
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~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
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~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
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z~
gt~
t4
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
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Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
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Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 4 Landslide class guidelines
Class III - Potential landslip areas on softrocks deep soil overlying hard rock (IlIa) (slopes in both cases ~ 7deg)dolerite gravel areas on slopes 7-10deg (llIb) dolerite gravel areas on slopesgt 10deg (lIIc)
This class is comprised largely of land underlain by similar material to that underlying Class II areas but with a greater slope angle The land in this class exhibits no obvious signs of past movement but because of the slope angle there is some potential for landslip to develop under some circumstances Excavation and placement of fill may have obliterated old landslip features in some of the developed areas that have been placed in this class but this is not expected to be common
There is a range of risk in this zone The limited amount of subsurface information does not allow more subdivision into subclasses than indicated A small section of flatter land above and below the steeper slopes has been included in this class to act as a buffer
The landslip risk for Class ITIb (dolerite gravel on slopes -rgt-10~ is regarded as low The risk for IlIa (deep soil overlying hard rock) and IlIc (dolerite gravel on slopes gt 10~ is regarded as similar to the remainder of Class ill
Recommendation
It is recommended that a land stability assessment for land in this zone be undertaken before development proceeds This assessment will often involve a field inspection and sometimes subsurface investigations and should be undertaken by a competent geotechnical practitioner In many Class III areas it is expected that land in this class will be suitable to develop provided some precautions are taken and theseshould be oJltlined in a specific site report that deals with the development of the land These precautions Vnn usually relate to factors such as siting of the development excavations drainage and vegetation removal
Class IV - Old landslip and adjacent areas
Land in this class shows signs of definite and probable old landslip movements with no apparent movement in recent times ie there are no landslip related cracks or bare soil associated with landslip visible and long term residents are unaware of movement As well some adjacent land with similar conditions (eg geology and slope angle) has been included in this class
Geological investigation and slope risk assessment at Windermere northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
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location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
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- no we consohcicred =) I rr-~ mlts~
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- k) t)1~J
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
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bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
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Appendix 5 Drill Logs
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grainsize metre structure
I
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description
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Appendix 5 Drill Logs
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grainsize scale ICf0 ~ 1lY
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
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Figure A72 illustrates the soil classification according to the shear strength of
sediments
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Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
APPENDIX 5 DRILL CORE LOGS
Specific locations are illustrated in figure 31
Data has been derived from previous data and drill and auger hole logging
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
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location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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bullbullbull bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
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grainsize scale cm ~ I rn metre structure descriotionl
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
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it-
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
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I
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ro
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description
c6-SOrd 0 e ~
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
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1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
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~ ~
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~c=
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oo~
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gt~
t4
~ 00
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Chapter 4 Previous Work
Drill core Depth Description Moisture Classification Reference no (m) content svmbol PI 0 Top soil Unknown Leaman amp Stevenson 1972
0305 Talus of hard angular basalt boulders in basalt clay matrix became hard to dig at 19m
P2 0 Top soil Unknown Leaman amp Stevenson 1972 lt0305 Weathered basalt talus with some hard boulders too hard to dig at 305 m
P3 0 Top soil Unknown Leaman amp Stevenson 1972 0305 Talus of weathered basalt mainly clay with a few basalt boulders at 33m
P4 0 Top soil Unknown Leaman amp Stevenson 1972 03-06 Brown plastic clay gt06 Deeply weathered basalt talus with occasional boulders to 29m becoming
difficult to dig P5 0 Top soil Unknown Leaman amp Stevenson 1972
30 Brown sandy clay
60 Weathered basalt talus becoming too hard to dig at 27m P6 0 Top soil Unknown Leaman amp Stevenson 1972
3 Brown sand
9 Weathered basalt talus passing into fresh basalt rubble at 27m
P7 0-02 Dark brown dry and fractured silty clay soil some basalt boulders Stevenson 1973 02-05 Porous silty and pisolitic (iron oxide) soil 05-23 Mixture of plastic clay and basalt boulders some basalt weathered some
unweathered 23-32 Light grey-brown medium hard plastic clay fissured with shiny surfaces
P8 0-06 Dark brown clay and basalt boulders grading into dark brown soil CH Stevenson 1973 06-15 Light brown clay with basalt boulders 15-18 On north side of pit grey silty clay a thin fine even-grained quartz sand
beds some wood fragments Zones of clay extending into basalt boulder zone Other parts of pit consist of clay and basalt boulders which proved too difficult to excavate
P9 0-03 Dark brown soil and sandy silty clay dry and fractured Stevenson 1973 03-18 Hard brown plastic clay and basalt boulders Towards bottom light grey
and brown mottled silty and sandy clay with plastic clay and basalt boulders intermixed Unable to dig any deeper
PlO 0-08 Dark brown to black silty clay dry and fractured a few small basalt Stevenson 1973 fragments
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
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=
(1
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gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Chapter 4 Previous Work
08-26 Fragmental grey brown to black clay (derived from basalt) with basalt boulders occasionallimonite nodules
Pll 0-06 Dark brown crumbly soil overlying clay some basalt boulders CH Stevenson 1973 06-27 Brown plastic to fragmental clay with occasional basalt boulders shiny slip
surfaces on clay 27-31 Light grey and brown mottled clay hard plastic some thin travertine
seams Pl2 0-06 Dry fractured dark brown clay soil becoming damp towards the base CH Stevenson 1973
angular limonite fragments 06-18 Fragmental to plastic brown clay and basalt boulders 18-31 Light grey and brown mottled clay and silty clay fairly hard and massive
Iron oxide band across floor Dit above 15 mm wide carries a little water Pl3 0-05 Dry and fractured soil over light brown silty clay CH Stevenson 1973
05-15 Mainly brown a little grey fragmental to plastic hard clay some limonite 15-27 nodules
Light grey and brown mottled clay fissured Some travertine near tOD Pl4 0-06 Dark brown soil overlying pisolitic (iron oxide) clay with basalt boulders Stevenson 1973
06-15 Ligth grey brown fragmental clay with basalt boulders 15-21 Fissured grey clay with shiny slip surface on one side of pit The other part
of pit are weathered basalt debris and boulders with some moisture
P15 0-03 Dark brown soil fractured and dry occasional basalt boulders CH Stevenson 1973 03-09 Basalt derived light brown fragmental material with large basalt boulders 09-17 Fine even grained brown sand (mainly quartz) 17 Blue clay
B I 0-05 Clay - highly plastic dark brown Some organic in top half (soil amp subsoil) M=PI CH Moore 1986 05-19 Clay - highly plastic grey (Launceston Beds) MltPl CH 19-44 Clay - highly plastic brown MltPl CH 44-50 Soft zone M=Pl CH
B2 0-02 Clay - Organic black highly plastic (soil) M=Pl OH Moore 1986 02-04 Clay - highly plastic dark brown (subsoil) MltPl CH 04-60 Clay - hi~hly plastic brown (Launceston Beds) MltPl CH
B3 0-02 Clay - Organic black highly plastic (soil) M OH Moore 1986 02-15 Clay - Highly plastic yellow (yellow clay) M=Pl CH 15-30 Clay - Highly plastic brown with ironstone grit (Launceston Beds) MltPl CH 30-33 Clay - Highly plastic grey 33-60 Clay - Hi~hly plastic brown
GeoloRical investigation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
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project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
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lE rear ete I (~ OCll tI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
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description
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Appendix 5 Drill Logs
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grainsize scale ICf0 ~ 1lY
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
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Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Chapter 4 Previous Work
B4 0-08 Gravel amp organic clay - Gravel coarse road base coarse Clay black organic GCampOH Moore 1986 08-16 Clay - Highly plastic yellow-brown M=PI CH 16-18 Clay with gravel- clay highly plastic yellow Gravel coarse quartz pebbles MltPI GC
10 B5 0-10 Gravel- coarse poorly sorted Road base coarse with some clay (Fill) GC Moore 1986
10-12 Silt - Organic fine low plasticity (Soil layer) M OL 12-15 Clay - High plasticity brown (Clay interbedded with gravel) M=PI CH 15-20 Clay with gravel- coarse gravel clay highly plastic MltPI GC 20-27 Clay highly plastic brown MltPI CH 27-33 Clay with gravel - clay highly plastic brown Gravel coarse GC
B6 0-15 Gravel and clay - Gravel coarse clay highly plastic grey-brown M=PI GC Moore 1986 15-25 Clay highly plastic liJzht brown D CH
B7 0-03 Clay - organic with roots dark brown (Topsoil) M OH Moore 1988 03-42 Clay - highly plastic orange (Launceston Beds) CH
B8 0-04 Clay - black organic with roots D OH Moore 1988 04-10 Clay - orange highly plastic M 10-25 Clay with gravel- brown clay highly plastic gravel fine ironstone 1-2 M CH
mm 10 25-40 Clay - Orange highly plastic M CH
B9 0-09 Clay - Brown organic highly plastic D OH Moore 1988 09-16 Clay - brown highly plastic M CH 16-19 Clay - Rubbly ironstone band M 16-34 Clay - brown highly plastic M CH 34 Clay with pebbles M
BIO 0-08 Clay pebbles Clay- orange brown highly plastic Pebbles basaltgt 3 mm CH Moore 1988 ironstone lt 1mm M
08-34 Clay - brown highly plastic gradual change in colour with depth M CH 34-7 Clay - orange highly plastic H
Bll 0-02 Concrete and gravel G Moore 1988 02-10 Clay - brown highly plastic M CH 10-31 Clay - orange highly plastic M
B 12 0-02 Light brown loamy silt Ingles 1991 02-45 Strongly bleached silt with abundant ironstones to 5cm 04-55 Very dry clay with yellow brown grey mottle
BB 0-015 Light brown loamy silt Ingles 1991 015-5 Stiff dry clay mottled yellow grey
GeoloRical investiRation and slope risk assessment at Windermere northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
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I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
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location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
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core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
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- k) t)1~J
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
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FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
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description
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Chapter 4 Previous Work
Borehole 14 0-023 23-5 05-55
Borehole 15 0-025 025-5 05-65
Borehole 16 0-20
Borehole 17 0-07 07-18
Borehole 18 0-05 05-19
Light brown silt Mildly bleached ironstone rich silt Dry mottled clay Light brown loamy silt Mildly bleached ironstone rich silt Very dry clay mottled yellowlbrown Fairly uniform clay very dry with well rounded boulders to 30 cm and brownyellow orange mottle Light brown silty gravelly loam Clay - Mottled redloranpe2fey very dry Light brown silty gravelly loam Clay slickensided strongly mottled yellow grey (latter predominates) somewhat porous and also layered
Ingles 1991
Ingles 1991
CM Ingles 1991
Ingles 1991 CH CM Ingles 1991 CH
Geololical investilation and slooe risk assessment at Windermere northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
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Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
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- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
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- k) t)1~J
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lE rear ete I (~ OCll tI
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
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bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
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FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
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~~
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Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
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bull A(~
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w~tIe~cJ tbDR
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6 6shyLl~ A j fl~
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
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bA6 6 f1
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I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
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Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
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) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
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ro
project location logged by
description
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~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
-- -
bullbullbull
bullbullbull
bullbullbull bullbull bull bullbullbull
bullbullbull
I ~
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
1amp Amiddot 4 A
~ -AIJJ~ lIl pound
bull ~~ LLtY I
61J6 6A
6Al IJ ~
A b A Akh Ashy
llb-A
Qn
~I
~II
~
shy~
bull5
iIIo ~nu(
Ix)~lJo( bullbull~
Ibullbullbullshy1-bullbull
I~o -I ~
~-bj ~bullbull
0
project IJI~r~re area hole no wot1 (gW-l)
location~avn+slilll page lof z logged bY~ele (YbcdCflpoundild date cxctmiddot I If
scale I ~ 11YI
descriptionl
fuSJu- (oulo~
~Ild ~Ir ~ COOrSE ~rCIVleC1 peldspov rlc~
- frQSh roc~middot
core CS5 -prota6lIj sand lICy IQjelS
oQnltje d~~ - orgoc IroterlOI pYe~Ent-
- no we consohcicred =) I rr-~ mlts~
legtroUJn Ca~ NOre COolldoreo va-~ pne gOlled
Eandnch ta~eV doY- In cdovV dlDStrDtes Cl dQ~ sedtNOV~~
- k) t)1~J
gre~ coIou I vJC1 tIacl Umiddot
~ 00ve CbOrs~uC I nclrI o~on f c
o-ectlutYl orOtPr1 i~ovJ ctyenffClCQ
lE rear ete I (~ OCll tI
VU~ darlfbrown del) (e-lll4l4-r)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
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bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
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=
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t4
gt
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t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
bullbullbullbullbullbull bullbullbull
bullbull
bullbullbull
bullbullbull bullbullbull
bullbullbull
bullbullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project NrOe~lYqe 0 ~a hole no WD~ (fgtlt1) 10cationGtonr-gt ltt 11 page20f logged by RcxYelle )tcdC)VA(d date ZCl Cf8
grainsize scale I rn metre structure descriptio
~3 bullbullbull bullbull0
)()C)CIx)lt~b~
FY- j
~ Cool seam - b Cc( ocl0 e loJelf -1c 11- leKo
~~shy~O
Aa
~)(~
~ ~J
~ ~~
) lamiddotlDtIII ~ j vc wet- oreel ~ bullbull411
~= ~
1-gtltshy
~~~bullbull ~bullbullbull~~1-shyla
ebull bullbullt ~
~
ILLI Ibullbull ~
~~
~
~
middot1~
~~
~
~l J
Geological Investigation and slope risk assessment at Windermere northem Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
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1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
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fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
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lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
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bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
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grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
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Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
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MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
bullbullbull bullbullbull
bullbull bullbull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project I-Ilrcterm~r~ anQ hole no ~tt1 Cpounda+t1-) location ~ne ttl page3of3 logged by ~~ IYtAccXgtrold date ~q I cri
grainsize scale I I metre structure description
~ a6 Itmiddotmiddot~
ID) ~J lIe~ hgnt- (YCtQnQ C-reorY w-l-e IV) coloo Y
MAe 3tOmed sordt --I
bull
bull br-ovJt1 dQ~iili _ -__-_- ~ ------_ --- - _ _--- ------ bull ----_ -shy
IX ~ ~ bull doy k br-own co~
le )C)C L4eot1erQd b(ut
~ oo~~ ~lt ccl~
roso- (IlShJ )Ab ~
AA ~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
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+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
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~c=
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oo~
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z~
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t4
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
bull Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project WlnceffYeye OftCl hole no fH2shy
location COrn e~lCltcil sov~ page of logged by ~~ mudmJd date 21 S lamp
grainsize scale cm ~ I rn metre structure descriotionl
~ bullbull bOat+C so I ~ (OOTS 4 j A ~r~~I g(adeS Igtft) ~~-PSgtocl ~f
I - wlaquo td c-ts A A A -~~~bull z 11 =lJtc ~SGllJQ -gtOIOflCJq ~le1 Pf~1~OPnto rlt-tL A 11
A A ~ feldspor p~ltXrj~-o(Q eude-r I I-ctYd sp~c-~
l
Hs ~1~d1orgt IUPQ
A h u I- ~
A Bolld bosoI+ tQSS we C1tv1e (ed -tVo -the olQell)Q Ipound A A
bull A(~
~ill amp-
w~tIe~cJ tbDR
b b 0 laquo
II A1JA J q AJ e A t J 10 A f
6 D J 11 )
11 A A A A
pound l1 C1 A 1
L1 tJ 6 A A AA~
1lt b d I4 A A
A f D l t1
11 b
bull JtJll 11 1 A~iJ A
6 6shyLl~ A j fl~
~ l) d L A l~a
L1 Jl n~A
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
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~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project -)nOQ-(TQle oIeD hole no ~~Z
location lbOrn ee~ S Ittll page of ~ __-1logged by ~le ~ date 2 - ego -9 ~
grainsize scale ct- = 1---T----1 metre structure description
A~6
2JJ D6 I1All
- 2S L1i
A Cgt ~
At LlAll
At
bA6 6 f1
l) D A AA D~6
~ A ~
6 e U A ~
A ~ e b t D Cbn+ac-l- o~ TeVhOVj Q~cI I- ~~ 1 conltje lf I-----+----+-b-=-D--t--II-----I -lev nc~ amp~~ I CY1Q Wts
I--_+- -+--A~A----+---t bull s 310 r IJ bCtlc~d ~ ha1 seurod I fY(L-+3 A c A _ pIne qtollltiC1 blcctt (Thrl ~chOlo-)~A J I bull
~u A A Do - Ve ~ I-coc f20e 4c -the oJollt +0 ~~ J ~~
ltlt ~1b llltlo IS Sc~l-ch czeA A
Cl lJelu ~1Il CtrO~ q-lltllOroWV CCl~ =~~r L LI 7] -L-~ ~ Ji J ~ DleCsr-C cIcA- ~ole- ~ laquo 0
J bull ~
fgtrown cJo~ 1tP1- cornlrotes rnvcV-o or- the ovtO
IlIlno t7eddj ap(9=Ltenl-
it-
Ii~
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
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0
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~
~ ~
~
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00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
bullbullbull
bullbullbullbull bull
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project hole no location page of logged by date
grainsize scale metre structure description
Llb
C1J
~
Sand I C~ev - ~nt- brown - (U cOQlselj ~oned 11-cn tHl
Claj btAl- SOllAlt ClMOV op- elcI) aNt
MIeeeC - f-Ite SQnd
J)
0 - SrOtD clo)j o bull
1_ - fyena2 COr1 So Cat-ed
Obullbullbullbull
~ Ac
fih
b1shy
) Geological Investigation and slope risk assessment at Windermere northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
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t4
~ 00
0 e ~
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~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
)
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG
grainsize metre structure
I
Efl
ro
project location logged by
description
c6-SOrd 0 e ~
hole noBt2 page4-0f5 date scale
)
xshy
~
~~lalol
+k1lclt~k cl ~ ~ev
lA- LAv1e MYJ ~J
to ~CDClaquo
o laquo
Srd ~Jo
~
bull Geological Investigation and slope risk assessment at Windermere northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 5 Drill Logs
DIAMOND DRILLCORE LOG project Wde(Mlf~ o~ hole no ~tt Z location Lo Q- l Scwtlh oh 11 pag~of sshylogged by - nb~ d date 21 ~ - 9 ~
grainsize scale ICf0 ~ 1lY
metre structure descriptio~
ltb
I
q~ sonO IQt~ OltOoneln~ Wlf-1- OfjO-tIIC lQr1 ftat1ef
1e1lo-a ~ colov (h~r-o)
v ~ ~ efd or- ~ole Cl)
Geological Investigation and slope risk assessment at Windermere northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
bullbull
(1
0
~
~
~ ~
~
~
~
~c=
gt~
oo~
~z
z~
gt~
t4
~ 00
0 e ~
(1
~
00
gt
~
~ ~
Slt
=
(1
t4
gt
~ gt
~
t4 ~
0
0
~
00
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
MINERAL RESOURCES TASMANIA
Client R Macdonald
Sample Location Windermere
Soil Mechanics Testing Whole Sample X-Ray Diffraction Analyses (Approx Wt )
Sample ECN LL PL LS 0 (0) c (kPa) Quartz Kaolinite Smectite K-Feldspar Mica Goethite Gibbsite
S11 1 89 32 19 25 60 10 2 2
S12 2 66 21 18 35 25 20 10 2 5
S14 2 101 30 22 30 40 20 2 2 2
S22 1 83 29 18 10 3 20 65 10 2 2 2
S23 1 67 23 17 40 40 10 5 2 2
S24 1 56 20 15 45 35 10 5 2 2
S25 1 64 21 16 40 30 10 10 5 2
S26 1 73 25 17 40 35 15 5 5 2
S41 6 132 28 26 30 55 5 5
S42 6 129 26 27 30 50 5 10
Atterberg Limits tests performed without pre-drying samples Minerals present in trace amounts or amorphous minerals may not be detected
ECN = Emerson Class Number Peak overlap may interfere with identifications (eg K-Feldspar may mask the
LL =Liquid Limit presence of Rutile Goethite may mask the presence of Hematite large
PL =Plastic Limit amounts of Kaolinite may mask the presence of small amounts of IImenite)
LS =Linear Shrinkage Major Goethite peak in S41 and S42 occurs at 417A-416A (normal Goethite
0 =Residual Angle of Internal Friction 4183A) - may indicate some replacement of Fe by AI
c =Residual Cohesion Smectite content in S11 and S22 rounded-down to 10
Smectite content in S23 S24 S25 rounded-up to 10
Smectite content in S26 rounded-up to 15
ftttJ~ Analyst Richie N Woolley
Date 24 September 1998
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
I 0 0 OIOVALUE 1 51 90 5ITTw LHIAl I 8420 44 15 22 I Omiddot 0 O 100 0
Tsct TTw LHIA6 I 8 70122 48 16 231 0 102 0 Tsct I 0 0 I bull QI 01 5 95i 2 0 0 5 I I 0 01 I 01 17 Omiddot 0 0 00
Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
91281 11 23 61 I 401 55 5 i 2 2 47 I 51 40 0 55middot 102~ OSO i 0 0 01 2 0 01 01Os T Ui97A3 3 01 00 1122128 831261 I 25 80 15 21 0 42 15 27 80 50 102 045
TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
TsC lH98A2 21 123132 81251 5 25 5 85 5 0 30 51 25 i 701 701 100 085
I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
_r
I I - I I i I I
I I i I I I i 1 --J--- ciW I I I
I PI d~1h 11 01 Plndls mco c davt~ k~s-Gaz SMEC MOl HAllO LEPlO GOEr GIBS ZEO MICA KmiddotF PLAG FELO total old middottoIII nongtlt PYRX AMPHlotal Fo 100I901 cmiddotsmelc-kaollc-lWldcooc-oltgtbc-llOmcaoMlaK+s kH+S iTbllll
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Os T LHI7A2 2 0s7 Tl LHI7Al 0 I
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TsC LHIIAI I 01 I I 0 Tl TIs Uil7AS 6
lE 01 0 0 0 01 01 00
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I I 01 0 01 0 I 0 01 00LH96A5 5 11227 85 26 0 TsC Ui96A8 8 101 301 71 24 01 0 01 0 I 0 0 01 00 TsC
30 10 55 5 2 01 37 5 32 85 851 102 080 11530 85 24 E 30 5 55 5 2 2 2 31 0 32 i 80 801 lIl1 080
T lOUlSwoal LHt9AI 1 11331 6225 6
T iOUlSwoat LHt9A3 3 T T_ lH9MS 4 104 321 7222 01 0 0 2 01 01 0 010
0 E 5 01 5 0 0 0 0 5 00
T 10s1 iLH100A3 3_13916 21 10 I 80 35 2 2 41 84 0 80 I 01 35 891 035
To UilOOA5 5 105128 7623 01 0 0 4 0 0 0 00
T LHl00Al 1 i
01 0 0 0 I 0 0 01 00
Ts I LHIOIA3 3 4716 28 12 0 0 0 0 0 0 01 00 IUiIOIA6 6 11627 68 24 E 35 0 45 2 5 2 21 44 0 40 55 55 89 OSS
T LHl01AI 1 0 E 1
T UiIOIA6 9 8520 45 17 E 0 0 0 2 I I 0 0 0 010
IT T LHI02AI I 0 5 0 0 0 0 0 0 0 00
T LHI02A2 2 44 21 2311 E 0 010I 0 0 0 0 01 0
IT UiI02A3 3 I 0 i 80 35 5 5 65 0 80
I 01 35 1001 035
T Ui02AS 5 lOO 26 83 231 16 2 35 SI SS 2 5 5 42 0 42 I 80 80 1021 080 0 0 0 5 0 01 0 010
IT T LHI02A6 6 8722 6522
Qlb LH103AI I I 0 E 0 0 0 0 1 I 0 0 01 00
T LH103A2 2 174 371 137 27 E 0 0 0 0 I 0 0 01 00
T 0lIgt LHI04AI I I 0 E 0 0 0 0 I 01 01 01 00 T 0lIgt Uil04A2 2 0 E O 0 0 0 0 0 01 010
T Qlb LH105AI I 161 381 121 25 5 0 0 0 0 0 0 0 00 Ts OIl LHl0SA3 3 161 311 130 28 E 20 15 80 5 2 01 27 0 22 I 75 75 102 075
T LHIOIlA2 2 133 351 8623 E IS 5 80 01 IS 0 15 I 851 85 1001 085 T LH10SA3 3 110134 76221 2 90 5 2 0 8 5 2 901 90 191 0185
UiIOllM 4 144137 107 26 E 11 3 lOO 2 01 2 2 0 1001 001 102 086 --Ts Ts I LHIOIlA5 5 128133 86 24 01 0 0 0 I 01 0 01 00I I I 10 2 85 21 01 12 2 10 I 67 67 191 085Ts Uil06A7 7 05 321 7318 I I 01 0 0 0 I 01 01 00
Os I LH107AI 1 shyT LHI06A6 8 0 0
0 E I 01 0 0 0 0 01 01 00
LHI07A2 2 45 211 2410 E I 65 25 5 5 2 71 n 0 70 0 251 102 0125Os I 0 0 0 7 1 0 0 0 00Os LHI07A3 3 0 0 0 0 0 0 0 0 010
Os LHI07A6 8 Os I LHI07AS 5 35 18 17 4 E I
0 I I 01 0 0 0 0 0 0 00
CJ LHI08A2 2 119261 9327 E I 0 0 01 0 I 0 0 0 010
CJ LHI06A3 3 52119 3314 i o 0 0 0 I 01 0 01 010
CJ LH106A4I 4 I 0 01 0 0 0 I 0 0 0 010
LHI08AI 1 I I 0 E I 0 0 0 0 I 0 0 0 00Os LHI09A2 2 0 lE I 0 0 0 000 0 0 0
~ lBE I 0 0 0 0 I 0 0 0 010Os T LHI09A3 3 53 17 36114 0 120 E I I I i 01 0 0 0 I 01 0 01 00
10s7 Ts LHI08A7 71 2Si22 3 2 511E I 01 0 0 0 0 0 0 010
Os T
Os Ts LHI09AS
LHI09A9 I 01 28E I I I 01 01 0 0 I 01 0 0 00 I 0 01 01 01 I I 01 01 0 00Ts ITsbck IUi09AO I 101 bullbull 0 I I
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 7 Shear box tests
The shear box test
The test consists of a brass box split horizontally at the centre of the soil specimen
(illustrated in figure A71) where the soil is gripped by metal grilles A vertical load is
applied to the top of the sample by means of weights As the shear plane is predominately
in the horizontal direction the vertical load is also the normal load on the plane of failure
Having applied the required vertical load a shearing force is gradually exerted on the box
usually from a proving ring - annular steel ring that has been carefully machined and
balanced When a load is applied to such a ring a deflection will take place that can be
measured on a dial gauge enabling the causative force to be obtained from the ring
calibration supplied by the manufacturer
Normal load
Shear force 1 ( _~_~ c~porous disc
I~ Shear force porousdisc
halfmiddot of box
Figure A71 Diagrammatic sketch of the shear box apparatus
A second dial gangue (fixed to the shear box) is used to determine the strain of the test
sample At any point during the shear the proving ring reading is taken at fixed strain
intervals (strain =movement of box length of box) and failure of the soil specimen is
indicated by a sudden drop in the magnitude of the proving ring reading or a levelling off
in successive readings
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 7 Shear box tests
6~~
6(~
T=C~~
C1n tI 11 ~
c-O or _ soil tJ=O or c soil If
c- tJ bull
soil
Figure A72 illustrates the soil classification according to the shear strength of
sediments
1shy
Geological interpretation and slope risk assessment at Windermere northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
)
APPENDIX 8 DESCRIPTIONS OF SLOPE STABILITY MODELS USED
Bishops Simplified Method
Cousins Method of Tables
Galena
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 8 Slope stability models
Bishops Simplified Method
Bishops Simplified Method is a simplistic means of calculating the stability of slopes in
terms if the factor of safety (Fs) The model uses a number of in parameters (equation
A81) which are applied to circular slip failure planes This model is renown for )
producing realistic results and it is relatively easy to calculate
Fs =L[cb + W (l-r) tanep] (lm) LW sina bullbullbullbullbullbullbullbullbullbullbullbullbullequation ASl
Where r - pore pressure t - Shear stress lt1gt - Residual angle of internal friction c - Cohesion W - sediment weight a - angle between the slope and the normal
Cousins Stability Charts
Cousins through extensive computer analysis has identified that specific average pore
pressure ratios relate to a slope angle I and a stability number Nf where r =YfWh This
method depicts the relationship between slope angle and the co-ordinates of the critical
slip circle for a number of pore pressure ratios Such a relationship can be derived from
the tables illustrated in figure A81 providing the correct input parameters are available
From this the stability number or factor of safety can be derived
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Appendix 8 Slope stability models
3~ Toe circles Toe circles Toe circles shy200 f--I-- ~
~
~
~ 1~ ~~-- ~~~-= ~ A 50
~
~ 98 ~G
ltl~ 0 Jbullbull 50 ~ 8 50 E 50 ~ lt
20 Ace so~ 40 -gt~~s ~ 30 15 20
~ ~ --l~Q 20 IS ~ l6 10 20 -=shyrJ) I 6 I 5111
lid -=2 3 ~~~~+
f--~ - 2 2--B -~~
7 - I I 6
50 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 35 40 45
Slope i (degrees) Slope i (degrees) Slope i (degrees)
la) (b) (c)
Figure ASl Stability numbers for toe circles (a) r =0 b) r =025 c) r =05
(Cernica 1995)
Galena Slope Stability Analysis System
Galena is a computerised slope stability-modelling package which incorporates three
methods of calculating slope stability Bishops Simplified Method Spenser-Wrigth and
Samara Method The model used is depends on the type of failure plane Le if failure is
circular or non circular This model is user friendly and produces results rapidly The
model enables failure surface to be defined in terms of the actual slope rather than as
abstract point in space (Galena 1998)
Geological interpretation and slope risk assessment at Windermere northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
Rochelle Macdonald Geological investication slope risk assessment at Windermere northern Tasmania Honours 1998
Field B9lt~~~r1 B~~~gescription AMG Nortt AMG Easti f9sition________________ _ 137813 23 dql~~i~~ __ t1g~Iy_~~atheredsiqLeri~_~9u_Ici~~~ __ ____ __ _ __ ___ ___54~sect~~Q~~~q I gnr ~ I~1Cl~ l--li9f1w~y L_os Jtl9E3 lqs_Rd 137814 37 claystone Alternating clay and sand layers subhorizontal bedding 5426652 501550 property no 1416
________________~_+-_L~~+________~-c----____~------c----~~~~~~-----+__~~___1~~~__+_=___c_----~____~~_______=_---------------
___ 1_3_78~1~ 21 basalt Weathered basalt clast 5427230 500960 Cliff on top of Gaunts Hill _ 137816 35 basalt Contact between Tertiary basalt and Tertiary sediments 5426652 501550 top Gaunts Hill property no 1416
______~ --- ----+-~~~_+______~__c_~_____~------c-------~~~~----~~~~_+___=_~~+_~_____~+__--~~~-----~---~~~--
137817 22~~~_~____ Hi9hly weathered basalt boulders 542Y~1- 5011~QE~9E~rtYI_o~Jj1_ _ _ _ __ __13_~_~ _box__t--e_st--ing--------__~_+-5=_4_27c_4-=-60=+____5=_=0__0__72=_5=-+p-roop__e-rt-y-=-n__o- ~ _-=6~7-+=-clc=aLys=-=t_=_one~T=h__e=--re--s--u_lta-n--t_blo=_c--k___a--ft-=-er__s_h_e-a--r 14-1--7~
137819 34 basalt Thin section of Tertiary basalt capping Gaunts Hill 5427215 501150 Gaunts Landslides _--~~ -------------+=-=-----+=-~-----_____~____~______~~_____~~~--__t____=__=_=~=+_____==__==_J_~~___=__~_______---- ~--~--------
137820 36 basalt Thin section throuQh Tertiary basalt boulder 5426652 501550 Proppertv no 1416
Tertiary Jurassic Appendix 8 137813-137820
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
REFERENCES
Barlow MH amp Newton RG (1975) Patterns andprocesses in mans physical environment McGraw-Hill Sydney 250 p
Baillie etal (1987) Late Cambrian to Devonian In Burrett CF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15
Bell FG (1992) Engineering properties ofsoils and rocks third ed ButterworthshyHeinemann 345p
Berkman DA (1976) Field Geologists Manual The Australian Institute of Mining and Metallurgy Australia 295pp
Blatt et al (1980) Origin ofsedimentary rocks Prentice - Hall Inc New Jersey 783p
Bryant EA (1993) Natural Hazards Cambridge University Press New York pp 236shy256
) Bureau ofMeteorology (1998) Climatic records Acacia House Commonwealth of Australia Bureau ofMeteorology
Burrough PA (1986) Principals of geographic information systems for land resource assessments Monographs on Soil and Resources Survey 12 194p
Carson M amp Kirby M (1972) Hillslope processes Cambridge Uni Press London 260pp
Cernica IN (1995) Geotechnical Engineering Soil Mechanics John Wiley amp Sons Inc Brisbane 449p
Clarke GM (1986) Debris slide amp Debris Flow Historical Events in the Appalachians South of the Glacial Border in Costa lE amp Wieczorek GF editors Debris FlowsAvalanches process recognition and mitigation Geol Soc America Rev Eng Geology 7 pp 125-137
Direen NG (1995) Geophysical Modelling ofthe Longford Basin Honours thesis University of Tasmania
Donaldson RC (1991) Rosetta Landslide Geological investigation and slope risk assessment Dept ofMines and Mineral Resources Tasmania Report 199120 80pp
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Eckel (1958) Landslides and engineering practice National Academy ofScience Special report 29 232 p
Elmer S (1971) Slope stability at Windermere Unpublished Tasmanian Mines Department Report 197110
Forsythe SM (1989) Late Carboniferous - Triassic In Burrett eF and Martin EL (eds) Geology and Mineral Resources of Tasmania Geological Society of Australia Special Pub 15309-333
Forsythe SM (1996) Land stability zonation map Launceston Area Urban Engineering Geology Series Tasmanian Geological Survey
Galena Slope stability model online httpwwwrockwarecomcataloglgalena
Gerrard1 (1992) Soil Geomorphology An Integration ofPedology and Geomorphology Chapman and Hall Great Britain 269p
Graham J (1964) Mechanisms ofsoil stabilisation CSIRO Pub Melbourne D5-1 to D5-30
Gray et al (1974) Complex history of Badger Head area Northern Tasmania Aust 1 Earth Sci vo140(2) 155-168
Gulline (197381) Frankfort sheet Geological Survey ExplanatoryReport Geological Atlas 1 mile series zone 7 sheet 38 (8215s) Tasmanian Department ofMines
Gulline AB (1981) Frankford Sheet Geological Survey Explanatory Report Tasmanian Department ofMines zone 7 sheet 38 (8215s) 25pp
Habib P (1983) Soil and rock mechanics Cambridge University Press London 135 p
Hail 1R (1977) Applied Geomorphology Elsevier Scientific Publishing Company pp 157-181
Haneberg We (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886shy892
Heath R (1997) Geotechnical risk assessment ofthe Claremont area Hobart Tasmania Honours Thesis 92pp
Herbert (1982) in Haneberg WC (1991) Pore pressure diffusion and the hydrological response of nearly saturated thin landslide deposits to rainfall Journal ofGeology vol 99 pp 886-892
Hutchinson JN (1967) The free degradation of conference on shear strength
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
properties of natural soils and rocks Norwegian Geotec Institute vol 1 113 shy118
Ingles aG (1991) Land stability Windermere Farm East Tamar Technical report for T Hodgman Unisearch Limited
Iverson RM amp Major 1J (1986) Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilisation Water Resources Research vol 22 no 11 pp 1543-1548
Iverson RM amp Major J1 (1987) Rainfall ground-water flow and seasonal movement at Minor Creek landslide Geological Society ofAmerica Bulletin vol 99 pp579shy
- 594
Keefer et al (1987) Real-Time Landslide Warning During Heavy Rainfall Science vol 238 pp 921-925
Keller EA (1992) Environmental Geology 6th ed Macmillian Publishing Corp New York pp 48-55
Knight CJ (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197191
Knight CJ amp Matthews WL (1976) A Landslip Study in Tertiary Sediments Northern Tasmania Bulletin ofthe Association ofEngineering Geology 14 pp 17-22
Leaman et al (1973) Gravity Survey of the Tamar Region Northern Tasmania Tasmanian Department ofMines Geological Survey Paper no 1
Leaman DL amp Stevenson PC (1972) Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 197223
Leopold et al (1964) Fluvial processes in geomorphology Freeman San Francisco 280pp
Longman MT (19646) Explanatory Report of the Launceston Quadrangle 1 mile Geology map series (K55-739) Tasmanian Department ofMines
Longman MT amp DE Leaman (1968) Gravity Survey of the Tertiary Basin in Northern Tasmania Tasmanian Department ofMines Geological Survey Bulletin no 51
Londe P (1973) The role of rock mechanics in the reconnaissance of rock foundations water seepages in rock slopes and the analysis of the stability of rock slopes J Eng Geology vol 5 pp 57-127
Lowe J (1966) Stability andperformance ofslopes and embankments American Society ofAvile Engineering pp 1-35
Geological IfIVestigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
I
References
Luck DP (1997) Site classification report for Payne s property Consulting Engineers Report D P Luck and Associates
Lupini et al (1981) The strained residual strength of cohesive soils Geotechnique 31 no 2 p 181 - 213
Matthews WL (1976) Test pits on R Ambroses property at Windermere Unpublished Tasmanian Mines Department Report 197632
MarshalI TJ Holmes lW amp Rose CW (1996) Soil Physics 3rd ed Cambridge Uni Press USA 450 pp
~Clenagan amp BailIie (1975) Geological Survey Explanatory Report Geo atlas 125000 series sheet sk-554 Launceston Tasmanian Department ofMines
MitchelI lK (1976) Series in soil engineering John WilIey and Sons New York 422p
Moon A (1984) Investigation ofBovilis Landslide near Devonport Masters thesis University ofTasmania 66p
Moore WR (1981) Slope Stability of Lot 1 Adams Subdivision Windermere Unpublished Tasmanian Mines Department Report 198152
Moore WR (1982a) Slope Stability Investigation of Archers proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198222
Moore WR (1982b) Slope Stability Investigation of a Proposed Subdivision at Windermere Unpublished Tasmanian Mines Department Report 198288
Moore WR (1985) Propose House Site 3 High Level Block Ambroses Subdivision Windermere council recommendations Tasmanian Department ofMines
Moore WR (1986) Investigation of Cracking Picketts House Windermere Road Windermere Unpublished Tasmanian Mines Department Report 198683
Moore WR (1988) Investigation of cracked house on Windermere Road East Tamar Unpublished Tasmanian Mines Department Report 198821
Montgomery CW (1997) Environmental Geology 5th ed WCB McGraw-HilI New York pp 171-191
Murch et al (1995) Environmental Geology John WilIey amp sons Inc New York pp 145-160
Partion et al (1974) General report on mass movements r International Congress of the International Association ofEngineering Geologists Sao Paulo Brazil Proceedings Vol 2
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
Reid ME (1994) A Pore Pressure Diffusion Model for estimating landslide-influencing rainfall The Journal ofGeology vol 102 pp 709-717
Ritter DF (1986) Process Geomorphology 2nd ed Southern Illinois Uni Carbondale
Sama SK (1979) Stability analysis of embankments and slopes ASCE geotechnique vol 23 4 pp 423-433
Schmidt et al (1995) Limits to Relief Science vol 270 pp 921-925
Skempton AW (1964) Long-term stability of slopes Geotechnique vol 14 no 277shy101
Smith GN (1971) Elements ofsoil mechanics for Civil and Mining Engineers 2nd ed Crosby and Lockworld London
Stevenson Pe (1973) Stability of Land at Windermere East Tamar Unpublished Tasmanian Mines Department Report 197391
Stevenson Pe amp Sloan DJ (1980) The evolution of a risk-zoning system for landslide areas in Tasmania Australia In Webster lA (convenor) The third Aust- NZ conference on geomechanics vol 2 Proceedings of Tech Groups - NZ Institute of Engineers Wellington NZ 6 (1) 273-279
Sutherland FL (1971) The Geology and Petrology of the Tertiary Volcanic rocks of the Tamar Trough Northern Tasmania Rec Q Vie Mus 36 58pp
Telfer AL (1988) Landslides and landuse planning Tasmanian Dept of Mines Geological Survey Bulletin 63 62p
Terlien MTJ (1996) Modelling Spatial and Temporal Variations in Rainfall-Triggered landslides ITC Publications no 32 ITC Enschede 254 p
Terlien MTJ (1997) Hydrological landslide triggering in ash-covered slopes of Manizales (Colombia) Geomorphology 20 pp 165-175
Terzaghi K (1950) Mechanism of landslides in application of geology to engineering practice Geol Soc Am Berkey Volume
Ulrich T (1987) Stability of rock protection on slopes Journal ofHydraulic Engineering vol 113 pp 879-891
Walker etal (1985) Geotechnical Risk associated with hill side development Aust Geomech News vol 10 pp 29-35
Walker B amp Fell R (1987) Soil slope stability instability and stabilisation AA Balkema Pub Netherlands 440 p
Walker MB (1991) Chambers science and technology dictionary W amp R Chambers
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania
References
New York pp 35
Wells PM (1988) Palynology of Tertiary sediments from Windermere Drill holes 1 amp 3 Tasmanian Department of Mines Unpublished Tasmanian Mines Department Report J98805
Wu et aI Risk of landslides in shallow soils and its relation to clear cutting in SE Alaska Forest Science Vol26 p 495-510
Yong RN amp Selig ET (1980) Application of plasticity and generalised stress-strain in Geotechnical engineering American Soc Civil Eng New York 351 p
Young A (1977) Slopes I amp A Constable Ltd Great Britain 288p
0shy
~-
Geological Investigation and Slope Risk Assessment at Windermere Northern Tasmania