REPORT NO: 6604-4 GEOTECHNICAL INVESTIGATION …

HOGGAN ENGINEERING & TESTING (1980) LTD.

REPORT NO: 6604-4

______________________________________________________________________________

GEOTECHNICAL INVESTIGATION

PROPOSED DRAYTON VALLEY AQUATIC CENTRE

NEAR 5749 – 45 AVENUE

DRAYTON VALLEY, ALBERTA

______________________________________________________________________________

______________________________________________________________________________

OCTOBER 2019 Hoggan Engineering & Testing (1980) Ltd.

17505 – 106th

Avenue

Edmonton, Alberta

T5S 1E7

PHONE: 780-489-0990

FAX: 780-489-0800

______________________________________________________________________________


ii

REPORT NO: 6604-4

GEOTECHNICAL INVESTIGATION

PROPOSED DRAYTON VALLEY AQUATIC CENTRE

NEAR 5749 – 45 AVENUE

DRAYTON VALLEY, ALBERTA

TABLE OF CONTENTS

1.0 INTRODUCTION ...............................................................................................................1

2.0 SITE AND PROJECT DESCRIPTION...............................................................................1

3.0 FIELD INVESTIGATION ..................................................................................................2

4.0 LABORATORY TESTING.................................................................................................3

5.0 SOIL CONDITIONS ...........................................................................................................3

6.0 GROUNDWATER CONDITIONS .....................................................................................4

7.0 RECOMMENDATIONS .....................................................................................................4

7.1 Footings....................................................................................................................4

7.2 Cast-In-Place Piles ...................................................................................................6

7.3 Seismic .....................................................................................................................9

7.4 Building Excavation.................................................................................................9

7.5 Slab-on-Grade ........................................................................................................11

7.6 Surface Utilities .....................................................................................................14

7.7 Cement ...................................................................................................................16

8.0 CLOSURE .........................................................................................................................17


G E O T E C H N I C A L I N V E S T I G A T I O N

PROJECT: Proposed Drayton Valley Aquatic Centre

LOCATION: Near 5749 – 45 Avenue

Drayton Valley, Alberta

CLIENT: Town of Drayton Valley

5120 – 52nd

Avenue

Drayton Valley, Alberta

T7A 1A1

ATTENTION: Annette Driessen

1.0 INTRODUCTION

This report presents the results of the geotechnical investigation and analysis made on the

two potential sites of the proposed Drayton Valley Aquatic Centre, to be located near the Omniplex

property in Drayton Valley, Alberta. Environmental issues are beyond the scope of this this report.

The objective of the investigation was to determine the subsoil conditions to aid in

foundation design and construction. Authorization to proceed was received from Annette Driessen

the Town of Drayton Valley. Fieldwork was completed in July and August of 2019.

2.0 SITE AND PROJECT DESCRIPTION

The site of the proposed development is near the Omniplex building on the southwest side

of the Town of Drayton Valley, Alberta. Two areas were identified by the client as potential

locations for the proposed Aquatic Centre. The first location was a grass-surfaced field between the

Omniplex and the adjacent Holy Trinity Academy building. The second location was a grass-

surfaced field north of the Omniplex parking lot. The project is understood to consist of a two-

storey building, roughly 2200 square metres in size. A preliminary drawing showing the

approximate size and shape of the proposed building was forwarded to our firm by the client. The

drawing shows a lane pool, leisure pool and some smaller pools along with associated change

rooms and office spaces.

HOGGAN ENGINEERING & TESTING (1980) LTD. 2

Coal Mine Atlas Review

The Alberta Coal Mine Atlas produced by the Energy Resources Conservation Board was

checked for the subject site and no workings were noted within the project boundaries. Coal mining

related issues should not be a concern for this site and were not investigated further.

Geology

According to the Quaternary Geology of Central Alberta conducted by I. Shetsen, 1990, the

geology of the area predominately consists of glacial deposit of draped moraine till of uneven

thickness, with minor amounts of water-sorted material and local bedrock exposures; up to 10

metres thick. Including local areas of undifferentiated subglacially molded deposit with streamlined

features; flat to undulating surface reflecting topography of underlying bedrock and other deposits.

The bedrock of the area is of the Paskapoo formation of Paleogene age. It consists of

recessively weathering, grey to greenish-grey mudstone and siltstone with subordinate pale grey

sandstone with minor conglomerate, mollusc coquina, and coal.

3.0 FIELD INVESTIGATION

The soils investigation for this project was undertaken on July 26 and August 2, 2019

utilizing a truck mounted drill rig owned and operated by SPT Drilling Ltd. of St. Albert, Alberta.

A total of five testholes were drilled, as shown on the attached site plan. Two testholes were

advanced at proposed building Location A, adjacent to Holy Trinity Academy, and three testholes

were advanced at proposed building Location B, north of the shared parking lot. The testholes were

advanced to a depth of 11.9 meters below ground surface (BGS). The testholes were advanced at

locations chosen by Hoggan based on a preliminary plan provided to our firm by the client. The

testholes were located in the field by Hoggan prior to drilling.

The testholes were advanced with 150-millimeter diameter solid stem augers in 1.5-meter

increments. A continuous visual description was recorded on site which included the soil types,

depths, moisture, transitions, and other pertinent observations. Disturbed samples were removed

from the auger cuttings at 750-millimeter intervals for laboratory testing. Standard Penetration Tests

c/w split spoon sampling was also taken at regular 1.5-meter intervals.

Following the drilling operation, a slotted piezometric standpipe was inserted into each

testhole for watertable level determination. The testholes were backfilled with cuttings, with a


bentonite seal placed at the surface. Watertable readings were obtained 7,18, and 33 days after the

initial drilling. The testholes were surveyed for location and elevation by Hoggan personnel using a

handheld Trimble GPS unit.

4.0 LABORATORY TESTING

All disturbed bag samples returned to the laboratory were tested for moisture content. In

addition, the plastic and liquid Atterberg Limits and soluble soil sulphate concentrations were

determined on selected samples. Lab results are included on the attached testhole logs located in the

Appendix.

5.0 SOIL CONDITIONS

A detailed description of the soils encountered is found on the attached testhole logs in the

Appendix. In general, the soil conditions at this site consisted of topsoil, underlain by clay,

overlaying clay till. A layer of clay fill was also found near the surface of Testhole 2019-1 and

2019-2.

Surficial topsoil was encountered at the surface of all testholes to depths in the range of 100

and 150 millimeters. The topsoil depths are known at individual testhole locations and may vary in

between.

Below the topsoil in Testholes 2019-1 and 2019-2, clay fill material was encountered. The

fill generally consisted of a silty, sandy, moist, brown clay. The clay fill had a medium to high

plasticity and a stiff to very stiff consistency and featured trace organics. The clay fill was

encountered to depths in the range of 0.9 to 1.1 meters BGS.

Below the fill in Testholes 2019-1 and 2019-2, a high plastic, lacustrine clay was

encountered. The high plastic clay was a native deposit with a stiff to very stiff consistency. The

high plastic clay was considered moist and silty and featured traces of coal. Atterberg limit

analysis on these clays indicated liquid limits of 70 to 79 percent and plastic limits of 25 to 26

percent. The lacustrine clay was encountered to depths between 3.7 and 4.0 metres BGS.

Below the high plastic clay in Testholes 2019-1 and 2019-2 and below the topsoil in

Testholes 2019-3, 2019-4, and 2019-5, a till-like clay was encountered. The clay was a native

deposit of medium plasticity and a stiff to very stiff consistency and featured traces of coal,

oxides and gravel. The clay was typically silty and moist with brown and grey coloring. This


material was encountered to depths between 6.1 and 7.0 metres BGS.

Below the till-like clay, in all testholes, a glacial clay till was encountered. The clay till

was a native deposit which was considered silty, sandy and moist with a very stiff consistency.

The clay till was typically medium plastic and featured traces of coal, oxides and gravel. The

clay till was encountered to the termination depth of approximately 11.9 meters BGS in all

testholes.

At the completion of drilling, no significant accumulations of slough or water were

encountered in any of the testholes.

6.0 GROUNDWATER CONDITIONS

The groundwater table within the study area was considered high. Two sets of watertable

readings were taken, as well as one additional reading for Location A, with the results listed in the

table below.

2-Aug 13-Aug 28-Aug Watertable

Testhole Elevation (7/- Days) (18/11 Days) (33/26 Days) Elevation

2019-1 851.06 0.69 0.79 1.15 849.91

2019-2 850.26 0.40 0.45 0.90 849.36

2019-3 854.29 - 1.20 1.45 852.84

2019-4 853.52 - 1.14 1.10 852.42

2019-5 852.80 - 0.99 0.92 851.88

Groundwater Table Readings

Proposed Drayton Valley Aquatic Centre

(meters below ground surface)

It should be noted that water table levels may fluctuate on a seasonal or yearly basis with

the highest readings obtained in the spring or after periods of heavy rainfall. The above readings

would be above average seasonal water table levels.

7.0 RECOMMENDATIONS

7.1 Footings

1. A footing foundation system is considered geotechnically marginally satisfactory for this

project based on the soils encountered in the testholes. The issue with footing foundations at

this site being the high plastic clay soil at Location A, in Testholes 2019-1 and 2019-2. The

footing must be founded on undisturbed, native non-organic soil. The fill material

encountered in Testholes 2019-1 and 2019-2 is not considered suitable for footing support.


The following factored bearing capacities (Ultimate Limit States) may be used for footing

design, and apply to both sites:

Geotechnical Factored Bearing Factored Bearing

Resistance Resistance Resistance

Soil Stratum Factor (Strip Footing) (Spread Footing)

Topsoil/Clay Fill 0.5 0 kPa 0 kPa

Clay 0.5 90 kPa 105 kPa

Clay Till 0.5 175 kPa 210 kPa

These figures include the total of all live and dead loads. All perimeter footings

within a continuously heated structure should have a minimum 1.5 meters frost cover, with a

minimum cover of 2.5 meters for a non-continuously heated structure or exterior isolated

footings.

2. The watertable levels in the standpipes at 33/26 days were between 0.9 and 1.5 meters BGS.

This late summer level likely represents above average levels of the year. The depth of

footing excavation is anticipated to be below the water table and significant dewatering

efforts will likely be required. Dewatering methods are best determined in the field during

construction.

3. The near surface clays encountered at Location A, in Testholes 2019-1 and 2019-2, were

high plastic in nature, meaning that they are highly susceptible to swelling and shrinkage

with changes in moisture content. It should be noted that when footings are constructed on

high plastic soils, there is a risk of foundation movement from shrinkage and swelling of the

clays, especially during extreme dry or wet weather periods. The subgrade soils should not

be allowed to dry excessively. The risk of foundation movement must be accepted by the

owner if footing foundation on high plastic clay is desired. The risk can best be managed by

diligent drainage design and maintenance, preventing moisture changes to the clays below

the foundation. If the moisture content of the clay does not change, then movement does not

occur. Pile foundations or deeper footings are recommended if foundation movement cannot

be tolerated.

4. Our firm did not conduct consolidation testing at this site. However, settlement should not

be an issue at the above noted bearing capacities, given the glacial, over-consolidated nature


of the clays, and assuming that proper construction procedures are adhered to. As such, the

Ultimate Limit States (ULS) values can be considered to also be the Serviceability Limit

States (SLS) values.

5. To ensure adequate performance of the foundation system, continuous footings should be

designed as a beam with adequate reinforcing and should be integrated with the foundation

walls, if applicable. Such design procedures would permit foundation components to

withstand a small amount of differential movement induced by any soil volume changes.

6. Care should be taken during construction and the life of the structure to prevent excessive

changes in moisture content of the material. Footing excavations should be protected from

drying, rain, snow, freezing, and the ingress of groundwater.

7. No loose, disturbed, remoulded or slough material should be allowed to remain in the open

footing excavations. Hand cleaning is advised if an acceptable surface cannot be prepared

by mechanical equipment. Excavations should be dug with equipment operating remote

from the bearing surface.

8. All interior backfill against foundation walls should be inorganic material and should be

compacted to an equivalent of at least 98 percent of the corresponding Standard Proctor

Density at optimum moisture content. The backfill should be placed in lifts not greater than

150 millimeters after compaction.

9. Water dispersed on the property from the roof leaders must not be allowed to accumulate

against the foundation walls. To ensure positive drainage, the soil surface should be made

sloping away from the building. It is recommended that a positive lot grading of at least five

percent away from the foundation walls for soft surfaces and a minimum of two percent for

hard surfaces be provided for a minimum of 5.0 meters from foundation walls. Overall lot

grading must direct all run-off away from the building.

10. During cold weather construction, it is essential that all interior fill and load bearing

materials remain frost free. Recommended cold weather construction practices, with respect

to hoarding and heating of the forms and the fresh concrete, must be strictly followed. If

doubts remain as to the suitability of the foundation soils during construction, our firm

should be consulted.

7.2 Cast-In-Place Piles

1. The soils encountered at this site were considered suitable for a cast-in-place concrete pile


foundation. The design capacity was can be calculated on the basis of factored skin friction

or end bearing values. A combination of the two bearing modes is acceptable for individual

piles, although the skin friction should be neglected in any bell areas to 1.0 metre above the

bell.

2. The following factored skin friction values may be used for pile design, and apply to both

sites:

Geotechnical Factored Skin

Soil Stratum Resistance Factor Friction Resistance (ULS) CLAY (1.5-7.0 metres BGS) 0.4 16 kPa

CLAY TILL 0.4 24 kPa

The above values include the total of all live and dead loads. Considering the effects of

frost and seasonal moisture changes, the friction value for the first 1.5 metres of pile

should not be considered in design. This may be reduced to 0.6 metres for interior piles in

continuously heated buildings.

3. It should be noted that Serviceability Limit States (SLS) addresses the functional

performance of a structure as opposed to Ultimate Limit States (ULS) which addresses

failure. Therefore, the geotechnical issue for SLS loading on piles is settlement rather than

bearing capacity. While the predicted settlement of a pile is not readily calculated, the

typical expectation of a building placed on a pile foundation is essentially no settlement at

all. In this case, the expected settlement for a skin friction pile loaded to the above factored

bearing values would be less than 10 millimetres. Therefore, if settlements of 10 millimetres

or less are acceptable, the design values provided in this section can be considered to be

ULS and SLS values.

4. The recommended minimum pile depths at this site for frost uplift prevention in straight

shaft piles are 4.5 metres in a continuously heated structure and 6.0 metres in a non-

continuously heated structure. The minimum pile diameter for all piles should be 400

millimetres, with a minimum skin friction pile spacing of 2.5 pile diameters on center.

5. The factored end-bearing values that may be used are as follows:

Geotechnical Factored End-

Soil Stratum Resistance Factor Bearing Resistance (ULS)

CLAY TILL 0.4 300 kPa


The above values include the total of all live and dead loads. End bearing piles should

extend to a minimum of three bell diameters below ground surface, and should have a

maximum bell to shaft ratio of 3:1. The bell should be fully formed in the clay till, with the

bottom of the bell penetrating this material by a minimum of 1.0 metre.

6. Bell formation may be difficult due to sand lenses within the till. Although the current

testhole program did not encounter sand or very sandy layers within the clay till, these sand

deposits are random in nature and may be encountered nonetheless. Bells should not be

formed in these sandy layers, but penetrate deeper until more suitable soil is encountered.

This may require lengthening of reinforcement onsite. Design changes may be required in

the field during construction.

7. All pile holes should be carefully inspected to ensure that no water or slough material is

present prior to concrete placement. Although no significant accumulations of slough or

water were noted during testhole drilling, the high water table indicates potential for slough

and water to be produced during pile installation. Casing should be available on-site during

drilling of the pile holes. In addition, whether casing is required or not, the pile concrete

should be placed as soon as possible after the pile has been bored to minimize the volume of

ingressing groundwater.

8. Due to the nature of this project, lateral load information may be required. A coefficient of

horizontal subgrade reaction may be applied to the analysis of soil resistance for laterally

loaded piles according to the following:

Coefficient of Lateral Subgrade Reaction (kN/m3) Soil Stratum

CLAY 5,000/d

CLAY TILL 10,000/d

(where d is the diameter of the pile in metres)

For design purposes, the top 1.5 metres of pile length should be disregarded. Additional

lateral load information can be provided once pile dimensions have been chosen and the pile

stiffness becomes known.

9. Some provision should be made for the possible swelling of the subsoil beneath the pile caps

and the effects of frost action. This can be done by providing a void form or other provision


for a minimum 75 millimetres of potential soil expansion beneath the grade beams and pile

caps.

10. It is recommended that all piles be adequately reinforced. Concrete for all piles should be

adequately vibrated.

11. All structural fill against foundation walls should be an inorganic material compacted in 150

millimetre lifts to at least 98 percent of the corresponding Standard Proctor Density at

optimum moisture content.

12. Surface grading should be made sloping away from the foundation walls.

7.3 Seismic

1. Based on the site soil properties and the Alberta Building code, the Site Classification for

Seismic Site Response is Class C.

7.4 Building Excavation

1. A maximum 4 metre depth was assumed for the temporary excavation. The excavation is

assumed to be open for a maximum of one month.

2. For the temporary excavation slopes to remain stable during the facility construction, a

minimum cutback angle of 2:1 (horizontal:vertical) is recommended. Exact values for

excavation slopes cannot be pinpointed without detailed and extensive analysis. For this

reason, this information should be used as a guideline only and the optimum cutback angles

should be determined in the field during construction. It is not recommended that

excavations be left open for extensive periods of time. The Occupational Health and Safety

Act, Part 32 - Excavations and Tunnelling should be strictly followed except where

superseded by this report. Slickensides were noted in the upper clays at Location A, which

indicate the potential for failure in the excavation sideslopes. Our firm should inspect the

excavation walls during digging to look for slickensides and recommend action accordingly.

All slopes should be monitored regularly for signs of sloughing or movement, especially

after any periods of rainfall, and remediation should be performed immediately wherever

such signs are observed.

3. Exterior walls should have suitable damp proofing where adequate drainage is provided.

Cold joints in the concrete should be sealed with a suitable sealant. Vapour barrier, and other

slab-on-grade recommendations should be followed for the slab.


4. For temporary shoring, the lateral earth pressure values provided below in Point 6 may be

used. The shoring design should be carried out in co-operation with our firm once

construction details have been finalized. The type of shoring will dictate the pressure

distribution that should be utilized and it may not be triangular as per the formula in Item 6

below.

5. Excavation cuts below the watertable may produce a soft slab subgrade over time and with

construction traffic. Placing a 150-millimeter thick mud slab or a 300 to 500-millimeter

thick granular sub-base with a non-woven geotextile separator is an option to provide a

working platform. The granular sub-base should be clean and well graded with a 75

millimeter maximum nominal size. The granular sub-base should be placed in one lift and in

such a manner as to minimize disturbance to the excavation base and static rolled for

compaction. Caution should be used if allowing concrete trucks or heavy equipment to

travel upon the excavation sub-base. Preferably, a concrete pump truck should be utilized,

operating from outside the excavation. The need for the working platform and its

configuration should be decided in the field during excavation.

6. The foundation walls should be designed to resist lateral earth pressures. For walls which

will not rotate, the “at-rest” or Ko coefficients should be utilized. Active earth pressure

coefficients (Ka) should be utilized for walls that are allowed to rotate (unrestrained at the

top). The earth pressure may be calculated using the following equation:

P = K (σ’ + q)

where: P = lateral earth pressure (kPa)

K = coefficient of earth pressure (Ko or Ka)

σ’ = effective stress (γ H - u) (kPa)

γ = bulk unit weight of backfill soil (kN/m3)

H = depth below final grade (m)

u = pore water pressure (kPa)

q = surcharge pressure at ground level (kPa)

Excavations and foundation walls may be designed utilizing the following lateral earth

pressure values that are approximate for this site:


Rankine Coefficients for Lateral Earth Pressure

Soil

Effective

Friction

Angle - ’

Ko Ka Kp

Total Unit

Weight

kN/m3

Native undisturbed Clay 25 0.6 0.4 2.5 19

Native undisturbed Clay Till 30 0.5 0.3 3.0 21

Clay fill and clay backfill, compacted at 95

to 97%

of Standard Proctor Density

25 0.6 0.4 2.5 19

Clean granular backfill, compacted at 95 to

97% of Standard Proctor Density 35 0.4 0.3 3.7 22

7. Backfill should not be over compacted (i.e. to greater than 97 percent of SPD) as this will

induce higher lateral earth pressures on the structure. Only hand operated compaction

equipment should be used within 600 millimeters of the walls. Minimum compaction

should be 95 percent in maximum 300-millimeter lifts. An allowance for surcharge

pressures induced by compaction equipment should be considered. Clay backfill should

be placed slightly above optimum moisture content.

7.5 Slab-on-Grade and Pool Structure

1. All topsoil and deleterious material should be completely removed from below the slab.

The fills encountered near the surface of Testholes 2019-1 and 2019-2 (Location A) are

considered unsuitable for slab-on-grade support. The native subsoils at the anticipated

slab elevation are medium to high plastic and as such have a moderate to high potential

for swelling/shrinkage. If the slab is placed near or upon the high plastic native clays,

there is potential for large slab movement due to shrinkage and swelling. The natural

moisture content near the surface was above optimum thereby reducing the swelling

potential, but increasing the shrinkage potential. When using a slab-on-grade, all interior

walls supported by the slab must have design and finishing details that allow for

movement. In addition, the slab should be structurally separated from other components

of the proposed structure, and allowed to float independently of the exterior foundation


and interior telepost pads. Joints between interior slab-supported walls and exterior

foundation supported walls must be flexible.

2. A minimum 150-millimeter layer of clean granular material with a maximum size of 25

millimeters should be placed immediately below the slab-on-grade. This material should

be compacted to the equivalent of 98 percent of the Standard Proctor Density at optimum

moisture content.

3. Any imported clay fill material used for slab support should be placed in 150 millimetre lifts

and compacted to an equivalent of at least 98 percent of the corresponding Standard Proctor

Density at optimum moisture content. This fill should be low to medium plastic in nature,

and free of organic content, with a liquid limit less than 40%.

4. For slab thickness design considerations, a subgrade modulus (k) of 15 MN/m3 may be

applied for the native undisturbed clay and clay till.

5. In such areas as furnace rooms where there is an intense concentrated heat, adequate

provisions should be made to protect the supporting subsoil from excessive desiccation.

These areas should be well-insulated so that soil volume changes beneath the floor slabs

may be kept to a tolerable amount.

6. A non-deteriorating vapour barrier should be placed beneath the concrete floor to prevent

desiccation of the subgrade material.

7. Drayton Valley is located within an area that has been identified by the national research

council to have high levels of relative Radon hazard. Radon is a tasteless, odourless,

colourless gas potentially emitted by the site subsoil and is a health concern. As per

Section 6.2.1.1 of the Alberta Building Code 2014 Volume 2, Radon prevention system

should be addressed for all new building construction.

One method of addressing the Radon prevention system may include a minimum

100-millimeter thick crushed Radon rock layer below the slab for Radon ventilation

purposes. This crushed Radon rock layer may increase to 150 millimeters thick to substitute

the granular base recommended in Item 2. The crushed Radon rocks should meet the

following ASTM C33/C33M-16 #5 aggregate specifications.


Sieve Size (mm) Minimum Passing Maximum Passing

37.5 100 100

25.0 90 100

19.0 20 55

12.5 0 10

9.5 0 5

Table 8: Radon Rock Gradation

A non-woven geotextile separator (Nilex 4551 or similar) should be placed between

the soil subgrade and the Radon rock layer to prevent infiltration of fines into the Radon

rocks. Radon gas extraction issues from the Radon rock layer are beyond the scope of this

report.

In addition, this Radon prevention system should also include an air tight vapor

seal between the Radon rock and bottom of slab. For Radon mitigation purposes, the

vapor barrier should be a minimum 10 mil in thickness and bonded together with air tight

seal. The air tight vapor barrier can be used as the vapor retarder recommended in Item 6.

8. Radon mitigation products, such as Radon Guard and others are being routinely

introduced to the construction industry. These products generally meet the criteria for air

flow in order to mitigate the radon gas below the slab. Use of such radon mitigation

products may have adverse effects on the slab-on-grade in certain applications. It is

recommended that that radon mitigation system be reviewed by a qualified geotechnical

engineer.

9. The slabs should contain sufficient reinforcing to control cracking due to vertical

movement caused by shrinkage and swelling of the underlying material. Adequate crack

control joints should be provided.

10. It is important that surface grading around the proposed building should be made sloping

away from the foundation walls. Roof drainage must not collect adjacent to the building.


7.6 Surface Utilities

1. The subsurface soil conditions encountered at this site are generally considered fair for the

construction of surface facilities. The fill encountered in the testholes contained variable

amounts of organic material, and may not be suitable for surface utility support. Any topsoil

and other deleterious or organic material, including fill with significant organic content, is

considered unsuitable for pavement support and should be removed from the area prior to

construction. For budgetary purposes, it is recommended that all existing fill onsite be

classified as unsuitable. Ultimately, the suitability of the existing fill would be best

determined by a proofroll and visual inspection after the site is free of snow and frost. The

near surface clays encountered in the testholes were medium to high plastic in nature, and

are considered moderately to highly susceptible to swelling and shrinkage with changes in

moisture content.

2. Cement stabilization is the recommended subgrade preparation method at this site. Past

experience has shown that cement stabilization is effective in reducing the swelling potential

of clays and in maintaining the subgrade strength during the design life.

Application rates would best be determined in the field during construction. Based

on the logs, a budget of 20kg/m2 of cement mixed to a depth of 300 millimetres is

recommended by JRP for this project. As a minimum, the addition of 10 kilograms of

cement per square meter of subgrade mixed to a depth of 150 millimetres and compacted

to 100 percent of SPD is recommended. Moister areas will require more cement mixed to

greater depths, typically up to 30 kilograms of cement per square meter mixed to a depth

of 300 millimetres. All subgrade should be proof rolled after final compaction and any

areas showing visible deflections should be inspected and repaired as required. Increased

cement stabilization rates and mixing depths will likely be required for areas near catch

basins/manholes, failure areas and intersections as these areas often have increased

moisture and softer soil conditions. Rates of 20-30 kg/m2 mixed to a depth of 300

millimetres should be expected where these conditions are encountered. Deeper cement

stabilization may also be required where repetitive construction traffic operates upon the

subgrade surface or weather conditions soften the bearing surface during removals and

reconstruction.

3. If fill is required to bring the subgrade up to design elevation, it is recommended that


medium plastic clay be used. All fill should be placed in lifts not greater than 150

millimetres in thickness, and should be compacted to a minimum of 98 percent of

Standard Proctor Density, near optimum moisture content.

4. It is imperative that positive surface drainage of the pavement be established to prevent

ponding of surface water. All subgrade and surfaces should be sloped to provide adequate

drainage, as this is critical for good long-term structure performance.

5. The moisture content of the near-surface soils was increasing with depth. Due to the high

water table, cuts are not recommended in the pavement areas. The structures provided below

are grade dependant; where cuts are planned, increased pavement structures will be

required.

6. The following 20 year pavement designs may be applied to the proposed site. An estimated

Subgrade Resilient Modulus (Mr) of 30 MPa is used in the design as well as a design life of

20 years. The pavement designs presented below are typical of parking lot loads. It is critical

when structures of varying depths are utilized that adequate drainage is provided at the base

of the deeper gravel structure such that ponding of water is not allowed. These structures

may be modified if a more accurate traffic loading estimate is forwarded. It is recommended

that structures be individually designed for special loading circumstances.

Car and Light Truck Areas Medium Duty Pavement Areas

(3 x 104 ESALs) (3 x 10

5 ESALs)

Asphaltic Concrete 100 mm (12.5-LD) 100 (12.5-HD)

Crushed Gravel (20 mm) 200 mm 350 mm

Notes: 12.5-HD = Town of Drayton Valley - Heavy Duty Asphaltic Concrete

12.5-LD = Town of Drayton Valley - Light Duty Asphaltic Concrete

All gravel should be compacted to 100 percent of SPD in maximum 200 mm lifts.

Recommended Pavement Structures

Proposed Drayton Valley Aquatic Centre

7. Areas that experience channeled truck traffic or point loads, such as in front of garbage

bins or truck loading bays should feature reinforced concrete pads. These pads should be

individually designed for specific loading and usage. The recommended concrete

pavement specifications are a minimum 28 day compressive strength of 30 MPa, non-

reinforced, an air content of 5 to 7 percent, CSA Type GU normal hydraulic cement, and


adequate saw-cuts should be installed.

8. It is imperative that any underground utility trenches be properly backfilled and

compacted. Failure to do so may result in a soft subgrade and therefore increased

subgrade measures and pavement structures.

7.7 Cement

The following alternatives are advised:

1. Underground Concrete Pipe

Concrete used for all underground pipes must be constructed of C.S.A. Type HS (high

sulphate resistant hydraulic cement).

2. Above Ground/Sidewalks

All concrete for surface improvements such as sidewalks and curbs may be constructed

using C.S.A. Type GU (general use hydraulic cement).

3. Foundation Construction

Tests on selected soil samples indicated negligible or low concentrations of water-soluble

soil sulphates in the near surface clay deposits. Based on C.S.A. Standards A23.1-14, Type

GU (general use hydraulic cement) can be used for all concrete coming into contact with the

soil. All concrete exposed to freezing conditions should be air entrained to between 5 and 7

percent. Other exposure factors should be considered when choosing a minimum strength

for the concrete. Concrete should conform to CSA Standards A23.1-14.


A P P E N D I X

TH 2019-1N: 5909779.9mE: 334285.5mA: 851.06mWT: 849.91m

Holy Trinity Academy

49 Avenue

45 Avenue

LOCATION "A"

LOCATION "B"

TH 2019-2N: 5909774.5mE: 334304.6mA: 850.26mWT: 849.36m

Omniplex

TH 2019-3N: 5909963.0mE: 334146.3mA: 854.29mWT: 852.84m

TH 2019-4N: 5909948.3mE: 334189.4mA: 853.52mWT: 852.42m

TH 2019-5N: 5909983.0mE: 334224.9mA: 852.80mWT: 851.88m

45 Avenue

Drayton Valley RV Park

TH IDN: NorthingE: EastingA: Altitude (MSL)WT: Watertable Altitude

LEGEND

3TM Coordinates Zone CM120W

SCALE: 1:1500

Figure 1FILE #: 6604-4

DATE: September 2019

Approximate Testhole LocationsProposed Drayton Valley Aquatic Centre

Near 5749 - 45 AvenueDrayton Valley, Alberta

(Base Image Courtesy of Google Earth)

.

OR

FILL

CH

CI

CI

TOPSOIL

CLAY FILL : silty, moist, trace sand, stiff to verystiff, medium to high plastic, brown and dark brown,trace organics

CLAY : native, some silt, moist, stiff to very stiff,high plastic, brown and grey, some slickensides,trace rootlets, trace coal-below 1.8m: no rootlets

-below 2.4m: moist to very moist, occassional verymoist sand laminations, trace pebbles

-below 4.0m: till-like features, medium plastic,uniform olive grey/brown colour

-at 5.3m: trace free water noted on SPT

CLAY TILL : silty, sandy, moist, very stiff, mediumplastic, uniform grey colour, trace coal, tracepebbles

END OF TESTHOLE @ 11.9 m. No water and noslough on completion of testhole.

7 day waterlevel reading: 0.69 m bgs.18 day waterlevel reading: 0.79 m bgs.33 day waterlevel reading: 1.15 m bgs.

7

7

7

6

10

13

13

14

150 mm

1.1 m

6.1 m

P.L. = 26.0 L.L. = 70.5 M.C. = 32.2Soluble Sulphates: Negligible


17505 - 106 AvenueEdmonton, AB T5S 1E7Phone: (780) 489-0700Fax: (780) 489-0800

COMPLETION DEPTH: 11.89 m

COMPLETION DATE: 07/26/19

1

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Dep

th (

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Ele

vatio

n (m

)

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15

850

849

848

847

846

845

844

843

842

841

840

839

838

837

SO

IL S

YM

BO

L

SOILDESCRIPTION

LOGGED BY: B Burke

REVIEWED BY: A Rahime

0

MO

DIF

IED

US

CS

JRP

6

60

4-4

.GP

J JR

PV

2_

6.G

DT

10

/15

/19

CORE SAMPLE NO RECOVERYSAMPLE TYPE

PROJECT NO: 6604-4

DRILL METHOD: Solid Stem Auger

BOREHOLE NO: 2019-1

ELEVATION: 851.06 m

SHELBY TUBE



OWNER: Town of Drayton Valley

GRAB SAMPLESPT SAMPLE

LOCATION: N 5909779.9, E 334285.49

DRILL CUTTINGSBENTONITE GROUTBACKFILL TYPE PEA GRAVEL SANDSLOUGH

SP

T (N

)

OTHERDATA

M.C.

SA

MP

LE T

YP

E

LIQUID

20 40 60 80

PLASTIC

POCKETPEN. (kPa) 100 200 300 400

SLO

TTE

DP

IEZO

ME

TER

1.15

849.

91

30.4

20.7

24.9

32.2

35.2

35.2

23.6

22.9

18.4

18.4

17.9

18.5

17.8

18.7

18.3

16.9

17.3

18.3

17.2

18.4

16.8

16.1

17.7

26 70.5

13.3 35.4

.

OR

FILL

CH

CI

CI

TOPSOIL

CLAY FILL : silty, moist, trace sand, stiff to verystiff, medium to high plastic, brown and dark brown,trace organicsCLAY : native, some silt, moist, stiff to very stiff,high plastic, brown and grey, some slickensides,trace rootlets, trace coal-below 1.5m: no rootlets

-below 3.7m: till-like features, medium plastic,uniform olive grey/brown colour


-below 7.0m: very stiff

CLAY TILL : silty, sandy, moist, very stiff, mediumplastic, uniform grey colour, trace coal, tracepebbles


7 day waterlevel reading: 0.4 m bgs.18 day waterlevel reading: 0.45 m bgs.33 day waterlevel reading: 0.9 m bgs.

9

7

9

11

13

21

17

100 mm

900 mm

7.6 m

P.L. = 19.9 L.L. = 53.8 M.C. = 26.2


Shelby Tube: QU: 167.88 kPa DD: 1848 Kg/m3

MC: 17.4 %




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850

849

848

847

846

845

844

843

842

841

840

839

838

837

836

SO

IL S

YM

BO

L

SOILDESCRIPTION

LOGGED BY: B Burke


0

MO

DIF

IED

US

CS

JRP

6

60

4-4

.GP

J JR

PV

2_

6.G

DT

10

/15

/19


PROJECT NO: 6604-4


BOREHOLE NO: 2019-2

ELEVATION: 850.26 m

SHELBY TUBE





LOCATION: N 5909774.46, E 334304.55


SP

T (N

)

OTHERDATA

M.C.

SA

MP

LE T

YP

E

LIQUID

20 40 60 80

PLASTIC

POCKETPEN. (kPa) 100 200 300 400

SLO

TTE

DP

IEZO

ME

TER

0.9

849.

3631.5

26.2

28.6

34.6

34.7

40.4

36.3

35.2

17.4

19.5

17.9

19.5

21.1

22

21

18.7

19.3

18.4

17.5

16.9

16.9

19.1

17.1

16.5

19.9 53.8

25.3 79.6

.

OR

CI

CI

TOPSOIL

CLAY : native, some silt, moist, stiff, mediumplastic, brown and grey, some slickensides, tracerootlets, trace coal

-below 1.5m: no rootlets

CLAY TILL : silty, sandy, moist, very stiff, mediumplastic, uniform dark brown/grey colour, trace coal,trace pebbles


-below 6.1m: grey


11 day waterlevel reading: 1.2 m bgs.26 day waterlevel reading: 1.45 m bgs.

9

11

13

15

15

13

19

22

100 mm

2.4 m






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854

853

852

851

850

849

848

847

846

845

844

843

842

841

840

SO

IL S

YM

BO

L

SOILDESCRIPTION

LOGGED BY: B Burke


0

MO

DIF

IED

US

CS

JRP

6

60

4-4

.GP

J JR

PV

2_

6.G

DT

10

/15

/19


PROJECT NO: 6604-4


BOREHOLE NO: 2019-3

ELEVATION: 854.29 m

SHELBY TUBE





LOCATION: N 5909962.99, E 334146.26


SP

T (N

)

OTHERDATA

M.C.

SA

MP

LE T

YP

E

LIQUID

20 40 60 80

PLASTIC

POCKETPEN. (kPa) 100 200 300 400

SLO

TTE

DP

IEZO

ME

TER

1.45

852.

84

32.5

35.4

33.3

21.8

32.1

24.2

19.7

19.2

21.4

19.5

18.9

19.4

18.4

17.3

18.1

17.8

18.2

18.5

17.1

14.9

16.4

16.4

13.3

15.6

14.9 42.1

14 39.1

.

OR

CI

CI

TOPSOIL

CLAY : native, some silt, moist, stiff, mediumplastic, brown and grey, some slickensides, tracerootlets, trace coal-below 0.6m: very stiff, trace oxides and gravel


-at 2.3m: trace free water noted on SPTCLAY TILL : silty, sandy, moist, very stiff, mediumplastic, uniform dark brown/grey colour, trace coal,trace pebbles

-below 4.6m: gradual transition to grey

-at 7.6m: wet sand laminations



10

9

14

15

13

11

14

20

100 mm

2.4 m

P.L. = 15.5 L.L. = 40.8 M.C. = 24.0





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849

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843

842

841

840

839

SO

IL S

YM

BO

L

SOILDESCRIPTION

LOGGED BY: B Burke


0

MO

DIF

IED

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CS

JRP

6

60

4-4

.GP

J JR

PV

2_

6.G

DT

10

/15

/19


PROJECT NO: 6604-4


BOREHOLE NO: 2019-4

ELEVATION: 853.52 m

SHELBY TUBE





LOCATION: N 5909948.33, E 334189.39


SP

T (N

)

OTHERDATA

M.C.

SA

MP

LE T

YP

E

LIQUID

20 40 60 80

PLASTIC

POCKETPEN. (kPa) 100 200 300 400

SLO

TTE

DP

IEZO

ME

TER

1.1

852.

42

36.2

25.9

21.9

24

18.4

18.4

18.8

18.4

18.6

18.3

18.9

18.2

17.9

18.5

17.8

18.4

19.3

18.8

19.6

18.6

16.9

15.8

17

15.6

15.5 40.8

13.1 40.9

.

OR

CI

CI

TOPSOIL

CLAY : native, some silt, moist, stiff, mediumplastic, brown and grey, some slickensides, tracerootlets, trace coal


CLAY TILL : silty, sandy, moist, very stiff, mediumplastic, uniform dark brown/grey colour, trace coal,trace pebbles




7

13

13

9

10

12

18

100 mm

2.1 mP.L. = 14.7 L.L. = 37.6 M.C. = 18.7Shelby Tube: QU: 164.49 kPa DD: 1757 Kg/m3

MC: 19.0 %

P.L. = 13.3 L.L. = 38.4 M.C. = 17.2




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849

848

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846

845

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843

842

841

840

839

838

SO

IL S

YM

BO

L

SOILDESCRIPTION

LOGGED BY: B Burke


0

MO

DIF

IED

US

CS

JRP

6

60

4-4

.GP

J JR

PV

2_

6.G

DT

10

/15

/19


PROJECT NO: 6604-4


BOREHOLE NO: 2019-5

ELEVATION: 852.8 m

SHELBY TUBE





LOCATION: N 5909983.02, E 334224.85


SP

T (N

)

OTHERDATA

M.C.

SA

MP

LE T

YP

E

LIQUID

20 40 60 80

PLASTIC

POCKETPEN. (kPa) 100 200 300 400

SLO

TTE

DP

IEZO

ME

TER

0.92

851.

8835.4

31.3

24.7

20.8

18.7

19

19

18.6

18.5

17.7

17.4

17.1

17.2

19.1

19.7

18.5

17.8

19.5

18.2

17.5

16.5

18.3

16.3

15.9

14.7 37.6

13.3 38.4

Date post:	20-Oct-2021
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REPORT NO: 6604-4 GEOTECHNICAL INVESTIGATION …

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