GEOTECHNICAL ASSESSMENT AND DESIGN · segment design work, Wood carried out an assessment of the...

Prepared for:

R.F. Binnie & Associates Ltd.

#300 – 4940 Canada Way, Burnaby BC V5G 4M5

12 June 2020

GEOTECHNICAL ASSESSMENT

AND DESIGN

Lynx Creek East Segment

Highway 29, British Columbia

Project # KX052807.11

‘Wood’ is a trading name for John Wood Group PLC and its subsidiaries

GEOTECHNICAL ASSESSMENT

AND DESIGN


Highway 29, British Columbia

Project # KX052807.11

Prepared for:

R.F. Binnie & Associates Ltd.

300 - 4940 Canada Way Burnaby BC, V5G 4M5

Prepared by:

Wood Environment & Infrastructure Solutions,

a Division of Wood Canada Limited

3456 Opie Crescent Prince George, BC V2N 2P9

12 June 2020

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Geotechnical Assessment and Design

Lynx Creek East

Project # KX052807.11 | 12 June 2020 Table of Contents

Table of Contents

Introduction ........................................................................................................................................................................... 1

General Project Description ............................................................................................................................................. 1

Background Information ................................................................................................................................................... 2

Geology ................................................................................................................................................................... 2

Quaternary Geology ........................................................................................................................................... 2

Geotechnical Site Investigations by Wood ............................................................................................... 3

Description of Highway Alignment and Site Conditions by Station ............................................................... 3

Acid Rock Drainage and Metal Leaching Potential ................................................................................................ 7

Existing Highway 29 Asphalt Thicknesses .................................................................................................................. 7

Slope Stability........................................................................................................................................................................ 8

Design Criteria ...................................................................................................................................................... 8

Slope Stability Models....................................................................................................................................... 8

7.2.1 Material Parameters .......................................................................................................................... 9

7.2.3 Groundwater Conditions ...............................................................................................................12

7.2.4 Geometry .............................................................................................................................................12

Slope Stability Assessment ............................................................................................................................12

7.3.1 Sta. 1004+300 to Sta. 1004+660 ................................................................................................12

7.3.2 Sta. 1004+900 to Sta. 1005+460 ................................................................................................13

7.3.3 Sta. 1005+500 to Sta. 1005+690 ................................................................................................14

7.3.4 Sta. 1005+690 to Sta. 1005+910 ................................................................................................14

7.3.5 Sta. 1005+910 to Sta. 1005+970 ................................................................................................15

7.3.6 Sta. 1006+120 to Sta. 1006+200 ................................................................................................16

7.3.7 Sta. 1006+200 to Sta. 1006+780 ................................................................................................16

7.3.8 Sta. 1006+860 to Sta. 1007+030 ................................................................................................17

7.3.9 Sta. 1007+030 to Sta. 1007+070 ................................................................................................17

Impact of Long-Term Reservoir Erosion ...................................................................................................................18

West of Sta. 1005+100 ....................................................................................................................................18

Between Sta. 1005+400 and 1005+800 ...................................................................................................18

Between Sta. 1005+860 and 1006+000 ...................................................................................................19

Settlement Analyses .........................................................................................................................................................19

Soil Stress History .............................................................................................................................................19

Soil Compressibility Parameters ..................................................................................................................20

Granular Soil .......................................................................................................................................20

Cohesive Soil ......................................................................................................................................20

Embankment Stress Distribution ................................................................................................................21

Settlement Estimates .......................................................................................................................................21

Time Rate of Consolidation ...........................................................................................................................24

Secondary Compression Settlements .......................................................................................................24

Settlement of Existing Fill...............................................................................................................................24

Settlement Mitigation ......................................................................................................................................................25

Instrumentation ..................................................................................................................................................................26

Slope Inclinometer Casing ............................................................................................................26

Settlement Plates ..............................................................................................................................................27

Vibrating Wire Piezometers ..........................................................................................................................27

Large Diameter Culvert Headwalls ..............................................................................................................................28

Subgrade Conditions .......................................................................................................................................28

Soil Bearing Capacity .......................................................................................................................................29


Lynx Creek East


Frost Design Considerations .........................................................................................................................29

Lateral Earth Pressures ....................................................................................................................................30

Sliding Friction Coefficient ............................................................................................................................30

General Recommendations ...........................................................................................................................................30

Stripping ...............................................................................................................................................................30

Subgrade Preparation .....................................................................................................................................33

Embankment Fill Construction .....................................................................................................................33

Cut Slope Construction ...................................................................................................................................34

Temporary Excavations ...................................................................................................................................34

Culverts and Headwalls...................................................................................................................................35

Geotextile and Biaxial Geogrid Specifications .......................................................................................35

Pavement Structure ..........................................................................................................................................36

Soil Waste Disposal ..........................................................................................................................................37

Designated Soil Waste Disposal Sites........................................................................................................................37

Site B8 ....................................................................................................................................................................38

Site B9 ....................................................................................................................................................................38

Geotechnical Recommendations by Station ...........................................................................................................38

Closure ...................................................................................................................................................................................47

References ............................................................................................................................................................................48

List of Appendices

APPENDIX A FIGURES 1 TO 4, GEOTECHNICAL INVESTIGATION

FIGURE 5, SHEAR KEY STA. 1005+940

APPENDIX B FIGURES 6 TO 26, SLOPE STABILITY ANALYSES


Lynx Creek East


List of Tables

Table 6-1: Encountered Asphalt Thickness................................................................................................................................. 7

Table 7-1: Target Factors of Safety for Slope Stability Assessment ................................................................................. 8

Table 7-2: Location of Slope Stability Models .......................................................................................................................... 9

Table 7-3: Parameters used to Estimate Effective Stress Residual Friction Angle for Cohesive Soils .............. 10

Table 7-4: Total Stress Strength Parameters for Cohesive Soils ..................................................................................... 11

Table 7-5: Summary of Material Properties used in the Slope Stability Models ...................................................... 11

Table 7-6: Sta. 1004+440, Results of Slope Optimization (Optimized Slopes Shown in Figure 6) ................... 12

Table 7-7: Sta. 1004+440, Results of Slope Stability Assessment (Figure 7) ............................................................. 13

Table 7-8: Sta. 1005+260, Results of Slope Optimization (Optimized Slopes Shown in Figure 8) ................... 13

Table 7-9: Sta. 1005+260, Results of Slope Stability Assessment (Figures 9 and 10) ............................................ 13

Table 7-10: Sta. 1005+600, Results of Slope Optimization (Optimized Slope Shown in Figure 11) ................ 14

Table 7-11: Sta. 1005+600, Results of Slope Stability Assessment (Figure 11) ........................................................ 14

Table 7-12: Sta. 1005+820, Results of Slope Optimization (Optimized Slopes Shown in Figure 12) .............. 14

Table 7-13: Sta. 1005+820, Results of Slope Stability Assessment (Figures 13 and 14) ....................................... 15

Table 7-14: Sta. 1005+940, Results of Slope Stability Assessment (Figure 15 and 16) ......................................... 15

Table 7-15: Sta. 1006+200, Results of Slope Optimization (Optimized Slopes Shown in Figure 17) .............. 16


Table 7-17: Sta. 1006+520, Results of Slope Optimization LHS (Optimized Slope Shown in Figure 20) ....... 16

Table 7-18: Sta. 1006+520, Results of Slope Stability Assessment (Figures 20 through 22) .............................. 17



Table 9-1: Culvert Locations and Descriptions ...................................................................................................................... 19

Table 9-2: Results of Incremental Load Consolidation Test ............................................................................................. 20

Table 9-3: Estimated Compression and Recompression Indices .................................................................................... 21

Table 9-4: Estimated Settlement at Culvert Location, below Road Centerline ......................................................... 22

Table 9-5: Estimated Differential Settlement along Culverts ........................................................................................... 23

Table 9-6: Time Rate of 95% Consolidation Considering Two-Way Drainage ......................................................... 24

Table 10-1: Estimated Differential Settlement and Settlement Criterion .................................................................... 25

Table 10-2: Settlement Mitigation .............................................................................................................................................. 26

Table 11-1: Slope Inclinometer Casings ................................................................................................................................... 27

Table 11-2: Settlement Plates ....................................................................................................................................................... 27

Table 11-3: Vibrating Wire Piezometers ................................................................................................................................... 28

Table 12-1: Headwall and Collar Locations, and Pipe Diameter ..................................................................................... 28

Table 12-2: Summary of Subsurface Conditions at Headwall and Collar Locations ............................................... 28

Table 12-3: Factored Ultimate Bearing Capacities ............................................................................................................... 29

Table 12-4: Earth Pressure Coefficients under Static Condition for Various Sloping Conditions ..................... 30

Table 13-1: Stripping Depths by Station .................................................................................................................................. 31

Table 13-2: Non-Woven Geotextile Specifications .............................................................................................................. 35

Table 13-3: Biaxial Polypropylene Geogrid Specifications ................................................................................................ 36

Table 13-4: Recommended Minimum Pavement Structure Thickness ........................................................................ 36

Table 13-5: Likely Locations for Non-Woven Geotextile Separator below SGSB .................................................... 36



Project # KX052807.11 | 12 June 2020 Page 1

Introduction

As part of BC Hydro’s proposed Site C Clean Energy Project, portions of the existing Highway 29

alignment between Hudson’s Hope and Charlie Lake, BC, will be flooded during normal reservoir

operation. Before filling of the reservoir, the affected portions of the highway will be relocated away from

the reservoir area. In support of the project, Wood Environment & Infrastructure Solutions a Division of

Wood Canada Limited (Wood), formerly Amec Foster Wheeler, was retained by R.F. Binnie & Associates

Ltd. (Binnie) to provide geotechnical engineering services in support of proposed realignment for an

approximately 2.95 km long segment (Sta. 1004+330 to Sta. 1007+280) of Highway 29, referred to herein

as Lynx Creek East. The general location of the Lynx Creek East segment is shown in Figure 1 and a plan of

the proposed realignment is provided on two plan sheets in Figure 2, both in Appendix A.

General Project Description

The proposed 2.95 km long Lynx Creek East realignment segment is referenced as the L1000-Line (Binnie

Plan dated 17 April 2020) which comprises a 2-lane paved highway. The west end of the Lynx Creek

realignment starts at Sta. 1004+330 and extends in a northeasterly direction generally north (left) of and

parallel to the existing Highway 29 to approximately Sta. 1006+350, where it will cross Highway 29. East of

approximately Sta. 1006+350, the new alignment follows the left bank of the Peace River until it merges

back into Highway 29 at approximately Sta. 1007+280. A plan of the proposed L1000-Line is provided on

two map sheets in Figure 2. Figure 3 (Sheets 1 to 5) depicts a profile view along the new highway

alignment centreline. Figure 4 (Sheets 1 to 6) depicts cross-sections at various points along the alignment.

Figures 1 through 4 are in Appendix A. The terms left hand side (LHS) and right hand side (RHS) are used

to refer to the north and south sides of the alignment, respectively.

For detailed descriptions of the background topographic, geology and terrain conditions along the

project segment, the reader is referred to definition design phase reporting (AMEC, 2012).

East of approximately Sta. 1004+800 to approximately Sta. 1007+080 the L1000-Line traverses several

alluvial fan terrain features. Wood carried out an assessment of the debris flow risk associated with the

alluvial fan features and presented the results in a memo dated 04 November 2019 (Wood, 2019a).

Between approximately Sta. 1006+260 and the eastern limit of the Lynx Creek East segment, the highway

is located on an approximately 25 m high embankment that will be partially founded in the current Peace

River. An in-river Early Works platform nominally higher than the water level in the Peace River is to be

constructed in this area prior to construction of the alignment. Design RHS embankment fill slopes in this

area will be confirmed after geotechnical drilling is carried out from the surface of the in-river platform.

Beyond the eastern limit of the Lynx Creek East segment, the existing highway is tightly constrained

between a large landslide feature known as the Farrell Creek Road Slide, which is located above and to the

left of the highway, and a steep erosional slope down into the Peace River on the right. An in-stream

reservoir shoreline stability berm is proposed along the steep erosion slope. As part of the Lynx Creek East

segment design work, Wood carried out an assessment of the Farrell Creek Road Slide and the proposed

in-stream reservoir shoreline stability berm and presented the results in a memo dated 17 December 2019

(Wood, 2019b).




Background Information

Geology

The Peace region of British Columbia is part of the Peace River Lowland, of the Alberta Plateau sub-

province of the Northern Interior Plains (Bidwell, 1999, Hartman and Clague, 2008). It has plateaus and

gently rolling upland areas that have been deeply incised into the underlying soil and bedrock by the

Peace River and its tributaries. Within this region are found uplands, river valleys, and raised terraces. The

uplands can be characterized as steep to gently rolling ridges with bedrock typically near ground surface.

The top of the terrace features have little relief, although scarps are located between the terrace levels.

The terraces are located within and adjacent to river valleys. The area has undergone many stages of

glacial advance and retreat. Since the last glaciation, the Peace River rapidly eroded the current valley

(Hartman and Clague, 2008).

Bedrock geology is summarized from Geological Survey of Canada Bulletin 328 (Stott, 1982), the Lynx

Creek East segment is underlain by gently northeast-dipping sedimentary beds of the Lower Cretaceous

age. Mapping identifies the site as near the contact between the overlying Shaftesbury Formation and the

underlying Boulder Creek, Hulcross and Gates Formations.

The Boulder Creek Formation is described as consisting of fine-grained, laminated sandstone with

interbedded mudstone, and the formation is described as laying gradationally on the underlying marine

shales and siltstones of the Hulcross Formation.

The Hulcross Formation is described as consisting of rubbly, silty dark grey to black shale or mudstones.

The silt content is noted to increase upward through the member with thin beds of argillaceous siltstone

and sandstone occurring in the uppermost part of the member.

In the vicinity of Gates Island, the Gates Formation is described as consisting of massive, thick-bedded,

fine-grained, well-sorted sandstone that often forms overhanging cliffs.

Bedrock exposed in a gully (colloquially known as the amphitheater) on the left bank of the river across

from Gates Island is identified as the Hulcross Formation overlying the Gates Formation, and the Boulder

Creek Formation is noted to be possibly exposed near the top of the gully.

Quaternary Geology

The quaternary geology upstream of Halfway River, as described by BGC (2012), suggests that the

overburden soils comprising the valley wall of the Peace River likely consist of the following units:

1. Glacial Lake Peace (Interbedded Sand, Silt and Clay), over

2. Laurentide Till, over

3. Interbedded layers of valley infill sediments including glaciolacustrine deposits (e.g. Glacial Lake

Mathews) and granular fluvial deposits.

Glacial Lake Peace and Laurentide Till are located on the plain above the Peace River Valley, and valley

infill sediments are located within the Peace River Valley. Due to down cutting of the modern Peace River,

there may only be remnants of the older valley infill sediments within the Peace River Valley. The valley

bottom sediments in the vicinity of Lynx Creek are more likely to consist of younger, post-glacial, granular

fluvial channel, terrace deposits, fine-grained (silt/clay) over-bank flood plain deposits, and colluvial

sediments derived from adjacent valley slopes.




Geotechnical Site Investigations by Wood

To support design for the Lynx Creek East segment, Wood carried out geotechnical site investigations in

2018 and 2019. The bulk of the geotechnical investigation work was carried out in 2018 for the original

definition design alignment; however, in January 2019, a significant northerly alignment shift away from

the definition design was proposed and subsequently a supplemental geotechnical investigation specific

to the new alignment was carried out in 2019. Information from the investigations is presented in a

geotechnical data report (Wood, 2019c). The boundary of the west end of the Lynx Creek East segment

was subsequently shifted 370 m west, information from the Lynx Creek West geotechnical data report

(Wood, 2020) was used for analyses in that area.

Description of Highway Alignment and Site Conditions by

Station

For the purposes of geotechnical assessment and design, the L1000-Line was divided into sections having

similar topographic, geological and geometric design geometries. These sections are described below.

Subsurface conditions along the alignment centerline are summarized in Figure 3 (Sheets 1 to 5) and in

cross sections at various points along the alignment, shown in Figure 4 (Sheets 1 to 6), all in Appendix A.

Sta. 1004+330 to Sta. 1004+660: The alignment transitions from an upper to a lower terrace largely on

an embankment. The section includes cuts approximately 5 m deep and an embankment up to 5 m high.

A culvert goes through the embankment at Sta. 1004+430. The culvert is corrugated steel pipe, with a

diameter of 0.9 m, a length of 61.5 m, a gradient of 1.4% and a skew of 135°.

Subsurface conditions below the upper terrace (area of cut) generally consisted of gravel with variable

amounts of sand and silt, over bedrock. The bedrock surface elevation is variable and was encountered at

470.1 and 473.1 m elevations. The cut slope may encounter bedrock. Subsurface conditions below the

lower terrace (area of fill) generally consisted of clay between 3.6 m depth to greater than 5 m depth. In

two test holes sand was located below the clay. Groundwater was inferred at 6.2 m depth at

CPT18-LX-008.

Sta. 1004+660 to Sta. 1004+780: The alignment is scratch grade. The section includes shallow fills of

less than 2 m and ditch cuts of up to 1 m. TP18-LX-039 encountered clayey sand to 2.4 m depth, over

gravel to 2.7 m depth, over silt and clay. Bedrock and groundwater were not encountered within the

depth of the investigation.

Sta. 1004+780 to Sta. 1004+840: The alignment crosses an entrenched drainage channel and is located

near the distal edge of an alluvial fan. The entrenched drainage channel is crossed by a culvert at Sta.

1004+812. The culvert is corrugated steel pipe, has a diameter of 2.4 m, a length of 27.5 m, a gradient of

4%, a skew of 105° and headwalls at the inlet and outlet. Riprap check dams are proposed upstream of

the inlet and a riprap basin is proposed downstream of the inlet. Subsurface conditions below the culvert

generally consisted of silt and sand.

Subsurface conditions along the highway section generally consisted of sand and gravel, interbedded with

silt and clay, over shale bedrock. Bedrock was encountered at approximate 460 m elevation

(approximately 10 m below the proposed alignment grade). Groundwater was not encountered at the

investigation locations in this section.

Sta. 1004+840 to Sta. 1004+900: The alignment is scratch grade. The section includes shallow fills of

less than 2 m and ditch cuts of up to 1 m. TP18-LX-041 encountered sand and gravel to 1.4 m depth, over

silt to the bottom of the test pit at 4.9 m depth. Groundwater was not encountered.




Sta. 1004+900 to Sta. 1005+460: The alignment is on an embankment up to 9 m high. Subsurface

conditions generally consisted of a mixture of silt and clay, interbedded with sand and gravel, over shale

bedrock. Bedrock was encountered between 3.1 and 7.6 m below ground surface. Groundwater was

inferred in CPT19-LX-202 and 204 at 2.4 and 2.7 m depths, respectively.

Culverts are located and Sta. 1005+075 and 1005+285. The culvert at Sta. 1005+075 is corrugated steel

pipe, has a diameter of 1.2 m, a length of 42.5 m, a gradient of 2.7% and a skew of 90°. The culvert at

Station 1005+285 is corrugated steel pipe, has a diameter of 1.2 m, a length of 57.0 m, a gradient of 0.8%

and a skew of 90°.

Sta. 1005+460 to Sta. 1005+500: The alignment crosses a drainage channel and is located near the

distal edge of an alluvial fan. The drainage channel is crossed by a culvert at Sta. 1005+487. The culvert is

corrugated steel pipe, has a diameter of 2.0 m, a length of 54.5 m, a gradient of 5.9%, a skew of 122° and

headwalls at the inlet and outlet. Riprap check dams are proposed upstream of the inlet and a riprap

armored drainage channel is proposed downstream of the outlet. Ground conditions below the culvert

generally consisted of interbedded layers of silt and sand, and clay and silt.

General subsurface conditions along the highway section consisted of a mixture of silt and clay over shale

bedrock. Based on CPTu data, bedrock is inferred at approximately 12 m below ground surface.

Groundwater was encountered at 9.4 m depth in TH19-LX-207 and inferred at 6.1 m depth in

CPT19-LX-206.

Sta. 1005+500 to Sta. 1005+690: The alignment has a cut up to 10 m deep into the edge of an alluvial

fan. Subsurface conditions consisted of a mixture of silt and clay interbedded with sand and gravel, over

shale bedrock. Bedrock was encountered between 12.3 and 18.7 m below ground surface but is not

anticipated in the cut slope. Groundwater was encountered at 9.1 m depth in TH19-LX-210 and inferred at

6.1 m depth in CPT19-LX-211.

Sta. 1005+690 to Sta. 1005+910: The alignment is on an embankment up to 13 m high. Subsurface

conditions generally consisted of clay up to 13.7 m depth, over shale bedrock. Bedrock was encountered

between 7.8 and 14.6 m below ground surface. Groundwater was encountered at 3.7 m depth in

TP18-LX-044 and inferred at 8.5 m depth in CPT19-LX-215.

A culvert is located at Sta. 1005+820. The culvert is corrugated steel pipe, has a diameter of 1.6 m, a

length of 37.5 m, a gradient of 2.1%, a skew of 90° and a headwall at the inlet. Ground conditions below

the headwall generally consisted of clay and silt, ground conditions below the culvert will transition to

embankment fill that becomes increasing thicker (up to 3 m) towards the outlet.

Sta. 1005+910 to Sta. 1005+970: The alignment has a cut up to 7 m deep into the edge of an alluvial

fan. Subsurface conditions consisted of a mixture of silt and clay, over sand, over bedrock. Bedrock was

encountered between 12.8 and 23.3 m below ground surface and is not anticipated in the cut slope.

Groundwater was not encountered at the investigation locations in this section.

Sta. 1005+970 to Sta. 1006+200: The alignment is on an embankment up to 15 m high. Waste soil is

proposed to be placed adjacent to the LHS embankment slope up to elevation 465 m. Subsurface

conditions generally consisted of clay or gravel over shale bedrock. Bedrock was encountered between 2.4

and 3.8 m below ground surface. Groundwater was encountered at 1.5 m depth in TH18-LX-029 and

inferred at 5.6 m depth in CPT19-LX-219.


length of 41.0 m, a gradient of 1.5% and a skew of 90°. The culvert invert will be located approximately

5 m below highway surface (465 m elevation), and between 4 and 5 m above current ground surface.




Sta. 1006+200 to Sta. 1006+400: The alignment is on an embankment up to 15 m high and crosses over

the existing highway. Subsurface conditions generally consisted of clay, over sand and gravel, over

bedrock. Clay was up to 8.5 m thick and bedrock was encountered at 9.5 m depth. Groundwater was not

encountered at the investigation locations in this section.

Sta. 1006+400 to Sta. 1006+780: The alignment is on an embankment 15 m high on the left side of

highway and 25 m high on the right side of the highway. Waste soil is proposed to be placed up to

approximately 465 m elevation. The toe of RHS embankment slope is on the in-river Early Works platform

which is the granular fill placed in the Peace River prior to construction of the balance of the Lynx Creek

East highway segment. Subsurface conditions left of and below the existing highway generally consisted

of silt and clay over shale bedrock, in some areas layers of gravel and silt were encountered. Subsurface

conditions right of the highway generally consisted of sand and gravel with varying silt content, over shale

bedrock. It is anticipated that the existing highway and RHS slope beside the existing highway may be

underlain by fill of variable composition and density. An existing slide is located on the RHS slope below

the highway between Sta. 1006+380 to Sta. 1006+460. Groundwater was inferred at 10.5 m depth in

CPT19-LX-222, and 4.1 m depth in CPT19-LX-227.

Between approximately Sta. 1006+200 and Sta. 1006+670 the LHS of the embankment is located on the

distal edge of three separate but coalesced/overlapping alluvial fans. Culverts are located at Sta.

1006+450, 1006+500 and 1006+658.

The culvert at Sta. 1006+450 is corrugated steel pipe, has a diameter of 1.2 m, a length of 43.0 m, a

gradient of 2.5% and a skew of 90°. The culvert invert will be located approximately 5 m below highway

surface (at 465 m elevation) and between 7 and 15 m above current ground surface.


gradient of 2.0%, a skew of 90° and headwalls at the inlet and outlet. The culvert invert will be located

approximately 7 m below highway surface (at 465 m elevation) and between 8 and 20 m above current

ground surface. Riprap check dams are proposed upstream of the inlet.


gradient of 2.4% and a skew of 90°. The culvert invert will be located approximately 4 m below highway

surface (at 465 m elevation) and between 10 and 20 m above current ground surface.

Sta. 1006+780 to Sta. 1006+860: The alignment is on an embankment 8 m high on the left side of

highway and 25 m high on the right side of highway. Waste soil is proposed to be placed up to

approximately 465 m elevation between the LHS embankment slope and the natural ground surface to

the north. The toe of the RHS embankment slope is on the in-river platform. Subsurface conditions below

the existing highway generally consisted of highway fill, over clay and silt, over gravel, over shale bedrock.

Highway fill is likely variable in composition and density, with zones of potentially loose fill. Subsurface

conditions right of the highway generally consisted of sand and gravel interbedded with silt and clay, over

bedrock. Fill may have been side cast over the RHS of the highway. A historic highway fill slope failure (i.e.

slide) is located between 1006+780 and 1006+930. The slide was remediated, likely in 1979-1980;

however the current condition of the remediation works and the current stability of the slide is unknown.

Groundwater was not encountered at the investigation locations in this section, but groundwater is likely

at a depth comparable to the elevation of the Peace River.

Sta. 1006+860 to Sta. 1007+030: The alignment begins to merge back into the existing highway. The

left side embankment slope becomes progressively shorter. Between Sta. 1006+860 and 1006+900 waste

soil is proposed to be placed up to approximately 465 m elevation between the LHS embankment slope

and the natural ground surface to the north. The right side embankment slope is 25 m high with the toe

of the slope on the in-river platform. Subsurface conditions generally consisted of highway fill, over silt




and clay interbedded with sand and gravel, over shale bedrock. The highway fill is likely variable in

composition and density, with zones of potentially loose fill. A relatively recent existing slide is located on

the RHS between approximately Sta. 1006+900 and Sta. 1007+030. The slide could not be accessed

during the site investigation, it is anticipated that the slide is in colluvium and/or side cast fill or waste soil.

Groundwater was not encountered at the investigation locations in this section, but groundwater is likely

at a depth comparable to the elevation of the Peace River.


length of 31.5 m, a gradient of 1.8% and a skew of 90°. The culvert invert will be located approximately

3 m below the highway surface (at 465 m elevation) and between 1 and 13 m above current ground

surface.

Sta. 1007+030 to Sta. 1007+070: The alignment crosses a relatively well known debris flow and flood

site. The alignment is on an embankment 2 m high on the left side of highway and 28 m high on the right

side of highway. The toe of the RHS embankment slope is on the in-river platform. Subsurface conditions

generally consisted of layers of silty sand, sand, sand and gravel, over shale bedrock. A test pit located in

the debris flow deposit at the toe of the slope encountered sand and gravel; however, it is anticipated that

the deposit will be variable. The existing RHS slope below the highway is likely covered by poorly

compacted end-dumped fill, over colluvium. Groundwater was not encountered at the investigation

locations in this section, but groundwater is likely at a depth comparable to the elevation of the Peace

River.

Left and upslope of the alignment is a large erosional basin, colloquially referred to by various BCMoTI

geotechnical practitioners as the ‘amphitheater’. Periodic precipitation events and diverted road drainage

from Farrell Creek Road (located above the amphitheater) can result in debris flow and flood events that

reach and cross the existing highway at the current culvert location. The new culvert, located at Sta.

1007+055 is corrugated steel pipe, has a diameter of 2.4 m, a length of 33.5 m, a gradient of 9.5% and a

skew of 98°. Head walls are located at the culvert inlet and outlet. The culvert invert will be located

approximately 3 m below highway surface. The inlet headwall and upper 2/3 of the culvert will likely be

founded on granular colluvium and the lower 1/3 and outlet headwall will be founded on embankment fill

up to 3 m thick. Riprap check dams are proposed upstream of the inlet.

Sta. 1007+070 to Sta. 1007+280: The alignment merges back into the existing highway. The left side

embankment slope is a nominal height and the right side embankment slope is 28 m high with the toe of

the slope on the in-river platform. Subsurface conditions generally consisted of silty sand interbedded

with clay, over shale bedrock. The existing RHS slope below the highway is likely covered by poorly

compacted end-dumped fill or waste soil, over colluvium. Groundwater was not encountered at the

investigation locations in this section, but groundwater is likely at a depth comparable to the elevation of

the Peace River. A relatively recent existing slide is located on the RHS between approximately Sta.

1007+140 and 1007+230.

Beyond the eastern limit of the Lynx Creek East segment (Sta. 1007+280) an in-stream reservoir shoreline

stability berm is located along the toe of a steep erosional slope which forms the north bank of the Peace

River. The in-stream reservoir shoreline stability berm is designated the L2 alignment. The western limit of

the L2 alignment (Sta. 2+380) coincides approximately with Sta. 1007+130 of the L1000 alignment. The in-

stream stability berm is located below a relatively recent existing slide located between approximately Sta.

2+390 and 2+490 (Sta. 1007+140 and 1007+230, noted above). The instream stability berm is also located

below existing slope instability features between approximately Sta. 2+610 and 2+800. East of Sta. 2+800

the in-stream stability berm is located below a steep gradient and eroded slope.




Acid Rock Drainage and Metal Leaching Potential

Planned earthworks for the highway alignment may encounter shale bedrock in a cut slope between Sta.

1004+300 and 1004+380, elsewhere bedrock is not anticipated to be encountered.

Acid Rock Drainage (ARD) and Metal Leaching (ML) testing has not been carried out on bedrock samples

collected within the Lynx Creek East project area. ARD and ML testing on primarily sandstone bedrock

samples collected west of the project area were classified according to BCMoTI Technical Circular T-04/13

as non-acid generating with low potential to produce ARD; however, testing on shale samples east of the

project area were classified as potentially acid generating (PAG). The boundary between the PAG bedrock

to the east and the non-acid generating bedrock to the west is unknown. It is therefore recommended

that, unless proven otherwise, all bedrock encountered during construction be considered PAG. Excavated

bedrock should be disposed of in an environmentally appropriate manner and should any surface

exposures of bedrock remain after excavation, the exposures should be appropriately treated with a cover

(e.g. backfill) as needed.

Existing Highway 29 Asphalt Thicknesses

An asphalt drilling program was carried out along the existing pavement surface of Highway 29. The

program consisted of 12 boreholes spaced at approximately 180 m. The boreholes are designated with

the prefix PV. Near the east end of the project, asphalt thickness was determined as part of deeper site

investigation boreholes that are designated with the prefix TH. The locations of the holes are shown on

Figure 2. The encountered thickness of asphalt is provided in Table 6-1.

Table 6-1: Encountered Asphalt Thickness

Hole Identification Asphalt Thickness (m)

PV18-LX-025 0.15

PV18-LX-026 0.17

PV18-LX-027 0.12

PV18-LX-028 0.11

PV18-LX-029 0.17

PV18-LX-030 0.18

PV18-LX-031 0.12

PV18-LX-032 0.26

PV18-LX-033 0.081

PV18-LX-034 0.231

PV18-LX-035 0.101

PV18-LX-036 0.141

PV18-LX-037 0.141

TH18-LX-037 0.101

TH18-LX-039 0.101

TH18-LX-041 0.101

TH18-LX-044 0.101 Note: 1 Asphalt layer would be covered by the new highway embankment.

New highway embankments are located above the existing highway pavement surface between

approximately Sta. 1006+040 and the east end of the segment (Sta. 1007+280). If the new embankment is

constructed over the asphalt surface, the relatively smooth asphalt surface can become a potentially weak

layer and reduce the stability of the embankment. Where the relatively impermeable asphalt layer is




located below the MNRL, the layer can also disrupt internal drainage of the embankment during a

reservoir rapid drawdown event. For those reasons, it is recommended that the asphalt surface be

removed below the footprint of new embankments and that the underlying gravel surface be scarified

prior to construction of the new embankment. Note that the slope stability assessments described in

Section 7.3 assume the asphalt layer is removed and the underlying gravel surface scarified and, therefore,

the corresponding recommended fill slope angles also assume the asphalt layer is removed and underling

gravel surface scarified.

At the tie-in between the new alignment and existing highway at the east end of the project (Sta.

1007+280) the existing asphalt thickness is unknown. For design purposes it is recommended to assume

an existing asphalt thickness of 0.10 m.

Slope Stability

To assess the stability of the proposed cut and fill slopes, slope stability analyses were carried out using

the Slope/W computer program included in the GeoStudio 2016 package by GEO-SLOPE International

Ltd. (GEO-SLOPE, 2016). The analyses were carried out using limit equilibrium methods.

Design Criteria

The design criteria used for the slope stability assessment is described in the document ‘BC Hydro Site C –

Highway 29 Relocation, Geotechnical Design Criteria (Version 2.8)’, dated 20 February 2020. Based on that

document, the slope stability assessment used the target factors of safety noted Table 7-1, which consider

a typical understanding and typical consequence of failure.

Table 7-1: Target Factors of Safety for Slope Stability Assessment

Scenario Limit State Target Factor of

Safety

Maximum Normal Reservoir Level (elev. 461.8 m) Global Stability – Permanent 1.54

Emergency Reservoir Drawdown Event Global Stability - Temporary 1.24

The maximum normal reservoir level and emergency reservoir drawdown event scenarios were analyzed

using effective stress conditions, and as described in the design criteria document.

Temporary stability during construction of cut and fill slopes was analyzed using total stress strength

parameters (i.e. undrained shear strength) for cohesive soils For cases where the total stress analyses

resulted in a factor of safety less than 1.24, instrumented staged construction can be implemented to

monitor and control groundwater pressure generation during construction in order to maintain required

stability.

Slope Stability Models

Slope stability models were developed based on the subsurface information noted in the geotechnical

data reports (Wood, 2019c and Wood, 2020) and the proposed geometry for the L1000-Line. Note that

slope stability models are a simplification of actual ground conditions. Slope stability models were

developed at the locations noted in Table 7-2.




Table 7-2: Location of Slope Stability Models

Location Description

Sta. 1004+440 Embankment Fill, 5 m high LHS & RHS

Sta. 1005+260 Embankment Fill, 5 m high LHS, 9 m high RHS

Sta. 1005+600 Cut Slope, 8 m deep LHS


Sta. 1005+940 Cut Slope, 5 m deep LHS





Slope stability models relating to the in-stream stability berm, located beyond the eastern limit of the

Lynx Creek East segment, can be found in the Farrell Creek Road Slide and In-Stream Reservoir Shoreline

Stability Berm memo, dated 17 December 2019 (Wood, 2019b). The in-stream stability berm is proposed

along a steep erosion slope along the Peace River below a section of the existing Highway 29 alignment

which is to remain in place upon reservoir filling. The memo describes slope stability analyses carried out

at Sta. 1007+316 and 1007+490.

7.2.1 Material Parameters

Material parameters were determined based on several sources of information including observations

made during drilling, CPTu data, laboratory testing, and correlations between soil index properties and

soil strengths presented in published literature. It is anticipated that stability of the cut and fill slopes will

be largely dependent on the relatively low shear strength of underlying cohesive soil layers (e.g. clay and

silt).

Effective Stress Strength Parameters for Cohesive Soil

Based on Wood’s experience in the Peace Region, fissures can be present within cohesive soil indicating

that regions within the soil mass could be at a state of residual effective strength. For the purpose of the

effective stress stability analyses cohesive soil is assumed to be at a residual strength with no cohesion.

The residual effective strength of the cohesive soil was estimated using an empirical correlation relating

the Atterberg liquid limit, clay size fraction (particles smaller than 0.002 mm) and effective normal stress to

the residual friction angle (Stark and Eid, 1994). The residual shear strength values obtained from the

correlation are for an assumed effective normal stress of 100 kPa.

The Atterberg liquid limit and clay size fractions were obtained from the geotechnical data report (Wood,

2019c and Wood, 2020) and grouped by station segment, as noted in Section 4.0. A summary of the

parameters input into the Stark and Eid correlation and the corresponding residual friction angle for the

model locations noted in Table 7-2 is included in Table 7-3, below.




Table 7-3: Parameters used to Estimate Effective Stress Residual Friction Angle for Cohesive Soils

Location Unit Name

Liquid

Limit

(%)

Clay

Fraction

(%)

Effective

Normal

Stress

(kPa)

Residual

Effective

Friction

Angle

(Degrees)

Sta. 1004+440 Clay (CL) 47 53 100 18

Sta. 1005+260 Clay (CL) 50 50 100 18

Sta. 1005+600 Clay (CL) 41 24 100 23

Sta. 1005+820 Clay (CL) 44 41 100 22

Sta. 1005+940 Clay (CL) 43 40 100 22

Sta. 1006+200 Clay (CL) 44 39 100 22

Sta. 1006+520 Clay (CL) 55 57 100 17

Sta. 1007+000 Clay/Colluvium (CL) 38 19 100 28

Sta. 1007+060 Clay/Colluvium (CL) 38 10 100 28

Total Stress Strength Parameters for Cohesive Soil

During construction of the embankments the underlying cohesive soils will develop positive pore

pressures during consolidation, reducing the effective stress within the soil (Φ’ = 0), and stability becomes

a function of the immediate strength (undrained shear strength) of the cohesive soil. To gauge the

stability of an embankment during construction a total stress analysis was carried out at the locations

noted in Table 7-2.

The undrained shear strength of cohesive soils was estimated based on the CPT tip resistance using the

following equation (Lunne, et. al., 1997).

𝑆𝑢𝐶𝑃𝑇=

𝑞𝑡 − 𝜎𝑣𝑜

𝑁𝑘𝑡

Where:

𝑆𝑢𝐶𝑃𝑇 = undrained shear strength estimated from CPTu

𝑞𝑡 = cone tip resistance

𝜎𝑣𝑜 = total vertical stress of the corresponding depth of measurement of the 𝑞𝑡 value

𝑁𝑘𝑡 = an empirical factor typically between 10 and 20, an assumed 𝑁𝑘𝑡 of 15 was used for the analyses

Cohesive soil layers along the alignment were likely formed as over-bank flood plain deposits or colluvial

sediments derived from adjacent valley slopes. The deposits do not appear to have large-scale, spatially

continuous structure. To characterize the undrained shear strength of these deposits, representative CPT

profiles were reviewed and the undrained shear strength corresponding to the lowest quartile was used in

the analyses. The undrained shear strengths used in the stability analyses are summarized in Table 7-4.




Table 7-4: Total Stress Strength Parameters for Cohesive Soils

Location Unit Name Representative CPT

Undrained Shear

Strength

25th Percentile

(kPa)

Sta. 1004+440 Clay (CL) CPT18-LX-007

CPT18-LX-008 77

Sta. 1005+260 Clay (CL)

(Upper and Lower)

CPT19-LX-202

CPT19-LX-204

CPT18-LX-011

77

Sta. 1005+600 Clay (CL) CPT19-LX-206

CPT19-LX-211 61

Sta. 1005+820 Clay (CL) CPT19-LX-214

CPT19-LX-215 72

Sta. 1005+940 Clay (CL) CPT19-LX-219 144

Sta. 1006+200 Clay (CL)

CPT19-LX-221

CPT19-LX-222

CPT19-LX-223

92

Sta. 1006+520 Clay (CL) CPT19-LX-227 58

Sta. 1007+000 Clay/Colluvium (CL) - 1001

Sta. 1007+060 Clay/Colluvium (CL) - 1001 Note: 1 Due to limited CPT data, an undrained shear strength of 100 kPa was assumed for the Clay/Colluvium.

Material Properties for Granular Soils and Bedrock

The material properties used for granular soil and bedrock are summarized in Table 7-5, below.

Table 7-5: Summary of Material Properties used in the Slope Stability Models

Unit Name Unit Weight

(kN/m3) Cohesion (kPa)

Effective Friction

Angle (Degrees)

Fill (Granular) 21 0 36

Road Fill (Granular) 21 0 28 – 36

Angular Rock Fill 24 0 40

Silty Sand (Loose to Compact) 20 0 29

Sand and Gravel (Loose to Compact) 20 0 31

Gravelly, Silty Sand (Compact) 20 0 30

Sand and Gravel (Dense) 21 0 35

Clay (CL) 19 See

Table 7-4

See

Table 7-3

Shale Bedrock 25 5901 44 1

Shale/Sandstone Bedrock 25 5601 49 1

Sandstone Bedrock 25 15301 60 1 Note: 1 Bedrock strength was estimated using a Mohr-Coulomb failure envelope that is equivalent to a Hoek-Brown failure

criterion using the Roclab computer program developed by Rocscience Inc. (Rocscience, 2007). Zero cohesion was used

+/- 10˚ from horizontal and +/- 20˚ from vertical.




7.2.3 Groundwater Conditions

Groundwater conditions are based on drilling observations and CPTu data collected during the 2018 and

2019 investigations. The analyses were carried out using a Mean Normal Reservoir Level (MNRL) of

461.8 m elevation. During an emergency reservoir drawdown event the water level was assumed to be the

current normal water level of the Peace River or elevation 444 m, whichever is higher.

7.2.4 Geometry

The slope stability models were generated using a simplified geometry based on Binnie’s geometric

design. Areas of fill generally consisted of a 11 m wide embankment top with uniform fill slopes on either

side. Areas of cut generally consisted of a uniform cut slope extending up from a ditch invert located

300 mm below the underside of SGSB.

To achieve the target factors of safety noted in Table 7-1, cut and fill slopes were either steepened or

flattened during the stability analyses. Cut slopes were changed from the ditch invert, and fill slopes were

changed from the top edge of the embankment.

Optimization of cut and fill slopes was carried out by incrementally changing the cut and fill slopes until

the calculated factor of safety was at or slightly above the target factors of safety. Slope optimization was

carried out for the MNRL scenario.

Slope Stability Assessment

The results of the slope stability assessment are summarized in Table 7-6 to Table 7-20, below. Each

section contains a recommendation for maximum fill (or cut) slope angle for design purposes.

Slope stability models that include the in-stream Early Works platform (models at Sta. 1006+520,

1007+000 and 1007+060), are based on the assumption that the in-stream platform is constructed on

high shear strength material (e.g. bedrock or gravel and sand) and the platform itself has a relatively high

shear strength (effective friction angles of 36° and 38° were assumed in the analyses). The in-stream areas

below the platform have yet to be investigated. The in-stream areas and the condition of the platform will

be investigated after construction of the platform. The results from the above noted stability models,

specifically the RHS fill slope, are subject to confirmation following this investigation.

7.3.1 Sta. 1004+300 to Sta. 1004+660

Embankment Fill, 5 m high, left hand side (LHS) and right hand side (RHS).

Table 7-6: Sta. 1004+440, Results of Slope Optimization (Optimized Slopes Shown in Figure 6)

Location Scenario Target Factor of

Safety Fill Slope

Calculated Factor

of Safety

Sta. 1004+440 MNRL, LHS 1.54 3.25H:1.0V 1.63

Sta. 1004+440 MNRL, LHS 1.54 3.20H:1.0V 1.61

Sta. 1004+440 MNRL, LHS 1.54 3.10H:1.0V 1.58

Sta. 1004+440 MNRL, LHS 1.54 3.00H:1.0V 1.55

Sta. 1004+440 MNRL, LHS 1.54 2.95H:1.0V 1.53

Sta. 1004+440 MNRL, RHS 1.54 3.25H:1.0V 1.59

Sta. 1004+440 MNRL, RHS 1.54 3.20H:1.0V 1.58

Sta. 1004+440 MNRL, RHS 1.54 3.10H:1.0V 1.54

Sta. 1004+440 MNRL, RHS 1.54 3.05H:1.0V 1.53




Table 7-7: Sta. 1004+440, Results of Slope Stability Assessment (Figure 7)

Location Scenario

Target

Factor of

Safety

Fill Slope

Calculated

Factor of

Safety

Sta. 1004+440 Emergency Drawdown, LHS1 1.24 3.00H:1.0V 1.55

Sta. 1004+440 Emergency Drawdown, RHS1 1.24 3.10H:1.0V 1.54

Sta. 1004+440 Temporary Construction, LHS2 1.24 3.00H:1.0V 2.24

Sta. 1004+440 Temporary Construction, RHS2 1.24 3.10H:1.0V 2.34 Note: 1 Assumed piezometric surface above MNRL

2 Total stress analysis

Recommendation: LHS maximum fill slope 3.0H:1.0V, RHS maximum fill slope 3.1H:1.0V.

7.3.2 Sta. 1004+900 to Sta. 1005+460

Embankment Fill, 5 m high LHS, 9 m high RHS.



Safety Fills Slope

Calculated Factor

of Safety

Sta. 1005+260 MNRL, LHS 1.54 4.25H:1.0V 1.61

Sta. 1005+260 MNRL, LHS 1.54 4.00H:1.0V 1.55

Sta. 1005+260 MNRL, LHS 1.54 3.95H:1.0V 1.54

Sta. 1005+260 MNRL, LHS 1.54 3.90H:1.0V 1.53

Sta. 1005+260 MNRL, RHS 1.54 4.25H:1.0V 1.55

Sta. 1005+260 MNRL, RHS 1.54 4.20H:1.0V 1.54

Sta. 1005+260 MNRL, RHS 1.54 4.15H:1.0V 1.53

Table 7-9: Sta. 1005+260, Results of Slope Stability Assessment (Figures 9 and 10)

Location Scenario

Target

Factor of

Safety

Fill Slope

Calculated

Factor of

Safety

Sta. 1005+260 Emergency Drawdown, LHS 1.24 3.95H:1.0V 1.54

Sta. 1005+260 Emergency Drawdown, RHS 1.24 4.20H:1.0V 1.62


Sta. 1005+260 Temporary Construction, RHS1 1.24 4.20H:1.0V 3.26 Note: 1 Total Stress Analysis





7.3.3 Sta. 1005+500 to Sta. 1005+690

Cut Slope, 8 m deep LHS.

Table 7-10: Sta. 1005+600, Results of Slope Optimization (Optimized Slope Shown in Figure 11)

Table 7-11: Sta. 1005+600, Results of Slope Stability Assessment (Figure 11)


Safety Cut Slope

Calculated

Factor of Safety

Sta. 1005+600 Emergency

Drawdown, LHS1 1.24 3.10H:1.0V 1.54

Sta. 1005+600

Temporary

Construction,

LHS2

1.24 3.10H:1.0V 2.38

Note: 1 Assumed piezometric surface above MNRL 2 Total stress analysis

Recommendation: LHS maximum cut slope 3.10H:1.0V.

7.3.4 Sta. 1005+690 to Sta. 1005+910




Safety Fill Slope

Calculated Factor

of Safety

Sta. 1005+820 MNRL, LHS 1.54 2.00H:1.0V1 1.83

Sta. 1005+820 MNRL, LHS 1.54 1.90H:1.0V 1.80

Sta. 1005+820 MNRL, LHS 1.54 1.80H:1.0V 1.75

Sta. 1005+820 MNRL, LHS 1.54 1.70H:1.0V 1.71

Sta. 1005+820 MNRL, LHS 1.54 1.50H:1.0V 1.61

Sta. 1005+820 MNRL, LHS 1.54 1.40H:1.0V 1.56

Sta. 1005+820 MNRL, LHS 1.54 1.35H:1.0V1 1.54

Sta. 1005+820 MNRL, LHS 1.54 1.30H:1.0V 1.51

Sta. 1005+820 MNRL, RHS 1.54 4.25H:1.0V 1.62

Sta. 1005+820 MNRL, RHS 1.54 4.15H:1.0V 1.59

Sta. 1005+820 MNRL, RHS 1.54 4.05H:1.0V 1.56

Sta. 1005+820 MNRL, RHS 1.54 4.00H:1.0V 1.54

Sta. 1005+820 MNRL, RHS 1.54 3.95H:1.0V 1.53 Note: 1 To maintain a FoS of 1.54 against shallow instability recommend using a maximum 2.00H:1.0V slope


Safety Cut Slope

Calculated Factor

of Safety

Sta. 1005+600 MNRL, LHS 1.54 3.25H:1.0V 1.57

Sta. 1005+600 MNRL, LHS 1.54 3.20H:1.0V 1.56

Sta. 1005+600 MNRL, LHS 1.54 3.10H:1.0V 1.54

Sta. 1005+600 MNRL, LHS 1.54 3.00H:1.0V 1.50





Location Scenario

Target

Factor of

Safety

Fill Slope

Calculated

Factor of

Safety




Sta. 1005+820 Temporary Construction, RHS1 1.24 4.00H:1.0V 2.46 Note: 1 Total stress analysis


7.3.5 Sta. 1005+910 to Sta. 1005+970

Cut Slope, 5 m deep LHS.

Table 7-14: Sta. 1005+940, Results of Slope Stability Assessment (Figure 15 and 16)

Location Scenario

Target

Factor of

Safety

Cut Slope

Calculated

Factor of

Safety

Sta. 1005+940 Existing Conditions - Natural Slope 1.173

Sta. 1005+940 MNRL, LHS 1.54 2.0H:1.0V 0.943

Sta. 1005+940 MNRL, LHS 1.54 3.0H:1.0V 1.243

Sta. 1005+940 MNRL with Shear Key, LHS 1.54 2.5H:1.0V with Shear

Key

1.55 (below shear key)

1.54 (through shear key)

Sta. 1005+940 Emergency Drawdown with

Shear key, LHS1 1.24

2.5H:1.0V with Shear

Key

1.55 (below shear key)

1.54 (through shear key)

Sta. 1005+820 Temporary Construction,

LHS2 1.24

1.0H:1.0V temporary

cut slope 2.12

Note: 1 Assumed piezometric surface above MNRL


3 Model not shown on figures

Cut slopes flatter than 3.0H:1.0V unlikely feasible due to upslope ground geometry, replacement of toe of

excavation slope with stronger granular or rock shear key material is more effective.

Recommendation: 2.5H:1.0V slope with shear key as shown in Figure 5.




7.3.6 Sta. 1006+120 to Sta. 1006+200




Safety Fill Slope

Calculated Factor

of Safety

Sta. 1006+200 MNRL, LHS 1.54 2.75H:1.0V 1.55

Sta. 1006+200 MNRL, LHS 1.54 2.70H:1.0V 1.53

Sta. 1006+200 MNRL, RHS 1.54 3.25H:1.0V 1.54

Sta. 1006+200 MNRL, RHS 1.54 3.20H:1.0V 1.52



Safety Fill Slope

Calculated

Factor of

Safety




Sta. 1006+200 Temporary Construction, RHS2 1.24 3.25H:1.0V 2.51

Recommendation: maximum fill slope LHS 2.75H:1.0V, maximum fill slope RHS 3.25H:1.0V. LHS fill slope

can be steeper if waste soil is placed at toe of slope.

7.3.7 Sta. 1006+200 to Sta. 1006+780

Embankment Fill, 13 m high LHS, 26 m high RHS on in-river platform. Waste soil placed along LHS slope

up to elevation 465 m.

Table 7-17: Sta. 1006+520, Results of Slope Optimization LHS (Optimized Slope Shown in Figure 20)


Safety Fill Slope

Calculated Factor

of Safety

Sta. 1006+520 MNRL, LHS 1.54 2.00H:1.0V 2.631,2

Sta. 1006+520 MNRL, LHS 1.54 1.50H:1.0V 2.241

Sta. 1006+520 MNRL, LHS 1.54 1.00H:1.0V 1.831 Notes: 1 Assumes fill (waste) placed against toe of LHS slope up to 465 m elevation

2 To maintain a FoS of 1.54 against shallow instability recommend using a maximum 2.00H:1.0V slope




Table 7-18: Sta. 1006+520, Results of Slope Stability Assessment (Figures 20 through 22)

Location Scenario

Target

Factor of

Safety

Fill Slope

Calculated

Factor of

Safety

Sta. 1006+520 MNRL, RHS 1.54 2.5H:1.0V 1.691




Sta. 1006+520 Temporary Construction, RHS3 1.24 3.25H:1.0V 1.60 Notes: 1 RHS fill slope and factor of safety to be confirmed after in-river platform built and additional investigation carried out

2 Assumes fill (waste) placed against toe of LHS slope up to 465 m elevation 3 Total stress analysis

Recommendation: maximum fill slope LHS 2.0H:1.0V, RHS fill slope to be confirmed after additional

investigation carried out.

7.3.8 Sta. 1006+860 to Sta. 1007+030



Location Scenario Target Factor

of Safety Fill Slope

Calculated

Factor of

Safety

Sta. 1007+000 MNRL, RHS 1.54 2.5H:1.0V1 1.561

Sta. 1007+000 Emergency Drawdown, RHS 1.24 2.5H:1.0V1 1.711

Sta. 1007+000 Temporary Construction, RHS2 1.24 2.5H:1.0V1 1.872 Note: 1 RHS fill slope and factor of safety to be confirmed after in-river platform built and additional investigation carried out


Recommendation: RHS fill slope to be confirmed after additional investigation carried out.

7.3.9 Sta. 1007+030 to Sta. 1007+070

Embankment Fill, 2 m high LHS, 28 m high RHS



Safety Fill Slope

Calculated

Factor of

Safety

Sta. 1007+060 MNRL, RHS 1.54 2.5H:1.0V1 1.591

Sta. 1007+060 Emergency Drawdown, RHS 1.24 2.5H:1.0V1 1.581

Sta. 1007+060 Temporary Construction, RHS2 1.24 2.5H:1.0V1 1.562 Note: 1 RHS fill slope and factor of safety to be confirmed after in-river platform built and additional investigation carried out


Recommendation: RHS fill slope to be confirmed after additional investigation carried out.




Impact of Long-Term Reservoir Erosion

In general, the Lynx Creek East segment is constructed on new embankment fill that will be protected

from long-term reservoir erosion through the use of riprap placed at or near the fill toe on the reservoir

side of the embankment. However, based on Binnie’s geometric plans there are three areas were reservoir

erosion was unmitigated and long-term reservoir erosion, as illustrated by BGC’s 2012 Erosion Impact

Lines (EIL), is anticipated to directly or indirectly threaten the global stability of the new highway

alignment.

The current geotechnical design criteria requires slope stability analyses to consider the effects of long-

term reservoir erosion (i.e. the new highway grade is shown to remain stable after 100 years of reservoir

erosion has occurred). For the purpose of the stability assessment it was assumed that from the reservoir

shoreline to the EIL the ground surface will be eroded down to approximately MNRL (481.6 m elevation).

In some locations, even if the long-term erosion (represented by the EIL) does not directly intercept the

new road grade, the erosion if unmitigated would result in loss of the existing ground adjacent to the new

highway alignment such that the global stability criteria is not maintained. The areas where long-term

reservoir erosion is anticipated to compromise stability of the highway alignment are described below.

West of Sta. 1005+100

The unmitigated EIL intersects the new highway alignment at a skew near Sta. 1005+100. The road grade

in this area is at about 471 m elevation and is in small cuts and fills. At the EIL an erosional slope

approximately 9 m high could develop which would compromise the stability of the roadway prism.

Nearby boreholes indicate the area is predominantly underlain by silt and clay; however, layers of sand

and gravel are also present. Slope stability analyses indicate that erosion up to the EIL is unlikely to impact

the new highway alignment west of approximately Sta. 1004+580; however, east of Sta. 1004+580 erosion

protection will be required to prevent the loss of ground that would compromise stability.

Recommendations for erosion mitigation include two options:

1) Excavate riprap into the ground along the reservoir side of road grade between approximately

Sta. 1004+580 and 1005+100. Note that the required excavation could be between 4 and 9 m

deep and the riprap would need to protect a 5H:1V slope geometry to maintain stability of the

road. Excavation and riprap placement would likely need to be carried out prior to construction of

the roadway prism, and the riprap may need to be buried depending on future land use. It is

considered that the volume of excavation for this option would be onerous.

2) Place riprap on the current ground surface close to the reservoir shoreline. To provide adequate

protection east of Sta. 1004+580 the riprap should protect the shoreline of the fan shaped

landform projecting out into the reservoir between Sta. 1004+580 and 1005+100. The

corresponding amount of earthworks should be greatly reduced in comparison to option 1.

Between Sta. 1005+400 and 1005+800

The unmitigated EIL is located on the far left (northwest) side of the new highway alignment. The road

grade in this area is at about 470 m elevation and is in small cuts and fills. If unmitigated an erosion slope

approximately 8 m high could develop which would compromise the global stability of the new highway

grade. Nearby boreholes indicate the area is underlain predominantly by silt and clay. Recommendations

for erosion mitigation include two options:

1) Excavate riprap into the ground near the toe of the embankment. The required excavation could

be between 4 and 8 m deep and the riprap would need to protect a 5H:1V slope geometry to

maintain stability of the road. Excavation and riprap placement would likely need to be carried out




prior to construction of the roadway prism, and the riprap may need to be buried depending on

future land use. It is considered that the volume of excavation for this option would be onerous.

2) Place riprap on the current ground surface close to the reservoir shoreline. The corresponding

amount of earthworks should be greatly reduced in comparison to option 1.

Between Sta. 1005+860 and 1006+000

The unmitigated EIL is located on the far left (northwest) side of the new highway alignment. The new

highway is in a small fill. The reservoir shoreline intersects the natural slope below the fill slope. Erosion of

the natural slope would undermine the fill slope. It is recommended that erosion mitigation is to extend

riprap down the natural slope.

Settlement Analyses

Settlement analyses were carried out for fills corresponding with culvert locations. Culvert locations,

culvert diameters, culvert lengths, approximate maximum embankment height and approximate

maximum depth to culvert invert from top of embankment are summarized in Table 9-1, below.

Table 9-1: Culvert Locations and Descriptions

Location Diameter (m) Length (m) Embankment

Height (m)

Depth to Culvert

Invert (m)

Sta. 1004+430 0.9 61.5 5 5

Sta. 1004+812 2.4 27.5 3 3

Sta. 1005+075 1.2 42.5 4 4

Sta. 1005+285 1.2 57.0 8 5

Sta. 1005+487 0.2 54.0 4 4

Sta. 1005+820 1.6 37.5 5 4

Sta. 1006+180 1.2 41.0 10 5

Sta. 1006+450 1.2 43.0 15 5

Sta. 1006+500 2.7 42.0 15 7

Sta. 1006+658 0.9 36.0 24 4

Sta. 1006+900 0.9 31.5 8 3

Sta. 1007+055 2.4 33.5 5 5

Settlement analyses considered:

1) Stress history of the soil;

2) Soil compressibility Parameters; and

3) Stress distribution below the embankment.

Settlement was calculated for granular soil layers using the stress-strain modulus method and for

cohesive soil layers using the consolidation method.

Soil Stress History

The valley bottom sediments below the new highway alignment likely consist of younger, post-glacial,

granular fluvial channel, terrace deposits, fine-grained (silt/clay) over-bank flood plain deposits, and

colluvial sediments derived from adjacent valley slopes. As determined by the CPT, the stress history of

these deposits is variable with measured over consolidation ratios (OCR) between 1 and greater than 10.

These deposits are interpreted to have been deposited after the last glacial advance and have therefore




not experienced loading from glacial ice. The observed pre-consolidation could be the result of

fluctuations of the water table, erosion of sediments, and ice and snow loads. Pre-consolidation can also

be produced by desiccation, freezing and thawing, and chemical changes caused by oxidation.

Based on the variability of the OCR measured by the CPT, and the potential mechanisms that caused the

pre-consolidation it is anticipated that the stress history of the soil is spatially variable. For the purpose of

the settlement analyses, the stress history of cohesive soil layers has been interpreted from nearby CPT

locations and granular soil layers are assumed to be normally consolidated.

Soil Compressibility Parameters

Granular Soil

Settlement of granular soils was calculated using a stress-strain modulus, Es. The stress strain modulus

was estimated using a correlation with the SPT ‘N’ value (Bowles, 1996).

𝐸𝑠 = 500 × (𝑁 + 15)

Where:

𝐸𝑠 = Stress strain modulus

𝑁 = determined from the Standard Penetration Test and based on a hammer energy level of 55%

Cohesive Soil

Settlement of cohesive soils was calculated using the results of a laboratory incremental load

consolidation test and a correlation using the Atterberg liquid limit. The results of the consolidation test

are summarized in Table 9-2, below.

Table 9-2: Results of Incremental Load Consolidation Test

A correlation by Terzaghi and Peck (1967), with a reported error of +/- 30%, was used to estimate the

compression index.

𝐶𝑐 = 0.009(𝑤𝑙 − 10)

Where:

𝐶𝑐 = Compression Index

𝑤𝑙= Atterberg liquid limit

Using the liquid limit noted in Table 9-2, the correlation predicts a compression index of 0.24 which is

comparable to the laboratory determined compression index of 0.23.

The recompression index (Cr) is estimated at 20% of the compression index.

The compression index was estimated using an average of liquid limits from samples in the vicinity of the

culverts. The number of test results used to determine the average, the minimum and maximum values,

and the estimated compression and recompression indices are summarized in Table 9-3.

Location Depth Soil Unit Liquid

Limit

Plastic

Limit

Plasticity

Index

Compression

Index

TH19-LX-218 1.8 m CL 37% 18% 19% 0.23




Table 9-3: Estimated Compression and Recompression Indices

Culvert

Location

Number of

Atterberg Tests

Liquid Limit (%) Estimated

Compression

Index (Cc)

Estimated

Recompression

Index (Cr) Min. Max. Ave.

Sta. 1004+430 10 33 51 41 0.28 0.06

Sta. 1004+812 5 30 39 32 0.20 0.04

Sta. 1005+075 2 30 41 36 0.23 0.05

Sta. 1005+285 9 36 57 46 0.32 0.06

Sta. 1005+487 6 35 44 39 0.26 0.05

Sta. 1005+820 14 20 44 29 0.17 0.03

Sta. 1006+180 7 25 44 33 0.21 0.04

Sta. 1006+450 2 27 40 34 0.22 0.04

Sta. 1006+500 5 20 55 38 0.25 0.05

Sta. 1006+658 2 33 36 35 0.23 0.05

Sta. 1006+900 4 28 38 35 0.23 0.05

Sta. 1007+055 1 22 22 22 0.11 0.02

Embankment Stress Distribution

The embankment will impose a stress increment in the underlying soil. The stress increment was

estimated by converting the cross-sectional area of the embankment into a rectangle with an

approximate equivalent area. The height of the equivalent rectangle is approximately the same height as

the embankment at road centerline. The top and bottom of the rectangle is horizontal. The rectangle is

assumed to infinitely long along the centerline of the highway alignment. The stress increment was

calculated below the rectangle by assuming a 2.0V:1.0H load distribution.

Settlement Estimates

Using the information noted above, settlement was estimated at culvert locations. The estimate

corresponds to settlement below the centerline of the new highway alignment. In most cases settlement

at the inlet and outlet of the culverts will be significantly less than settlement below the highway

centerline. The estimates include immediate settlement of granular soils as determined by the stress-

strain modulus method, and consolidation settlement of cohesive soils as determined by the

consolidation method. By the end of application of full static load (soon after the end of construction), the

majority of immediate settlement may have occurred; however, only a fraction of consolidation settlement

will have occurred. The results of the settlement estimates are summarized in Table 9-4.




Table 9-4: Estimated Settlement at Culvert Location, below Road Centerline

Culvert

Location

Embankment

Height (m)

Effective

Embankment

Width (m)

Immediate

Settlement

(m)

Consolidation

Settlement

(m)

Total

Settlement

(m)

Sta. 1004+430 5 40 0.01 0.20 0.21

Sta. 1004+812 3 25 0.03 0.08 0.11

Sta. 1005+075 4 30 0.01 0.09 0.10

Sta. 1005+285 8 35 0.02 0.14 0.16

Sta. 1005+487 4 35 0.04 0.03 0.07

Sta. 1005+820 5 35 0.01 0.17 0.18

Sta. 1006+180 10 40 0.01 0.31 0.32

Sta. 1006+450 151 55 0.06 0.60 0.662

Sta. 1006+500 151 40 0.06 0.39 0.452

Sta. 1006+658 101 65 0 0.42 0.422

Sta. 1006+900 51 25 0.01 0.38 0.392

Sta. 1007+055 51 30 0.10 0 0.102 Note: 1 Average height relative to existing highway grade and RHS slope. Does not include height above in-stream platform which

is assumed to be relatively incompressible. 2 The presence of existing highway fill, disturbed slide debris and side cast fill below the new embankment fill in these areas

increases the error of the settlement estimates. Actual settlement could be greater than presented above.

Differential settlement was estimated assuming the ends of the culverts will not settle relative to highway

centerline (i.e. middle of the culvert). This assumption may be overly conservative for culverts located near

the top of high embankments. Estimated differential settlement is summarized in Table 9-5.




Table 9-5: Estimated Differential Settlement along Culverts

Location

Distance

between Middle

and End of

Culvert, L (m)

Settlement

at Middle of

Culvert, δ

(m)

Differential

Settlement,

δ/L

Comments

Sta. 1004+430 31 0.21 0.007 Located at base of embankment on natural ground subgrade.

Sta. 1004+812 14 0.11 0.008 Located at base of embankment on uniform subgrade.


Sta. 1005+285 29 0.16 0.006 Inlet located at base of embankment on natural ground, outlet on

embankment fill.


Sta. 1005+820 19 0.18 0.009 Inlet located at base of embankment on natural ground, outlet on

embankment fill.

Sta. 1006+180 21 0.32 0.015 Located near mid-height of embankment. Differential settlement likely less

than estimate.

Sta. 1006+450 22 0.66 0.0301

Located near top of embankment. LHS located above existing fill of unknown

compressibility, RHS located above in-stream platform. Differential settlement

may exceed estimate.

Sta. 1006+500 21 0.45 0.0211

Located near mid-height of embankment. LHS located above existing fill of

unknown compressibility, RHS located above in-stream platform. Differential

settlement may exceed estimate.

Sta. 1006+658 18 0.42 0.0231

Located near top of embankment. Far LHS located above existing fill of

unknown compressibility, center and RHS located above in-stream platform.

Differential settlement may be a concern near inlet.

Sta. 1006+900 16 0.39 0.0241

Located near top of embankment. LHS and center located above existing fill

of unknown compressibility, far RHS located above in-stream platform.

Differential settlement may be a concern near outlet.

Sta. 1007+055 17 0.10 0.0061

Inlet located at base of embankment on natural ground, outlet on

embankment fill over existing fill of unknow compressibility. Differential

settlement may be a concern near outlet. Note: 1 The presence of existing highway fill, slide debris and side cast fill below the new embankment in these areas increases the error of the differential settlement estimates.

Actual differential settlement could be greater than presented above.




Time Rate of Consolidation

The time rate of consolidation settlement is a function of the rate of dissipation of the excess pore

pressures (which in turn is a function of the length of the drainage path in the consolidating layers),

coefficient of consolidation, lateral extent of loading, presence and horizontal continuity of coarse-grained

interbedding layers (drainage layers), and other factors dependent on local conditions. Given the

asymptotic nature of the pore pressure dissipation process, the end of primary consolidation settlement is

generally considered to be the time it takes to complete 95% of the primary consolidation settlement.

The results from the laboratory incremental load consolidation test yielded a coefficient of consolidation

of approximately 6 m2/year, it is anticipated that the coefficient of consolidation will vary depending on

the soil unit. Coefficients of consolidation of 4 and 10 m2/year were also considered in estimating time

rate of consolidation. The estimated time rate of consolidation is summarized in Table 9-6, below.

Table 9-6: Time Rate of 95% Consolidation Considering Two-Way Drainage

Consolidating

Layer Thickness

(m)

Time Rate of 95% Consolidation1

Cv = 4 m2/year Cv = 6 m2/year Cv = 10m2/year

1 1 month 0.5 month 0.3 month

2 3 months 2 months 1 month

4 13 months 9 months 5 months

6 30 months 20 months 12 months Note: 1 Assumed two-way drainage

Based on the CPT profiles, it appears that consolidating layers are interbedded with drainage layers,

resulting in relatively short drainage paths and consequently relatively rapid drainage of excess pore

pressures. Considering a consolidating layer thickness of 1 m and a coefficient of consolidation of

6 m2/year, approximately 0.5 months may be required for 95% of consolidation settlement to occur;

however, the time could vary depending on the coefficient of consolidation layer thickness. In order to

mitigate settlement effects, embankment fills should be constructed as far in advance of settlement

sensitive structures (e.g. culverts and final pavement structure) as is feasible within the project schedule.

At some culvert locations a staged construction methodology or a preload is required to mitigate

settlement, as described in Section 10.0. Instrumentation (in the form of settlement plates and

piezometers as described in Section 0) will be used to monitor settlement rates and inform timing of

completion settlement sensitive structures.

Secondary Compression Settlements

Secondary compression may occur after initial consolidation of the cohesive soil layers. Due to the

variable stress history of the soil deposit it is difficult to estimate the magnitude of secondary

compression. It is anticipated that secondary compression will be relatively small for soils that remain in

recompression and somewhat larger for soils in virgin compression. Differential settlement from

secondary compression is not anticipated to be a concern.

Settlement of Existing Fill

New embankment fill will be located above existing highway fill between approximately Sta. 1006+020

and the end of the segment (Sta. 1007+280), the embankment will also cover existing slides and slide

debris, and side cast fill on the RHS slope down to the river. The top of the new embankment is up 15 m

above the existing highway surface, and up to 20 m above the RHS slope down to the river. Although

settlement has been estimated in this area (see Table 9-4), the variability of the existing fill, slide debris




and side cast fill will increases the error of the settlement estimates, and actual settlement could be

greater than presented in Section 9.6.

However, some settlement could occur during construction of the embankment and prior to the

embankment height achieving the invert elevation of the culverts. Any settlement that occurs during

construction of the embankment and before construction of the culverts would offset the total theoretical

amount of settlement experienced by the culverts.

Although significant zones of organic soil or organic debris were not encountered during the site

investigation these zones may be present between the boreholes, or on the slope down to the river. Long-

term settlement can occur when the organic soil or debris decomposes and consolidates. If zones of

organic soil or organic debris are encountered during construction, the organic soil and debris should be

excavated and removed from below the embankment.

Sub-excavation of existing highway fills and existing slide debris can be considered if it is desirable to

reduce settlement; however, it may be onerous and impractical to remove significant volumes of existing

fill. Other mitigations could include:

1) Partial excavation of the fill and slide debris;

2) Use geogrid to bridge or distribute settlement over a larger area;

3) Construct as much of the grade as soon as possible, monitor the grade for settlement, and

compensate for any settlement prior to installing culverts and the final highway surface.

Note that in general excavation of existing highway fill and slide debris is not required for slope stability

objectives.

Settlement Mitigation

It is understood the criteria for differential settlement along a corrugated steel pipe culvert is limited to

the lesser of 1% of the culvert length or 0.15 m. As all culvert lengths are greater than 15 m, the limiting

factor is the settlement criterion of 0.15 m. Based on this criterion nine culvert locations require mitigation

to reduce the amount of anticipated differential settlement; these locations are summarized in Table 10-1.

Table 10-1: Estimated Differential Settlement and Settlement Criterion

Location Settlement at Middle of Culvert,

δ (m)

Exceeds Differential Settlement

Criterion of 0.15 m

Sta. 1004+430 0.21 Yes

Sta. 1004+812 0.11 No

Sta. 1005+075 0.10 No

Sta. 1005+285 0.16 Yes

Sta. 1005+487 0.07 No

Sta. 1005+820 0.18 Yes

Sta. 1006+180 0.32 Yes

Sta. 1006+450 0.66 Yes

Sta. 1006+500 0.45 Yes

Sta. 1006+658 0.42 Yes

Sta. 1006+900 0.39 Yes

Sta. 1007+055 0.10 Yes1 Note: 1 The presence of existing highway fill, potentially decomposable slide debris, and side cast fill below the new

embankment in this area results in unreliable estimates of differential settlement using conventional consolidation

settlement analysis methods. Actual differential settlement could be greater than presented above. For design purposes it

is assumed differential settlement could exceed 0.15 m.




Where the differential settlement criterion is exceeded, settlement can be mitigated by using a staged

construction methodology or by preload. A staged construction methodology would involve constructing

the embankment up to the culvert invert elevation for a distance of 30 m on either side of the culvert axes

and monitoring for settlement. Once sufficient settlement has occurred such that the anticipated residual

settlement is less than 0.15 m the culvert can be installed, and the remaining embankment constructed. A

preload would involve initial placement of the embankment fill (using temporary culverts as needed) to

the final highway design grade for a distance of 30 m on either side of the culvert axes and monitoring for

settlement. Once sufficient settlement has occurred such that the anticipated residual settlement is

estimated to be less than 0.15 m the preload can be removed and the permanent culvert installed. Note

that preload fill that will be left in place after culvert installation must meet the gradation and compaction

requirements for the design location it is left in. The recommended mitigation for each culvert location

that exceeds the differential settlement criterion is summarized in Table 10-2. The estimated potential

minimum time for settlement abatement to occur (i.e. when residual settlement is estimated to be less

than 0.15 m) is also included in Table 10-2.

Table 10-2: Settlement Mitigation

Location Settlement Mitigation Potential Minimum Time Required for

Settlement Abatement

Sta. 1004+430 Preload 6 Weeks

Sta. 1005+285 Staged Construction 4 Weeks








East of Station 1006+000 Binnie provided a suggested three stage embankment construction approach to

accommodate traffic during construction (Binnie, 2020). For the culvert at Sta. 1006+180 the staged

culvert construction can occur during Binnie’s suggested Stage 2 Construction and using the Stage 2

Construction cross section. For the culvert at Station 1007+055 the staged culvert construction approach

can occur during Binnie’s suggested Stage 1 Construction. For the culverts at Stations 1006+450,

1006+500, 1006+658, and 1005+900 the preload can occur during Binnie’s suggested Stage 2

Construction and using the Stage 2 Construction cross section.

Instrumentation

During construction of the embankments it is recommended that monitoring of ground movements,

settlement and groundwater pressures be carried out.

Slope Inclinometer Casing

Slope inclinometer casings are proposed at the toe of high embankment slopes that are underlain by

cohesive soils. The slope inclinometer casings will be monitored during construction to check for lateral

deformation within the cohesive soil. The bottom portion of the slope inclinometer casings will be

installed in bedrock. Slope inclinometer casings are proposed at the locations noted in Table 11-1.




Table 11-1: Slope Inclinometer Casings

Location Offset Target Elevation at Bottom of Casing

Sta. 1004+380 30 m Right 454 m

Sta. 1005+280 47 m Right 451 m

Sta. 1005+280 30 m Left 451 m

Sta. 1005+840 62 m Right 444 m

Settlement Plates

Settlement plates are proposed for culvert crossing embankments where settlement monitoring for

staged construction or preload is recommended. Each settlement plate will consist of a horizontal plate

located at the base of the embankment and a vertical riser pipe that extends up through the

embankment. Settlement plates are proposed at the locations noted in Table 11-2.

Table 11-2: Settlement Plates

Location Offset

Sta. 1004+420 7 m Right1

Sta. 1004+430 7 m Left

Sta. 1005+280 5 m Right1

Sta. 1005+280 25 m Right

Sta. 1005+815 10 m Right1

Sta. 1005+815 25 m Right

Sta. 1006+185 5 m Left

Sta. 1006+185 5 m Right1

Sta. 1006+455 5 m Left

Sta. 1006+455 5 m Right1

Sta. 1006+505 5 m Left1

Sta. 1006+505 5 m Right

Sta. 1006+653 15 m Left

Sta. 1006+653 5 m Right

Sta. 1006+895 5 m Left

Sta. 1006+895 5 m Right

Sta. 1006+895 15 m Right

Sta. 1007+050 20 m Right

Note: 1 Settlement plate co-located with a vibrating wire piezometer

Vibrating Wire Piezometers

Vibrating wire piezometers are proposed to be paired with settlement plates at culvert crossing

embankments where either staged construction or preload is recommended. The vibrating wire

piezometers will be used to measure pore pressures in cohesive soil layers during construction of the

embankments. Vibrating wire piezometers are proposed at the locations noted in Table 11-3. Note that all

vibrating wire piezometers are co-located with a settlement plate.




Table 11-3: Vibrating Wire Piezometers

Location Offset Piezometer Tip Target Elevation

Sta. 1004+420 7 m Right 460 m

Sta. 1005+280 5 m Right 455 m

Sta. 1005+815 10 m Right 457 m

Sta. 1006+185 5 m Right 456 m

Sta. 1006+455 5 m Right 450 m

Sta. 1006+505 5 m Left 455 m

Large Diameter Culvert Headwalls

Custom designed cast-in-place reinforced concrete headwalls are required at five locations and a custom

designed reinforced concrete outlet collar is required at one location. The locations of the custom

designed headwalls and outlet collar are provided in Table 12-1. At other locations standard BCMoTI pre-

cast concrete headwall designs will be used.

Table 12-1: Headwall and Collar Locations, and Pipe Diameter

Location Pipe Diameter (m) Structure

Sta. 1002+4651 2.0 Headwall


Sta. 1005+285 1.2 Collar



Sta. 1007+055 2.4 Headwall Note: 1 Located in the Lynx West Segment

Subgrade Conditions

A summary of anticipated subsurface conditions at each structure location is provided in Table 12-2.

Table 12-2: Summary of Subsurface Conditions at Headwall and Collar Locations

Location

Subgrade Conditions Fill Height

above

Culvert

Embankment Slope

Comment Inlet Outlet Inlet Outlet

Sta. 1002+4651 Silt Silt 4 m 2H:1V 2H:1V In cut

Sta. 1004+812 Silt and silty

sand

Silt and silty

sand 2 m 3H:1V 3H:1V

Scratch

grade

Sta. 1005+285 Clay

3 m

embankment

fill

4 m 4H:1V 4.25H:1V

Scratch

grade / in

fill

Sta. 1005+487 Clay Clay 2 m 3H:1V 3H:1V Scratch

grade

Sta. 1006+500

7 m

embankment

fill

20 m

embankment

fill

4 m 2H:1V 3H:1V2 In fill

Sta. 1007+055

Silty gravel

and silty

sand

5 m

embankment

fill

2 m 2H:1V 3H:1V2

Scratch

grade / in

fill Note: 1 Located in the Lynx West Segment

2 Right-hand side fill slope to be confirmed after in-river platform built and additional investigation and analyses carried out




Note that the right-hand side (outlet) fill slope at Sta. 1006+500 and 1007+055 will not be finalized until

an investigation and additional slope stability analyses are carried out upon completion of the in-river

early works platform for the fill.

Soil Bearing Capacity

To calculate the soil bearing capacity it was assumed the headwalls and apron slabs are approximately 4

by 6 m in plan and embedded a minimum of 0.3 m into the surrounding soil. The culvert collar at Sta.

1005+820 is assumed to be 1.8 by 0.3 m in plan and embedded a minimum of 0.9 m into the surrounding

soil. Note that soil bearing capacity will increase for larger plan areas and embedment depths. Based on

the assumed foundation configurations noted above, factored ultimate geotechnical bearing capacities

were calculated and summarized in Table 12-3. The factored ultimate bearing capacity includes a

geotechnical resistance factor, Φ = 0.55. Note that a minimum 0.5 m thick pad of compacted Clean

Granular Fill (as defined in Section 13.3) is required below the headwalls. Where the subgrade surface

below the pad of Clean Granular Fill is fine-grained (e.g. clay, silt, silty sand), the subgrade is to be lined

with a Class 2 non-woven geotextile as defined in Section 13.7. Fine-grained subgrades are anticipated at

Sta. 1004+465, 1004+812, 1005+487, 1007+055 (inlet only).

Table 12-3: Factored Ultimate Bearing Capacities

Location

Factored Ultimate Bearing

Capacity (kPa) Assumed Subgrade Conditions

Inlet Outlet

Sta. 1002+4651 70 kPa 70 kPa Minimum 0.5 m pad of compacted Clean Granular

Fill, over silt


Fill, over silt and silty sand

Sta. 1005+285 N/A 160 kPa ~3 m embankment thickness of compacted Clean

Granular Fill, over clay


Fill, over clay

Sta. 1006+500 160 kPa 160 kPa

>3 m embankment thickness of Clean Granular Fill

at inlet and outlet; assumed embankment slope of

2H:1V

Sta. 1007+055 160 kPa 160 kPa

Minimum 0.5 m pad of compacted Clean Granular

Fill at inlet, over silty gravel; >3 m embankment

thickness of Clean Granular Fill at outlet; assumed

embankment slope of 2H:1V Note: 1 Located in the Lynx West Segment

It is anticipated that differential settlement between the headwall and the culvert will not exceed 25 mm

unless the factored ultimate limit states bearing capacity is exceeded. Note that staged construction and

preloading will occur at some culvert locations which will further reduce the potential for differential

settlement between the headwall and culvert.

Frost Design Considerations

Based on past experience in the area, Wood anticipates that frost could penetrate approximately 3 m

below ground surface. Because the headwalls and culverts will be exposed to freezing temperatures the

depth of frost penetration should be measured from the underside of the headwall and culvert invert.




The natural clay, silt and silty sand soils below the headwalls and culverts are susceptible to frost heave.

To reduce the potential for differential frost heave between the headwall and the culvert, Wood

recommends using a consistent subgrade surface below both the headwall and culvert.

However, if it is desirable to reduce frost heave altogether, Wood recommends replacing the soil below

the headwall and culvert with Clean Granular Fill extending at least 3 m below the underside of the

headwall and culvert invert. An alternative to fully replacing the soil below the headwall and culvert with

Clean Granular Fill is to protect the underlying soil from freezing by using rigid board insulation. The rigid

board insulation would be placed below the headwall and culvert and extend laterally out by

approximately 3 m. If required, a detail for using rigid board insulation (including thickness and strength

of rigid board insulation) can be developed by Wood.

Lateral Earth Pressures

Earth pressures against the headwalls can be calculated using the earth pressure coefficient specified in

Table 12-4. Active earth pressure coefficients apply to flexible retaining structures capable of displacing at

least 1% of the net retained height. For all other structures, use the at-rest case. Retaining structures are

assumed to be backfill with Clean Granular Fill with a friction angle of 38°.

Table 12-4: Earth Pressure Coefficients under Static Condition for Various Sloping Conditions

Earth Pressure

Case

Static Condition

Flat 4.25H:1V1 4H:1V1 3H:1V1 2H:1V1

Active 0.24 0.27 0.27 0.29 0.33

At-rest 0.38 0.47 0.48 0.51 0.56

Passive 4.20 7.00 7.24 8.85 13.80 Note: 1Slope is measured from horizontal and upward and away from structure

For calculating lateral earth pressure use a bulk unit weight of 21 kN/m3 for Clean Granular Fill backfill.

Backfill behind the structure should not be placed before the structure concrete has adequate strength.

Compaction of backfill within 2 m of the wall should be in maximum 0.10 m thick lifts using a walk behind

plate compactor. To take into account the increase lateral earth pressure due to compaction, increase the

calculated lateral earth pressure by at least 12 kPa.

Sliding Friction Coefficient

Resistance of shallow foundations to horizontal loads may be determined using a concrete-soil interface

friction angle of 25° for cast in-place or precast concrete founded on Clean Granular Fill. Sliding resistance

determined based on this interface friction angle is an unfactored resistance, which can be calculated by

multiplying the sum of the vertical forces that are exerted on the footing by the tangent of the concrete-

soil interface friction angle provided above. The factored resistance against sliding may be determined by

applying a resistance factor.

General Recommendations

The following section provides geotechnical recommendations that are generally applicable for the design

and construction of the new highway alignment.

Stripping

Stripping will be required below all foundation subgrades. Approximate stripping depth by project station

are summarized in Table 13-1.




Table 13-1: Stripping Depths by Station

Location Stripping

Depth (m) Comments

1004+330 to 1004+660 0.2 -

1004+660 to 1004+780 0.1 -

1004+780 to 1004+840 0.2 -

1004+840 to 1004+900 0.1 -

1004+900 to 1005+460 0.2 -

1005+460 to 1005+500 0.2

Potential to encounter existing site disturbance (e.g. disturbed soil, fill, buried debris) from previous

land use. Sub-excavation may be required if site disturbance is encountered during subgrade

review.

1005+500 to 1005+690 0.2 -

1005+690 to 1005+910 0.6

RHS, potential to encounter existing site disturbance (e.g. disturbed soil, fill, buried debris) from

previous land use. Sub-excavation may be required if site disturbance is encountered during

subgrade review.

1005+910 to 1005+970 0.6 -

1005+970 to 1006+120 0.8 -

1006+120 to 1006+210 0.6 -

1006+210 to 1006+780 RHS 0.1

LHS 0.3

RHS, if organic soil or organic debris is identified during construction review, sub-excavation of

organic soil or organic debris will be required.

RHS, existing slide between Sta. 1006+380 and 1006+460, optional sub-excavation to reduce

settlement to overlying embankment fill, sub-excavation not required for stability objectives.

1006+780 to 1006+860 0.3 RHS, if organic soil or organic debris is identified during construction review, sub-excavation of


1006+860 to 1007+030 0.3

RHS, if organic soil or organic debris is identified during construction review, sub-excavation of


RHS, existing historically remediated slide between Sta. 1006+780 and 1006+900, optional sub-

excavation to reduce settlement to overlying embankment fill, sub-excavation not required for

stability objectives.

RHS, existing not remediated, recently active slide between Sta. 1006+900 and 1007+030, optional

sub-excavation to reduce settlement to overlying embankment fill, sub-excavation not required for

stability objectives.




Location Stripping

Depth (m) Comments








In addition to the stripping depths noted above, deeper stripping and/or sub-excavation will be required

if deleterious soils (e.g. soft, wet, weakened, and organic soils or loose fill) are encountered. All stripped

foundation subgrades should be reviewed by a geotechnical engineer or their representative to confirm

that deleterious soils have been removed prior to fill placement.

It is recommended that the existing asphalt surface be removed below the footprint of new embankments

and that the underlying gravel surface be scarified prior to placement of embankment fill. Approximate

asphalt thicknesses are noted in Section 6.0.

Subgrade Preparation

The following subgrade preparation procedure is recommended for general highway construction.

1) Remove all deleterious soils (e.g. soft, wet, weakened, and organic soils or loose fill) from the

subgrade surface. A geotechnical engineer or their representative should review subgrade

surfaces to confirm that deleterious soils have been removed.

2) As soon as possible following exposure of a fine-grained subgrade crown the subgrade surface

with a minimum cross fall of 2% to promote drainage. This will help minimize softening of the

subgrade surface due to ponding and infiltration of surface water. Note that the subgrade surface

must have a 2% cross fall prior to placement of SGSB.

3) For fine-grained subgrades, minimize disturbance of the subgrade surface by limiting vehicle and

construction traffic over the prepared subgrade surface. If the subgrade surface becomes

disturbed and softened, removal of the softened soil and replacement will fill similar the

surrounding subgrade will be required.

4) Areas of unsuitable subgrade soils that are determined to be too deep to be practically removed

will require additional subgrade improvements as directed by a geotechnical engineer at the time

of construction. Subgrade improvements may consist of (but are not limited to) use of a

geotextile separator, biaxial geogrid layers(s), granular backfills and/or other methods.

Embankment Fill Construction

The following general recommendations are provided for embankment fill construction.

1) All fill foundation preparation, fill placement and fill compaction operations should be observed

by qualified geotechnical engineering field personnel to confirm that that construction is in

accordance with the recommendation in this report and BCMoTI Standard Specifications (2016).

2) Existing deleterious soils (e.g. soft, wet, weakened, and organic soils or loose fill) should be

removed from under the footprint of the embankment and from the outside face of existing

highway fill slopes prior to placing new fill.

3) Fill material should consist of inorganic granular soil with moisture content near (+/- 1%) of the

optimum moisture content for compaction, as determined by laboratory moisture-density testing.

In general, the following two granular fill types are recommended.

a) Clean Granular Fill (CGF) – to be used for all embankment and/or berm fills located below an

elevation of 466 m, and the lower and back 1 m of fills placed on or against groundwater

seepage zones.

- CGF is to be free of organics and other detritus.

- CGF is to have less than 5% particles passing the 0.075 mm sieve.

-CGF can have particle sizes up to 300 mm, provided adequate lift thickness and compaction

is achieved before placement of the next lift. The construction contractor must demonstrate

via test strips and test excavations that they have the equipment and methodology to achieve

a compaction nominally equivalent to 95% Standard Proctor Maximum Dry Density (ASTM




D698), with no observable segregation or deflection and no rutting greater than 10 mm

under construction traffic loading.

b) Type D Granular Fill (Type D) – to be used for all other fill locations, except along the lower

and back 1 m of fills placed on or against groundwater seepage zones.

- Type D is to be free of organics and other detritus.

- Type D material gradation shall meet BCMoTI Standard Specification (2016), Section 201.44

and consist of predominately granular material that contains a maximum of 20% particles

passing the 0.075 mm sieve.

- Type D can have particle sizes up to 300 mm, provided adequate lift thickness and

compaction is achieved before placement of the next lift. The construction contractor must

demonstrate via test strips and test excavations that they have the equipment and

methodology to achieve a compaction nominally equivalent to 95% Standard Proctor

Maximum Dry Density (ASTM D698), with no observable segregation or deflection and no

rutting greater than 10 mm under construction traffic loading.

4) Fill that will overlie groundwater seepage zones (from either natural or existing fill slopes) will

require field review by a geotechnical engineer. These areas should be treated on a case by case

basis. A conceptual treatment could be placement of a granular drainage blanket from the base

of the excavation to a minimum 2 m above the seepage area. The granular drainage blanket

would need to be separated from adjacent material using a non-woven geotextile (as defined in

Section 13.7).

5) Fills underlain by groundwater seepage zones should be covered by a minimum 1 m thick layer of

CGF, the top of the CGF layer should extend at least 0.5 m above the high-water mark of any

standing water, or at least 0.5 m above the adjacent original ground surface. A non-woven

geotextile should be placed on the prepared subgrade before placement of the CGF. A layer of

non-woven geotextile should be placed over the CGF layer where Type D will be placed over the

CGF.

6) Drainage from under an embankment area should be directed to an exposed face of a ditch or a

sub-drain system but should not be directed over the face of potentially unstable or erodible

slopes without additional armoring and/or riprap.

7) At the transition sections between the new highway embankment and existing embankment

(approximately between Sta. 1007+100 and 1007+280), positive subsurface drainage away from

the existing highway embankment is to be maintained. New fills places near granular fills below

the existing highway should be constructed with CGF and extend a minimum 0.1 m below the

underside of the existing granular fill so as not to block internal drainage.

Cut Slope Construction

The following general recommendations are provided for cut slope construction.

1) Cut slopes that encounter seepage must be reviewed by a geotechnical engineer and may need

to be protected from piping erosion by the placement of a granular drainage blanket on the face

of the slope from the base of the ditch to a minimum 2 m above the seepage zone.

2) Fine-grained cut materials are unsuitable for re-use and should be considered waste.

3) Cut areas should be hydroseeded with an appropriate vegetation seed mix as soon as possible

after soil disturbed is finished.

Temporary Excavations

Temporary excavations greater than 1.2 m in depth, where worker entry is required, should be constructed

in accordance with the current Part 20.78 through 20.95 of the Occupational Health and Safety Regulation

as per WorkSafeBC. The construction contractor is ultimately responsible for the safety of temporary




excavation slopes. Should excavations encounter groundwater, flatter slopes than those recommended by

WorkSafeBC could be required. Excavations greater than 1.2 m in depth with steeper slopes and those

subject to seepage or sloughing should not be entered unless they are shored, braced or sloped as

approved by the contractor’s geotechnical engineer.

Temporary excavations and construction work will be required below steep and unstable slopes,

particularly along the in-stream stability berm (L2 alignment). The construction contractor is responsible

for developing safe work procedures to carry out work below all slopes.

Culverts and Headwalls

The following general recommendations are provided for installing culverts.

1) Excavated and remove all deleterious soils (e.g. soft, wet, weakened, and organic soils or loose fill)

from below the proposed culvert bedding subgrade.

2) If the culvert bedding subgrade surface is fine-grained, a non-woven geotextile separator (as

defined in Section 13.7) will be required between the bedding material and the fine-grained

subgrade.

3) Use culvert bedding material that meets BCMoTI Standard Specifications, Section 303.

Where culverts have headwalls, the headwall foundation should be founded on a minimum 0.5 m thick

layer of compacted CGF that extends down from the outside edge of the foundation at 1H:1V to a

subgrade bearing surface that is approved by a geotechnical engineer. Where the subgrade surface is

fine-grained, a non-woven geotextile separator will be required between the compacted CGF and the

fine-grained subgrade.

Geotextile and Biaxial Geogrid Specifications

Where non-woven geotextiles are required, the recommended specifications are provided in Table 13-2.

Table 13-2: Non-Woven Geotextile Specifications

Note: 1 Elongation > 50%, as per ASTM D4632 2 Based on minimum average roll values (as per ASTM C 4759) in the weaker principal direction 3 Based on maximum average roll values

Property Test Method Class 1 Class 2

Material Type Non-Woven1 Non-Woven1

Grab Tensile Strength2 ASTM D 4632 ≥ 900 N ≥ 700 N

Sewn Seam Strength2 ASTM D 4632 ≥ 810 N ≥ 630 N

Tear Strength2 ASTM D 4533 ≥ 350 N ≥ 250 N

Puncture Strength2 ASTM D 6241 ≥ 1925 N ≥ 1375 N

Permittivity ASTM D4491 ≥ 0.2 sec-1 ≥ 0.1 sec-1

Apparent Opening Size3 ASTM D 4751 < 0.43 mm < 0.22 mm

Recommended Application > 50 kg class riprap

Drainage layers

Subgrade separation

< 50 kg class riprap




Where geogrid is required for local subgrade improvement during construction, the recommended

specification for a biaxial polypropylene geogrid are provided in Table 13-3.

Table 13-3: Biaxial Polypropylene Geogrid Specifications

Property Test Method Value

Tensile Strength @ 5% Strain, Machine Direction1 ASTM D 6637 ≥ 11.8 kN/m

Tensile Strength @ 5% Strain, Cross Machine

Direction1 ASTM D 6637 ≥ 18.8 kN/m

Maximum Aperture Size 50 mm

Minimum Aperture Size 15 mm

Flexural Stiffness1 ASTM D 7748 ≥ 700 g-cm

Roll Width +/- 0.1 m

Note: 1 Based on minimum average roll values (as per ASTM C4759).

Pavement Structure

The recommended pavement structure is dependent on the nature of the soil subgrade that will be

encountered (in cuts) or constructed (fills). Table 13-4 provides recommended pavement structures for the

new highway alignment for two different subgrade conditions: Type A for well-drained granular

subgrades, and Type B for poorly drained and/or fine-grained subgrades.

Table 13-4: Recommended Minimum Pavement Structure Thickness

Subgrade Type Pavement

Structure Asphalt (AP)

Crushed Base

Course (CBC)

Select

Granular

Subbase

(SGSB)

Well Drained Granular Soils (Sand

and Gravel <10% Fines) A 125 mm 300 mm 300 mm

Poorly Drained or Fine-Grained

Soils (>10% Fines) B 125 mm 300 mm 600 mm1

Note: 1 A non-woven geotextile separator will be required between SGSB and fine-grained subgrades

It is currently anticipated that both Type A and B structures would be used in the highway segment.

Where subgrade fill (embankments) meet the gradation for SGSB the thinner Type A structure would be

used. Where the subgrade is a fine-grained soil the thicker Type B structure would be used. For the Type B

pavement structure, a non-woven geotextile separator will be required below the SGSB. Likely locations

where non-woven geotextile separators will be required are included in Table 13-5.

Table 13-5: Likely Locations for Non-Woven Geotextile Separator below SGSB

Location Anticipated Subgrade

Sta. 1004+660 to 1004+9801 Clayey sand / silt

Sta. 1005+500 to 1005+690 Clay

Sta. 1005+910 to 1005+970 Clay Note: 1 Non-woven geotextile not required on fill around culvert at Sta. 1004+812

Where the new pavement structure abuts the existing structure at the east end of the segment, the new

SGSB thickness should match or exceed that of the existing structure to not hinder drainage.




Soil Waste Disposal

The following procedures are recommended for general siting and placing waste from unsuitable or

surplus soil materials generated by the project. Specific disposal scenarios different from below should be

assessed on a case by case basis by a geotechnical engineer.

1) Waste material should only be placed on slopes with a gradient of 10° (approximately 5.7H:1V) or

less and should not be placed in the vicinity of the crests of other slopes where they could have a

destabilizing influence.

2) Do no site waste areas within or near environmentally sensitive locations such as riparian zones,

seepage zones, or where the waste will cause ponding of water or redirection of drainage

patterns (including ditches).

3) Waste materials should be placed with a maximum slope of 3H:1V and to a maximum height of

3 m. Place the waste in maximum 1 m thick lifts and level with tracked equipment, as required.

4) Where practicable, do not site waste piles adjacent to existing and proposed road fills except for

the designated B8 and B9 disposal sites located between Sta. 1006+060 and 1006+940, described

further in Section 14.0, below. Waste piles placed adjacent to road fills are often encountered

during future road widening and upgrading projects, frequently leading to costly removal during

construction.

5) Waste sites placed adjacent to road fills should not block drainage from existing fills and should

be kept at least 1 m below the proposed road pavement structure subgrade and/or any other

granular fills that are likely to transmit drainage.

6) Contour the waste material to promote surface drainage. To maintain positive drainage from the

fill surface while allow for long-term settlement of the loosely placed fill, use a minimum 10%

cross fall slopes to crown the waste material.

7) Use appropriate short-term measures to control off-site transport of fines in runoff (such as silt

fencing). Maintain the short-term controls until effective long-term measures (such as vegetation

cover) are established.

Subject to relevant environmental and land use requirements, disposal of surplus excavation material

(waste) is not anticipated to be a geotechnical concern, especially if deposited on fluvial terrace areas

and/or below the reservoir inundation level. Surplus material should not be disposed along slope crests or

on slopes steeper than 10°. Waste material should not be disposed of against the toes or sides of granular

(e.g. CGF) fill slopes where internal drainage under static and rapid drawdown conditions is required.

Designated Soil Waste Disposal Sites

Binnie has selected areas for waste deposal. Two large volume areas are located on the LHS of the

alignment between Sta. 1006+060 and 1006+940 and are shown in Figure 2. The large volume area west

of the L15 highway access road is identified as B8 and the large volume area east of the access road is

identified as B9. The areas are generally bound to the south by the new highway embankment and to the

north, east and west by the bottom slopes of the Peace River Valley. Areas B8 and B9 are discussed

further below.




Site B8

Site B8 is located on the LHS of the alignment between Sta. 1006+060 and the L15 highway access road at

Sta. 1006+225. The waste disposal site is bordered to the south by the new highway embankment, to the

east by the L15 highway access road embankment and to the north and west by the existing ground

surface that slopes up from the toe of the highway embankment. The site is approximately 165 m long,

50 m wide and triangular in plan area. The waste soil will extend from approximately 461 m elevation up

to approximately 465 m elevation.

The top surface of the waste material is planar and slopes towards the new embankment at 2%. The top

surface is drained by a 1.2 m diameter culvert located at Sta. 1006+180. It is anticipated that long-term

settlement of the top surface will be greater above the buried toe of the embankment where the waste

soil will be thickest. Long-term settlement may result in the waste surface becoming lower than the

culvert inlet, resulting in areas of standing water.

The slope stability model at Sta. 1006+200 does not consider the effect of the B8 waste disposal area, see

Section 0 and Figures 17 through 19. Steeper LHS embankment fill slopes may be possible once the B8

waste disposal area is considered. Additional stability analyses will be carried out for 100% design.

Site B9

Site B9 is located on the LHS of the alignment between the L15 highway access road at Sta. 1006+225 and

1006+940. The waste disposal site is bordered to the south by the new highway embankment, to the west

by the L15 highway access road embankment and to the north and east by the existing ground surface

that slopes up from the toe of the highway embankment. The site is approximately 715 m long with a

width that generally varies between 30 and 100 m. The waste soil will extend from approximately 453 m

elevation up to approximately 465 m elevation.

The top surface of the waste material is planar and slope towards the new embankment at 2%. The waste

site is located below three separate but coalesced/overlapping alluvial fans that drain onto the waste

surface. Flow from the fans will be drained by three culverts located at Sta. 1006+450, 1006+500 and

1006+658. In general, it is anticipated that long-term settlement of the top of the waste surface will be

greater above the buried toe of the embankment where the waste soil will be thickest. Long-term

settlement may result in the waste surface becoming lower than the culvert inlets, resulting in areas of

standing water.

A riprap channel with ten check dams is located upstream of the culvert at Sta. 1006+500. The stream

channel and check dams will be founded on waste soil between 0 and 4 m thick. Long-term settlement

from the waste soil could result in settlement of various magnitudes along the stream channel. If long-

term settlement along the stream channel is undesirable, the waste soil below the stream channel should

be placed with a higher level of compaction.

The slope stability model at Sta. 1006+520 considers the effect of the B8 waste disposal area, see Section

7.3.7 and Figures 20 through 22. The LHS embankment fill slope is recommended based on the

assumption that waste soil will be placed up to 465 m elevation. If there is a possibility that waste soil will

not be placed up to 465 m elevation, or not placed in this area at all, then additional slope stability

modelling is required and a flatter LHS embankment fill slope will be recommended.

Geotechnical Recommendations by Station

Using the results of the geotechnical investigation and slope stability assessment, a summary of station-

specific preliminary recommendations are provided below.




Station Range Reference Geometric

Design

Configuration

Representative

Geotechnical

Investigation

Anticipated Subsurface Conditions Geotechnical Recommendations

From To

1004+330 1004+660

Cut up to 5 m

Fill up to 7 m

2H:1V to 4H:1V: Fill Slopes

TP18-LX-032

(Lynx West),

TP18-LX-033

(Lynx West),

TP18-LX-034,

TP18-LX-035,

TP18-LX-036,

TP18-LX-037,

TP18-LX-038,

CPT18-LX-007,

CPT18-LX-008.

Upper 0.1 to 0.2 m: Topsoil.

Below Topsoil Upper Terrace: Gravel, silty, sandy to 1.8 m depth, over

bedrock, or bedrock near surface

Below Topsoil Lower Terrace: 3.6 m to >5.0 m of clay. Test pits TP18-LX-035

and TP18-LX-036 encountered sand and silt (>1.2 m thick) below the clay.

Shale Bedrock: encountered in two test holes as follows:

- TP18-LX-032 (1.8 m – 473.1 m); and

- TP18-LX-033 (0.1 m – 470.1 m).

Groundwater: inferred at 6.2 m depth in CPT18-LX-008.

Stripping 0.2 m

Max Cut Slope 3H:1V (may encounter bedrock; bedrock slope can be cut steeper,

bedrock should be considered PAG)

Estimated Waste: 10%

Max Fill Slope LHS 3.00H:1.0V

Max Fill Slope RHS 3.10H:1.0V

Granular Fill

1004+660 1004+780

Scratch Grade

Shallow fills (<2 m) and

ditch cuts up to 1 m.

2H:1V Cut Slopes

2H:1V to 4H:1V Fill Slopes

TP18-LX-039.

Upper 0.1 m: Topsoil.

Below Topsoil: 2.3 m clayey sand with 0.3 m gravel with some clay below.

Below Gravel: >2.3 m of silt present.

Shale Bedrock: not encountered.

Groundwater: not encountered.

Stripping 0.1 m

Max Cut Slope 2H:1V


Max Fill Slope 3.00H:1V

Granular Fill

Non-woven geotextile separator likely required below SGSB.

1004+780 1004+840 Fill and Culvert Crossing

Fill up to ~4 m

TH18-LX-018,

TH18-LX-017,

TP18-LX-040,

TP18-LX-056,

CPT18-LX-009.

Upper 0.1 to 0.2 m: Topsoil

Below Topsoil: generally, sand and gravel interbedded with silt and clay over

shale bedrock.


- TH18-LX-018 (7.6 m – 459.4 m); and

- TH18-LX-017 (7.9 m – 459.7 m).


Stripping 0.2 m


Granular Fill

Hwy 29 alignment crosses an entrenched seasonal stream channel and located near

the distal edge of an alluvial fan. Indications of recent small debris flow/flood events

in channel (observed summer 2019). A 2.4 m diameter culvert with upstream check

dams is proposed.

Riprap along shoreline between Sta. 1004+580 and 1005+100 to provide long-term

reservoir shoreline erosion protection.

Non-woven geotextile separator likely required below SGSB, but not above fill around

the culvert.





Design

Configuration

Representative

Geotechnical

Investigation


From To

1004+840 1004+900

Scratch Grade

Shallow fills (<2 m) and

ditch cuts up to 1 m.

2H:1V Cut Slopes.

2H:1V to 4H:1V Fill Slopes.

TP18-LX-041.

Upper 0.1 m: Topsoil

Below Topsoil: 1.4 m sand and gravel over >3.4 m of silt.

Shale Bedrock: not encountered.


Stripping 0.1 m

Max Cut Slope 2H:1V



Granular Fill




1004+900 1005+460 Fill up to 9 m in height.

5H:1V Fill Slopes

TH19-LX-201,

TH19-LX-203,

TH18-LX-019,

TH18-LX-020,

TH18-LX-021,

TP18-LX-042,

TP18-LX-043,

CPT19-LX-202,

CPT19-LX-204,

CPT18-LX-010,

CPT18-LX-011,

CPT18-LX-012,

CPT18-LX-013.


Below Topsoil: a mixture of silt and clay, interbedded with sand and gravel

over shale bedrock.

Shale Bedrock: encountered in four test holes as follows:

- TH18-LX-019 (7.6 m – 458.3 m);

- TH19-LX-201 (5.5 m – 456.9 m);

- TH18-LX-020 (4.6 m – 454.5 m); and

- TH19-LX-203 (3.1 m – 457.7 m).

Groundwater: inferred at 2.4 m depth in CPT19-LX-202, and 2.7 m depth in

CPT19-LX-204.

Stripping 0.2 m

Max Fill Slope LHS 3.95H:1V

Max Fill Slope RHS 4.20H:1V

Granular Fill





1005+460 1005+500 Culvert Crossing

Fill up to ~3 m

TH19-LX-205,

TH19-LX-207,

CPT19-LX-206,

CPT18-LX-014.


Below Topsoil: a mixture of silt and clay over shale bedrock. Test hole TH19-

LX-207 encountered a gravel layer at 6.6 m to 7.3 m and a sand layer at 11.6

m to 12.5 m.


- TH19-LX-205 (7.0 m – 457.6 m); and

- TH19-LX-207 (13.7 m – 456.7 m).

Groundwater: encountered at 9.4 m in test hole TH19-LX-207, inferred at

6.1 m depth in CPT19-LX-206.

Stripping 0.2 m

Max Fill Slope 3.00H:1.0V

Granular Fill

Hwy 29 alignment crosses an entrenched stream channel and along distal edge of an

alluvial fan. Alignment is closer to alluvial fan than current highway crossing so risk

from debris flow/flood events higher than exists for the current highway crossing. A

2.0 m diameter culvert with upstream check dams is proposed.

Potential to encountered existing site disturbance (e.g. disturbed soil, fill, buried

debris) from previous land use. Sub-excavation may be required if site disturbance is

encountered during construction.







Design

Configuration

Representative

Geotechnical

Investigation


From To

1005+500 1005+690

Cut (up to 10m) left into

alluvial fan.

5H:1V Cut Slopes.

TH19-LX-208,

TH19-LX-209,

TH19-LX-210,

TH18-LX-022,

CPT19-LX-211,

CPT18-LX-015,

CPT18-LX-016,

CPT18-LX-017,

CPT18-LX-018,

CPT18-LX-019.

Upper 0.2 m: Topsoil.

Below Topsoil: a mixture of silt and clay, interbedded with sand and gravel

over shale bedrock.

Shale Bedrock: encountered in three test holes as follows:

- TH19-LX-208 (16.8 m – 457.2 m);

- TH19-LX-209 (18.7 m – 457.9 m); and

- TH19-LX-210 (12.3 m – 457.4 m).

Groundwater: encountered at 9.1 m in test hole TH19-LX-210, inferred at 6.1

m depth in CPT19-LX-211.

Stripping 0.2 m

Max Cut Slope 3.10H:1V



If seepage observed during construction a gravel blanket may be required on face of

slope.




1005+690 1005+910 Fill up to 13 m.

5H:1V Fill Slopes.

TH19-LX-212,

TH19-LX-213,

TH18-LX-023,

TH18-LX-024,

TH18-LX-025,

TP18-LX-044,

CPT19-LX-214,

CPT19-LX-215,

CPT18-LX-020,

CPT18-LX-021,

CPT18-LX-022,

CPT18-LX-023,

CPT18-LX-024.

Upper 0.1 m to 0.6 m: Topsoil

Below topsoil: 7.8 m to 13.7 m of clay. Test hole TH19-LX-213 encountered

sand at 13.7 m to 14.6 m.


- TH19-LX-212 (7.8 m – 456.1 m); and

- TH19-LX-213 (14.6 m – 453.0 m).

Groundwater: encountered at 3.7 m in test hole TP18-LX-044, inferred at 8.5


Stripping 0.6 m



Granular Fill

RHS, potential to encounter existing site disturbance (e.g. buried foundations,

disturbed soil, fill) from previous land use. Sub-excavation may be required if site

disturbance is encountered during construction. Gas bubbles observed in pond near

Sta. 1005+880.









Design

Configuration

Representative

Geotechnical

Investigation


From To

1005+910 1005+970

Cut left up to 7 m into

alluvial fan.

Cut slope 2H:1V.

TH19-LX-216,

TH19-LX-217,

TH19-LX-218,

TH18-LX-026,

TPH18-LX-045.


Below topsoil: a mixture of silt and clay, interbedded with sand over

bedrock.

Shale Bedrock: encountered in all test holes as follow:

- TH19-LX-218 (12.8 m – Elev. 451.0 m);

- TH19-LX-217 (13.9 m – Elev. 455.2 m); and

- TH19-LX-216 (23.3 m – Elev. 457.7 m).


Stripping 0.6 m

Max Cut Slope 2.5H:1.0V (with angular rock shear key)

Estimated Waste 100%.


Granular Fill




1005+970 1006+120 Fill up to 15 m.

2H:1V to 4H:1V Fill Slopes.

TH18-LX-027,

TH18-LX-028,

TH18-LX-029,

PV18-LX-033,

TPH18-LX-046,

TPH18-LX-047,

CPT19-LX-219.


Below topsoil: In test holes TPH18-LX-046 and TH18-LX-027 clay was

encountered (2.3 m to 3.1 m thick). Test hole TH18-LX-029 encountered

gravel (1.8 m thick) below the topsoil.

Shale Bedrock: encountered in three test holes as follows:

- TPH18-LX-046 (2.4 m – Elev. 455.5 m);

- TH18-LX-029 (2.6 m – Elev. 443.8 m); and

- TH18-LX-027 (3.8 m – Elev. 453.3 m).

Groundwater: encountered at 1.5 m in test hole TH18-LX-029, inferred at 5.6


Stripping 0.8 m



Granular Fill



Soil waste disposal site B8 on LHS.





Design

Configuration

Representative

Geotechnical

Investigation


From To

1006+120 1006+210

Fill up to 15 m over existing

highway 29.

Left Slope - 2H:1V to 4H:1V

Right Slope – 3H:1V

TH19-LX-220,

TPH18-LX-049,

CPT19-LX-221.


Below topsoil: 2.5 m to 8.5 m of clay over 0.6 m of sand and gravel.

Shale Bedrock: encountered in TH19-LX-220 at 9.5 m (Elev. 453.4 m).


Stripping 0.6 m



Granular Fill

Soil waste disposal site B8 on LHS.

1006+210 1006+780

Fill up to 25 m on right side

of highway.

Fill up to 15 m on left side

of highway

Left Slope - 2H:1V to 4H:1V


Part of Early Works

Left of Highway

TH19-LX-224,

TH19-LX-225,

TH19-LX-228,

TH18-LX-033,

CPT19-LX-222,

CPT19-LX-223,

CPT19-LX-227.


Below topsoil: 3.6 m to 12.8 clay over bedrock. Test hole TH19-LX-224

encountered sand below the clay. Test hole TH18-LX-033 encountered 1.5 m

of silty sand at ground surface.

Shale Bedrock: encountered in all test holes at depths ranging from 3.8 m

to 15.2 m.

Bedrock depths were as follows:

- TH19-LX-224 (15.2 m – Elev. 450.4 m);

- TH19-LX-225 (13.1 m – Elev. 451.4 m);

- TH18-LX-033 (11.6 m – Elev. 446.5 m); and

- TH19-LX-228 (3.8 m – Elev. 449.4 m).


Stripping RHS 0.1 m (If organic soil or organic debris is identified during construction

review, sub-excavation of organic soil or organic debris will be required).

Stripping LHS 0.3 m

Max Fill Slope LHS 2.0H:1.0V (LHS fill slope assumes fill (waste) placed against toe of

slope up to 465 m elevation. Soil waste disposal site B9).

Max Fill Slope RHS to be confirmed after in-river platform built and additional

investigation carried out

Granular Fill

Existing slide (not remediated) between Sta. 1006+380 and 1006+460 on RHS slope.

Potential sub-excavation for settlement objectives; however, sub-excavation not

required for stability objective.

Left of Hwy 29 alignment there are three separate but coalesced/overlapping alluvial

fans. The alignment is shifted away from the fans and is higher than the current

highway. Qualitatively, the risk from debris flow/flood events appears to be less for

the alignment that the existing highway. Three culverts are proposed, one culvert is

2.7 m in diameter with 10 upstream check dams.

Under Existing

Highway 29

TH19-LX-226,

TH18-LX-037,

PV18-LX-034.

Upper 0.1 m: Asphalt pavement.

Below Asphalt: 1.3 m to 1.5 m gravel fill.

Below Fill: Generally, silt and clay, with a gravel layer at 8.3 m to 12.4 m in

TH19-LX-226, and a sand layer at 10.5 m to 13.4 m in TH18-LX-037.

Shale Bedrock: was encountered in two test holes as follows:

- TH19-LX-226 (12.4 m – Elev. 445.4 m); and

- TH18-LX-037 (13.4 m – Elev. 444.8 m).


Existing fill below highway is anticipated to be variable in composition and

density.

Slope to the

Right of Existing

Highway 29

TH18-LX-030,

TH18-LX-034,

TPH18-LX-050.


Below Topsoil: 0.6 m to 3.8 m of silt and clay.

Below Silt and Clay: 0.9 m to 4.7 m of sand and gravel, with varying silt

content over shale bedrock.

Shale Bedrock: was encountered in three test holes as follows:

- TH18-LX-030 (4.0 m – Elev. 452.0 m);

- TH18-LX-034 (8.5 m – Elev. 444.2 m); and

- TPH18-LX-050 (2.0 m – Elev. 443.7 m).

Groundwater: encountered at 0.6 m in test hole TPH18-LX-050.

Slide between 1006+380 and 1006+460 (not remediated).

Fill may have been side cast over the RHS.





Design

Configuration

Representative

Geotechnical

Investigation


From To

Near Peace River

TH18-LX-031,

TPH18-LX-048,

TH18-LX-035,

TH18-LX-038.


Below Topsoil: 1.1 m to 2.3 m of sand and gravel, with varying silt content

over shale bedrock.

Shale Bedrock: encountered in all test holes at depths ranging from 1.1 m

to 2.6 m.

Bedrock depths were as follows:

- TH18-LX-031 (1.1 m – Elev. 445.1 m);

- TPH18-LX-048 (2.6 m – Elev. 444.3 m);

- TH18-LX-035 (2.3 m – Elev. 443.5 m); and

- TH18-LX-038 (1.3 m – Elev. 445.5 m).

Groundwater: encountered in all test holes at depths ranging between 0.6 m

and 0.8 m.

1006+780 1006+860

Fill up to 8 m on left side of

highway.

Fill up to 25 m on right side

of highway.

Left Slope – 2H:1V to 4H:1V


Part of Early Works

Under existing

Highway 29

TH18-LX-039.


Below Asphalt: 2.1 m gravel fill.

Below Fill: 2.0 m of gravel over silt and clay.

Shale Bedrock: encountered at 13 m (Elev. 448.0 m) in test hole TH18-LX-

039.

Groundwater not encountered.


density.

Stripping 0.3 m (If organic soil or organic debris is identified during construction


Max Fill Slope LHS 2.0H:1.0V (LHS fill slope assumes fill (waste) placed against toe of

slope up to 465 m elevation. Soil waste disposal site B9). Max Fill Slope RHS to be

confirmed after in-river platform built and additional investigation carried out.

Granular Fill

Existing slide (historically remediated) between Sta. 1006+780 and 1006+900 on RHS

slope. Potential sub-excavation for settlement objectives; however, sub-excavation

not required for stability objective.

Slope to the

Right of Existing

Highway 29

TH18-LX-101,

TH18-LX-102.


Below Topsoil: generally sand and gravel interbedded with silt and clay over

bedrock.


- TH18-LX-101 (9.8 m – Elev. 444.6 m); and

- TH18-LX-102 (8.5 m – Elev. 444.6 m).



Fill above Peace

River

TH18-LX-103

Upper 6.2 m: gravel over shale bedrock.

Shale Bedrock: was encountered at 6.2 m (Elev. 444.4) in test hole TH18-LX-

103.






Design

Configuration

Representative

Geotechnical

Investigation


From To

1006+860 1007+030

Fill on right side of highway.

Left Slope – 2H:1V to 4H:1V


Part of Early Works

Under existing

Highway 29

TH18-LX-041,

TH18-LX-105.


Below Asphalt: 1.1 m to 1.4 m sand and gravel fill.

Below Fill: generally, silt and clay interbedded with sand and gravel over

bedrock.


- TH18-LX-041 (12.8 m – Elev. 452.5 m); and

- TH18-LX-105 (9.9 m – Elev. 458.1 m).



density.




Max Fill Slope RHS fill slope to be confirmed after in-river platform built and

additional investigation carried out.

Granular Fill

Existing slide (historically remediated) between Sta. 1006+780 and 1006+900 on RHS

slope. Potential sub-excavation for settlement objectives; however, sub-excavation

not required for stability objective.

Existing slide (not remediated and recently active) between Sta. 1006+900 and

1007+030 on RHS slope. Potential sub-excavation for settlement objectives; however,

sub-excavation not required for stability objective.

Slope to the

Right of Existing

Highway 29

TH18-LX-104.


Below Topsoil: 5.8 m of clay over 0.9 m of gravel.

Shale Bedrock: was encountered at 6.7 m (Elev. 445.5 m) in test hole TH18-

LX-104.



Existing slide (historically remediated) between Sta. 1006+780 and

1006+900

Existing slide (not remediated and recently active) between Sta. 1006+900

and 1007+030

Near Peace River

TH18-LX-042.

Upper 0.2 m: clay.

Below Clay: 1.4 of gravel over shale bedrock.


LX-042.


1007+030 1007+070

Culvert crossing and debris

fan. Large Fill up to 28 m

into the river.

3H1:1V Fill Slopes.

Part of Early Works

Under existing

Highway 29

TH18-LX-044.


Below Asphalt: 10.7 m sand and gravel fill.

Below fill: 7.6 m of silty sand and, sand and gravel over shale bedrock.


LX-044.



density.






Granular Fill

Highway 29 alignment crosses a well-known debris flow and flood area near Sta.

1007+060. Events that plug/damage existing culvert and/or overtop current highway

occur approximately every 5 years. A 2.4 m diameter culvert with upstream check

dams is proposed.

Fill above Peace

River

TP19-LX-229,

TPH18-LX-052.

Upper 5.2 m: gravel and sand over shale bedrock.

Shale Bedrock: was encountered at 5.2 m (Elev. 441.1 m) in test hole TPH18-

LX-052.


Fill may have been side cast over the RHS. Variable colluvium deposit from

various debris flow events.





Design

Configuration

Representative

Geotechnical

Investigation


From To

1007+070 1007+280

Large Fill up to 28 m into

the river, transitions to

reservoir shoreline

protection berm.

3H1:1V Fill Slopes.

Part of Early Works

TH18-LX-045

Upper 0.1 m: sand fill.

Below Fill: silty sand interbedded with clay over shale bedrock.


LX-045.







Granular Fill



Project # KX052807.11 | 20 May 2020 Page 48

References

AMEC Environment & Infrastructure (05 March 2012). Report. Preliminary Geotechnical Assessment,

Proposed Lynx Creek Segment, Highway 29 Definition Design, Site C Clean Energy Project.

Submitted to R.F. Binnie & Associates Ltd.

BCMoTI (2016) 2016 Standard Specifications for Highway Construction. Adopted July 1, 2016

BGC Engineering Inc. (30 November 2012). Report. Site C Clean Energy Project, Preliminary Reservoir

Impact Lines. Submitted to BC Hydro.

Bidwell, A.K. (May 1999).The Engineering Geology of the Fort St. John Area. Master of Engineering Report,

University of Alberta.

Binnie & Associates Ltd. (June 2020). Highway No. 29, Lynx Creek, Suggested Construction Staging,

Drawings R3-336-1200 to -1206.

Bowles, J.E. (1996). Foundation Analysis and Design, Fifth Edition. McGraw-Hill International Editions

GEO-SLOPE International Ltd., Computer Program, GeoStudio 2016, version 8.16.5.15361.

Hartman, G.M.D. and Clague, J.J. (25 June 2008). Quaternary Stratigraphy and Glacial History of the Peace

River Valley, Northeast British Columbia. Canadian Journal of Earth Science, Volume 45, pages

549-564.

Lunne, T., Robertson, P.K., Powell, J.J.M (1997) Cone Penetration Testing in Geotechnical Practice. Spon

Press.

Stott, D.F. (1982). Lower Cretaceous Fort St. John Group and Upper Cretaceous Dunvegan Formation of the

Foothills and Plains of Alberta, British Columbia, District of Mackenzie and Yukon Territory.

Geological Survey of Canada, Bulletin 328.

Stark, T.D., Eid, H.T. (1994). Drained Residual Strength of Cohesive Soils. Journal of Geotechnical

Engineering, Vol. 120, No. 5.

Wood Environment & Infrastructure Solutions (04 November 2019a). Memorandum. Highway 29 – Lynx

Creek East – Relative Debris Flow Risk. Submitted to R.F. Binnie & Associates Ltd.

Wood Environment & Infrastructure Solutions (06 November 2019b). Memorandum. Highway No. 29, Lynx

Creek East, Preliminary Stability Assessment of Farrell Creek Road Slide and In-Stream Reservoir

Shoreline Stability Berm. Submitted to R.F. Binnie & Associates Ltd.

Wood Environment & Infrastructure Solutions (6 November 2019c). Geotechnical Data Report, Lynx Creek

East Segment. Submitted to R.F. Binnie & Associates Ltd.

Wood Environment & Infrastructure Solutions (16 March 2020). Geotechnical Data Report, Lynx Creek West

Segment. Submitted to R.F. Binnie & Associates Ltd.

Appendix A

Figures 1 to 4

Geotechnical Investigation

Figure 5

Shear Key Sta. 1005+940

L1000-LINEDesign

Alignment

Hwy 29

P e a c eR i v e r

L y n x

C r e e k

D r yC r e e k

F a r r e l l

Cre

ek

LynxCreekWest

LynxCreekEast

Notes:1. L1000-LINE centreline alignment provided by R.F. Binnie & Associates Ltd. CAD file '20200417 - Lynx Creek 100DD - UTM.dwg', received 17 April 2020.2. Image provided by Bing Maps Road - © 2019 Microsoft Corporation © 2018 HERE

LegendL1000-LINE Centreline Alignment

Borrow Investigation Area

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S:\Internal\KX052807-GIS\1-LynxCreek\LCE-AlignGeotechInv-DetDes-Fig1-SiteLocPlan.mxd

SCALE:

PROJECTION:

DATUM:

CHK'D BY:

DWN BY: TITLE:

PROJECT:REV NO.:

PROJECT NO.:

DATE:

HIGHWAY NO. 29LYNX CREEK EASTUTM Zone 10

NAD 83

EM

BB SITE LOCATION PLANGEOTECHNICAL INVESTIGATION

A

FIGURE 1

KX052807.11

JUNE 2020

$

1:150,000

0 2 4 6 81km

3456 Opie CrescentPrince George, BC, CANADA V2N 2P9Tel. (250) 564-3243 Fax (250) 562-7045

WoodEnvironment & Infrastructure Solutions

a Division of Wood Canada Limited (Wood)

BC HYDRO c/o R.F. BINNIE &ASSOCIATES LTD.


a Division of Wood Canada Limited (Wood)Wood Environment & Infrastructure Solutions

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Highway 29

P e a c eR i v e r

TH19-LX-201TH19-LX-203

TH19-LX-205

TH19-LX-207 TH19-LX-208

TH19-LX-209

TH19-LX-210TH19-LX-212

TH19-LX-213TH19-LX-216

TH19-LX-217

TH19-LX-218

TH19-LX-220CPT19-LX-202

CPT19-LX-204CPT19-LX-206 CPT19-LX-211

CPT19-LX-214

CPT19-LX-215

CPT19-LX-219

CPT19-LX-221

CPT19-LX-222

CPT19-LX-223

TH19-LX-224 TH19-LX-225

TH19-LX-226

TH19-LX-228CPT19-LX-227

TH18-LX-017

TH18-LX-018

TH18-LX-019TH18-LX-020

TH18-LX-021

TH18-LX-022

TH18-LX-023 TH18-LX-024

TH18-LX-025

TH18-LX-026

TH18-LX-027

TH18-LX-028TH18-LX-029

TPH18-LX-045

TPH18-LX-046

TPH18-LX-047

TPH18-LX-049

CPT18-LX-018CPT18-LX-007CPT18-LX-008

CPT18-LX-009

CPT18-LX-010

CPT18-LX-011CPT18-LX-012

CPT18-LX-013

CPT18-LX-014

CPT18-LX-015

CPT18-LX-016

CPT18-LX-017

CPT18-LX-019

CPT18-LX-020CPT18-LX-021 CPT18-LX-022

CPT18-LX-023CPT18-LX-024

TP18-LX-056TP18-LX-034

TP18-LX-035

TP18-LX-036

TP18-LX-037

TP18-LX-038TP18-LX-039

TP18-LX-040

TP18-LX-041 TP18-LX-042

TP18-LX-043

TP18-LX-044

PV18-LX-025

PV18-LX-026

PV18-LX-027

PV18-LX-028

PV18-LX-029

PV18-LX-030 PV18-LX-031

PV18-LX-032

PV18-LX-033

PV18-LX-034 TH18-LX-030TH18-LX-031

TH18-LX-033

TH18-LX-034

TH18-LX-035 TH18-LX-038TPH18-LX-048TPH18-LX-050

PV18-LX-035 PV18-LX-036

TH81-18

PDH78-1

TH81-17

TP18-LX-032

TP18-LX-033

PROJECTION:

DATUM:

CHK'D BY:

DWN BY:


CLIENT: DATE:

KX052807.11

JUNE 2020

A

SITE PLAN WITH ORTHOPHOTOGEOTECHNICAL INVESTIGATION

HIGHWAY NO. 29LYNX CREEK EAST FIGURE 2

TITLE:

PROJECT:

UTM Zone 10

NAD 83

EM

BBPROJECT NO.:

REV NO.:

1 of 2SHEET NO.1:5,000S:\Internal\KX052807-GIS\1-LynxCreek\LCE-AlignGeotechInv-DetDes-Fig2-SitePlan-Ortho.mxd

MAIN VIEW SCALE:

0 100 200 300 40050m

Notes:1. L1000-LINE centreline alignment, slope stake lines, disposal sites, approximate extent of early works and supporting linework provided by R.F. Binnie & Associates Ltd. CAD file '20200417 - Lynx Creek 100DD - UTM.dwg', received 17 April 2020.2. Maximum Normal Reservoir Level (461.8 m) downloaded from BC Hydro SharePoint 11 April 2018.3. Orthophoto imagery (foreground) provided by BC Hydro 9 January 2018.4. Orthophoto imagery (background; 2009) provided by R.F. Binnie & Associates Ltd., received 1 June 2011.

BC HYDRO c/o R.F. BINNIE & ASSOCIATES LTD.Legend

!A 2019 Alignment Test Hole Location

") 2019 Alignment Test Pit Location

#* 2019 Alignment CPT Location

!A 2018 Alignment Test Hole Location") 2018 Alignment Test Pit Location#* 2018 CPT Location

") 2018 Pavement Core Location!A Historical Drillhole Location

Maximum Normal Reservoir Level(461.8 m)

L1000-LINE Centreline AlignmentL2-LINE Centreline AlignmentSlope Stake LineCulvertDisposal SiteApproximate Extent of Early Works

$

21

1:75,000


a Division of Wood Canada Limited (Wood)Wood Environment & Infrastructure Solutions

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NSTR

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Highway 29P e a c e R i v e r

TH19-LX-212

TH19-LX-213TH19-LX-216

TH19-LX-217

TH19-LX-218

TH19-LX-220

CPT19-LX-214

CPT19-LX-215

CPT19-LX-219

CPT19-LX-221

CPT19-LX-222

CPT19-LX-223

TH19-LX-224 TH19-LX-225

TH19-LX-226

TH19-LX-228

TP19-LX-229

CPT19-LX-227

TH18-LX-024

TH18-LX-025

TH18-LX-026

TH18-LX-027

TH18-LX-028TH18-LX-029

TPH18-LX-045

TPH18-LX-046

TPH18-LX-047

TPH18-LX-049CPT18-LX-023

CPT18-LX-024TP18-LX-044

PV18-LX-033

PV18-LX-034 TH18-LX-030TH18-LX-031

TH18-LX-033

TH18-LX-034

TH18-LX-035

TH18-LX-037

TH18-LX-038

TH18-LX-039 TH18-LX-041

TH18-LX-042TH18-LX-044

TH18-LX-045

TH18-LX-101TH18-LX-102

TH18-LX-103 TH18-LX-104 TH18-LX-105TPH18-LX-048TPH18-LX-050

TPH18-LX-052

PV18-LX-035 PV18-LX-036

TH81-18

PDH78-1

TP05-02

BH06-01BH06-02

PV05-01

TH96-01

TH96-02TP96-01

TP96-03

TH81-17

TH80-02

TH79-1

TH79-2DH11-41

PROJECTION:

DATUM:

CHK'D BY:

DWN BY:


CLIENT: DATE:

KX052807.11

JUNE 2020

A

SITE PLAN WITH ORTHOPHOTOGEOTECHNICAL INVESTIGATION

HIGHWAY NO. 29LYNX CREEK EAST FIGURE 2

TITLE:

PROJECT:

UTM Zone 10

NAD 83

EM

BBPROJECT NO.:

REV NO.:

2 of 2SHEET NO.1:5,000S:\Internal\KX052807-GIS\1-LynxCreek\LCE-AlignGeotechInv-DetDes-Fig2-SitePlan-Ortho.mxd

MAIN VIEW SCALE:

0 100 200 300 40050m

Notes:1. L1000-LINE centreline alignment, slope stake lines, disposal sites, approximate extent of early works and supporting linework provided by R.F. Binnie & Associates Ltd. CAD file '20200417 - Lynx Creek 100DD - UTM.dwg', received 17 April 2020.2. Maximum Normal Reservoir Level (461.8 m) downloaded from BC Hydro SharePoint 11 April 2018.3. Orthophoto imagery (foreground) provided by BC Hydro 9 January 2018.4. Orthophoto imagery (background; 2009) provided by R.F. Binnie & Associates Ltd., received 1 June 2011.

BC HYDRO c/o R.F. BINNIE & ASSOCIATES LTD.Legend

!A 2019 Alignment Test Hole Location

") 2019 Alignment Test Pit Location

#* 2019 Alignment CPT Location

!A 2018 Alignment Test Hole Location") 2018 Alignment Test Pit Location#* 2018 CPT Location

") 2018 Pavement Core Location!A Historical Drillhole Location

Maximum Normal Reservoir Level(461.8 m)

L1000-LINE Centreline AlignmentL2-LINE Centreline AlignmentSlope Stake LineCulvertDisposal SiteApproximate Extent of Early Works

$

21

1:75,000

1004+300

470 470

Elevation (m

)

Station (m)

Elevation (m

)

460 460

1004+400 1004+500 1004+600 1004+700 1004+800 1004+900

480 480

490 490

ST

A 1004+

330.000

61.5

m -

900

mm

Ø C

SP

2.0

WT

@ 1

.37%

25.0

m -

240

0mm

Ø C

SP

3.5

WT

@ 3

.33%

LYNX

CREEK

WEST

LYNX

CREEK

EAST

TS

GP-GCML

END

0.1

2.42.7

5

m

TP18-LX-039TS

ML

END

0.11.5

4.9

914

23

18

m

TP18-LX-041WW

SC3

GM2

9177

28

18

21

26

40

WW PL LL

2000010000 250125

qt(kPa) fs

(kPa)

CPT18-LX-009

Refusal

5

TS

CL

END

0.2

4.45

28

3130

3124

m

TP18-LX-034WW

TS

CL

ENDWater Level6/23/2018

0.2

3.85

28

32

3024

24

22 44

m

TP18-LX-035WW PL LL TS

CL

CHENDWater Level

6/24/2018

0.2

4.25

26

31

32

3030

23

22

22

39

45

51

m

TP18-LX-036WW PL LL

TS

CL

END

0.1

5.2

22

29

30

2928

22

20

23

40

34

47

m

TP18-LX-037WW PL LL

TS

CL

END

0.1

5

151714242323292529

21

21

21

33

41

34

m

TP18-LX-038WW PL LL

SM4 SM4

MH

SPBR

2.33.1

6.1

7.67.99.2

448

13447

7

65

R

1214137

292930

23

87

12

m

TH18-LX-017N WW

SM4

GM2

SM3

END

BR0.1

1.82 END

84

m

TP18-LX-032WW

GM3

TS

N/A

PROJECTION:

N/A

DATUM:

PROFILE – L1000-LINE ALIGNMENT

STATION 1004+300 TO 104+950

GEOTECHNICAL INVESTIGATION

PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

AS NOTED

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 3

SHEET NO. 1 of 5

Notes:

1. Hole elevation taken from LIDAR provided by BC Hydro 9 January 2018.

2. SPT N values and associated laboratory testing data provided with the Sticklogs may not be presented

at representative elevations. Please refer to Appendix B – Investigation Logs for additional details.

3. L1000-LINE centreline alignment profile and existing ground profile at centreline provided by R.F. Binnie

& Associates Ltd. CAD file '20200608 ACAD-200PR_LYNX.dwg', received 8 June 2020.

Wood Environment & Infrastructure Solutions



BC HYDRO c/o R.F. BINNIE & ASSOCIATES LTD.

0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Legend

L1000-LINE Centreline Alignment Profile

Existing Ground Profile at Centreline

Maximum Normal Reservoir Level (461.8 m)

470

Elevation (m

)

Station (m)

460

1005+000 1005+100 1005+200 1005+300

480

470

Elevation (m

)

460

1005+400 1005+500 1005+600

450

480

450

42.5m

- 1200m

m Ø

C

SP

2.8 W

T @

2.65%

60.5

m -

120

0mm

Ø C

SP

2.8

WT

@ 0

.80% 35

.0m

- 2

000m

m Ø

CS

P2.

8 W

T @

4.7

7%

MNRL

Cross Section

Station 1005+340

See Figure 4 Sheet 1

qt(kPa) fs

(kPa)

CPT18-LX-010

Refusal

5

qt(kPa) fs

(kPa)

CPT18-LX-011

Refusal

5

qt(kPa) fs

(kPa)

CPT18-LX-012

Refusal

2

4

2000010000 250125

2000010000 250125

2000010000 250125CL

ML

0.2

5.36.17.6

10.6END

6558

12182311

R

442530282635282723

10

1921

3041

0.83 / 3.03

0.54 / 1.6

m

TH18-LX-019N WW PL LL Is50

Dia/Axial

qt(kPa) fs

(kPa)

CPT19-LX-206

Refusal

5

2000010000 250125

(MPa)

BR

SM2

TS

TS

CL

BR

0.2

3.84.65.56.7 END

1043123622R

R

303730293232199

229

10

2424

26

4040

50

m

TH19-LX-201N WW PL LL

TS

CL

BR

0.1

3.14.3 END

46556RR

26212526253011

24

2629

45

4955

m


TS

CL

BR

0.6

16.817.8 END

334875

6

7

7

7

9

5

6

R

R

2114141615

23

1827

17

21

25

30

23

20

17

18

30

33

27

m


SM3SM2

N/A

PROJECTION:

N/A

DATUM:


STATION 104+950 TO 105+600


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

AS NOTED

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 3

SHEET NO. 2 of 5





0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Legend




Notes:






470

Elevation (m

)

460

1005+600 1005+700 1005+800 1005+900 1006+000

450

480

470

Station (m)

Elevation (m

)

460

1006+000 1006+100 1006+200

450

480

40.5

m -

160

0mm

Ø C

SP

2.8

WT

@ 2

.00%

44.5

m -

120

0mm

Ø C

SP

2.8

WT

@ 1

.51%

Cross Section

Station 1005+660


Cross Section

Station 1005+840


MNRL

Cross Section

Station 1005+940


TSML

CL

BR

0.21.42.1

12.313.2

Water Level4/29/2019

461161078

8

5

6

5

RR

30

7119715

12

27

30

32

211917

16

18

26

33

m


TS

CL

BR

0.6

7.88.6

534111087

8

RR

1822181013122522

26

2621

16

17

17

28

32

31

m


TS

CL

SM4

CL

BR

0.6

4.9

6.7

13.914.9

5812

71814

32

14

12

12

4

R

R

232421

23182114

13

25

17

9

20

25

18

15

15

33

29

18

m


Refusal

qt(kPa) fs

(kPa)

CPT19-LX-214

5

10

2000010000 250125

qt(kPa) fs

(kPa)

CPT19-LX-219

Refusal

5

qt(kPa) fs

(kPa)

CPT19-LX-221

Refusal

5

qt(kPa) fs

(kPa)

CPT19-LX-223

Refusal

5

2000010000 250125

2000010000 250125

2000010000 250125

SM2

ENDEND

END

N/A

PROJECTION:

N/A

DATUM:


STATION 1005+600 TO 1006+250


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

AS NOTED

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 3

SHEET NO. 3 of 5





0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Legend




Notes:






470

Elevation (m

)

Station (m)

460

1006+300 1006+400 1006+500 1006+600

450

440

430

470

Elevation (m

)

460

1006+700 1006+800 1006+900

450

430

440

41.5

m -

120

0mm

ØC

SP

2.8

WT

@2.

53%

39.0

m -

900

mm

Ø C

SP

2.0

WT

@ 2

.00%

35.0

m -

900m

m Ø

CS

P 2

.0W

T @

2.00

%

30.0

m -

270

0mm

Ø C

SP

3.5

WT

@ 2

.00%

Highway 29

MNRL

Cross Section

Station 1006+420


Cross Section

Station 1006+900


ASPHGP-GM

CH

CL

GP-GC

0.11.6

8.3

18.5 END

2057105128

11

15

3

26292227272728182214

24

17

55

42

N/A / N/A

N/A / N/A

N/A / N/A

1.01 / 2.74

0.87 / 2.83

1.98 / 2.07

5.61 / 4.43

m

TH19-LX-226N WW PL LL Is50Is50

Dia/AxialTS

CH

SP

BR

0.1

3.14

19.7 END

56831535R

2016202119245

m

TH18-LX-030N WW

CLCHML

BR

1.22.3

3.8

7.28.5

21.1 END

816171764613

14

R

232026301826302012

28914

25

22

49

55

m


SM1

GM1TS

BR

0.61.3

12.4END


m

TH18-LX-038

TS

CL

ML

BR

00.62.3

8.59.8

19.9

7796

16

7

16

2239

57RR

89

121714

14

17

1069

17 28

m


GP-GM

BR

3.8

6.2

10.8 END

1431

23RR121316

R

433

71210

15

m

TH18-LX-103

N WW

GM2

SM4

GM2GM2

END

VWP

(4/3/2019)

VWP

(4/3/2019)

1.14 / 2.420.66 / 2.77

4.97 / 5.11

5.15 / 5.24

4.55 / 4.14

5.14 / 6.60

0.67 / 2.19

0.15 / 3.74

1.35 / 2.04

1.92 / 3.72

Is50Is50Dia/Axial

(MPa)

0.10 / 2.28

4.76 / 3.87

1.47 / 3.89

4.19 / 5.85

4.58 / 4.09

5.85 / 5.05

5.92 / 4.73

1.09 / 1.09

Is50Dia/Axial

(MPa)

(MPa)

6.7

189R

92RR

91399

2.68 / 5.133.81 / 5.54

1.67 / 5.18

0.51 / 2.95

0.16 / 1.06

4.41 / 5.62

8.57 / 6.67

N WW Is50Is50Dia/Axial

(MPa)

4.26 / 2.834.83 / 6.80

3.85 / 3.88

2.43 / 4.20

1.67 / 3.43

1.56 / 5.05

2.54 / 2.01

Is50Is50Dia/Axial

(MPa)

0.93 / 5.61

2.10 / 6.92

6.88 / 6.58

Is50Is50Dia/Axial

(MPa)

12.4

BR

N/A

PROJECTION:

N/A

DATUM:


STATION 1006+250 TO 1006+900


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

AS NOTED

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 3

SHEET NO. 4 of 5





0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Legend




Notes:




3. Not all instrumentation, groundwater levels, and slope inclinometer movement levels shown.



470

480

Elevation (m

)

Station (m)

460

1006+900 1007+000 1007+100 1007+200 1007+300

450

440

430

490

470

480

Elevation (m

)

460

450

430

490

1007+400 1007+500

500

440

500

30.0

m -

240

0mm

Ø C

SP

3.5

WT

@ 4

.00%

35.0

m -

900m

m Ø

CS

P 2

.0W

T @

2.00

%

LIM

IT O

F C

ON

ST

RU

CT

ION

ST

A 1

007+

280.

000

Cross Section

Station 1006+900


Highway 29

13

ASPHGP

CL

CL

BR

0.10.81.2

5.8

8.8

11.912.8

26.2 END

73634

1010

11

8

14

48R

R

31612211718

2214

15

19

14

15

15

19

38

37

28

m


ASPH

BR

0.1

3.8

7.6

10.7

15.8

18.3

24.4 END

24714979261312

10

11

R

12

14

16

15

37

R

R

225471211

6

9

11

12

12

12

13

14

8

7

m

TH18-LX-044N WW

1189

161821

19

15

7211311

m

TH18-LX-105N WW

FILLSP-SM

ML

ML

BR

0.11.52.3

5.6

9.9

30.9 END

536378656

9

20

213

GC4

SM4

GM1

SM2

GM1

SM4

SM2

SM2FILL

ASPH

N/A / N/A0.26 / 1.07

0.82 / 3.46N/A / N/A

3.84 / 5.39

3.36 / 5.99

5.48 / 3.80

1.81 / 3.88

3.28 / 5.29

6.67 / 6.45

Is50Dia/Axial

(MPa)

0.68 / 1.08

N/A / N/A

3.24 / 4.59

3.78 / 3.63

1.91 / 3.69

1.83 / 2.84

1.58 / 2.24

4.76 / 5.82

1.71 / 4.66

7.52 / 5.45

2.68 / 3.13

2.23 / 6.13

1.70 / 2.75

Is50Dia/Axial

(MPa)

2.48 / 4.68

2.47 / 3.66

1.17 / 3.74

Is50Is50Dia/Axial

(MPa)

N/A

PROJECTION:

N/A

DATUM:


STATION 1006+900 TO 1007+550


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

AS NOTED

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 3

SHEET NO. 5 of 5





0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Legend



Notes:






4. Additional existing ground surface provided by R.F. Binnie & Associates Ltd. CAD file

'EXSURF-COG-17-0472.dwg', received 30 October 2019.

Maximum Normal Reservoir Level

(461.8 m)

-40 -20 0 20 40

Elevation (m

)

480

Offset (m)

460

60

440

Elevation (m

)

480

440

80

460

MNRL

℄L1000-LINE

TSCLBR

0.1

3.14.3 END

46556RR

26212526253011

242629

454955

m


qt(kPa)

R

fs(kPa)20000

CPT19-LX-204

10000 1000500

R

CPT19-LX-202

qt(kPa) fs

(kPa)1000

20000

2

50010000

24

4 R

qt(kPa)

CPT18-LX-013

fs(kPa)

2

25020000

10000 500

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

1005+340


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

1:600

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 4

SHEET NO. 1 of 6





Notes:



2. Typical cross section based on L1000-LINE centreline alignment and existing ground surface provided

by R.F. Binnie & Associates Ltd. CAD file 'ACAD-R3-336-L1000-1004+330 to 1006+000.dwg', received

3 June 2020.

Legend

Typical Cross Section Based on L1000-LINE Centreline Alignment

Existing Ground Surface


24181260m

1 : 600

-40 -20 0 20

Elevation (m

)

480

Offset (m)

460

440

Elevation (m

)

480

460

440

-60

℄L1000-LINE

TS

CL

GP-GM

CL

BR

0.6

3.84.5

18.719.9 END

45

2269

257

5

7

7

10

16

10

15

35141611203

13

15

20

26

23

20

20

19171613

17

18

28

41

m


TS ML

CL

BR

0.21.42.1

12.313.2


46

116

107885

6

5RR

30

71197

1512

27

30

32211917

16

18

26

33

m


R

qt(kPa) fs

(kPa)

CPT19-LX-211

5

10

2000010000 1000500SM2

END

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

1005+660


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

1:600

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 4

SHEET NO. 2 of 6





Notes:





3 June 2020.

Legend




24181260m

1 : 600

-20 0 20 40

Elevation (m

)

480

Offset (m)

460

60

440

Elevation (m

)

480

460

440

-40 80

℄L1000-LINE

MNRL

TS

CL

SP-SMBR

0.6

13.714.616.3

73028111517222212

4

4

8

6RR

22131112131691012

19

19

18

16

19

15

14

13

42

24

20

23

m


R

qt(kPa) fs

(kPa)

CPT19-LX-214

5

20000

10

10000 250125

R

qt(kPa) fs

(kPa)

CPT18-LX-023

2000010000 500250

2

4

TS

CL0.1

4 END Water Level6/7/2018

1717

1020

16

2014

13

3526

m

25

TP18-LX-044WW PL LL

END

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

1005+840


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

1:600

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 4

SHEET NO. 3 of 6





Notes:





3 June 2020.

Legend




24181260m

1 : 600

-20 0 20 40

Elevation (m

)

480

Offset (m)

460

440

Elevation (m

)

480

460

440

-40

℄L1000-LINE

0.6

11.3

14.115.7

21.822.6

25.323.3

512

212418

14

18

18

23

19

10

20

22

27

1717

171515

16

10

20

14

19111313

14

1110

88

16

15

17

17 41

37

m

TH19-LX-216WW LL

TS

CL

CL

BR

TS

CL

SP-SM

SP-SMML

CLBR

17.1

18

18

11

15

13

18

22

23

14

16

36

N PL

0.6

6.74.9

13.914.9

581271814

14

32

12

12

4R

23

R

24

2321

182114

2513

17

9

2025

18

15

15

33

29

18

m

TH19-LX-217N WW LLPL

TS

CL

SP-SMMLBR

0.6

12.814.9

17

14

1014

10

7

R

26

1213

13

148

27

25

19

m N

END

SM3

SM4

11

5

9.8

9

20

21

9

R

1610

17

13

23

7

W

TH19-LX-218W

END

END

SM3

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

1005+940


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

1:600

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 4

SHEET NO. 4 of 6





Notes:




by R.F. Binnie & Associates Ltd. CAD file 'ACAD-R3-336-L1000-1004+330 to 1006+000.dwg, received

3 June 2020.

Legend




24181260m

1 : 600

-40 -20 0 20 40

Elevation (m

)

480

Offset (m)

460

60 80

440

Elevation (m

)

480

460

440

-60 100

P e a c e

R i v e r

Highway

29

L1000-LINE

MNRL

℄

TS

BR

13.1

END

CL

0.3

26.1

4810181115201215

18

18

3R

27261841251723211921232827242212

2223

2119

19

3640

3746

49

1.59 / 1.520.67 / 1.281.52 / 5.101.94 / 5.27

1.06 / 4.33

0.55 / 2.67

0.92 / 3.51

4.53 / 5.88

m


Dia/Axial

(MPa)

CH

CL

GP-GC

0.11.6

8.3

18.5

12.4

END

2057

105

128

1115

3

26292227272728182214

24

17

55

42

N/A / N/AN/A / N/AN/A / N/A

1.01 / 2.740.87 / 2.831.98 / 2.07

5.61 / 4.43

m


Dia/Axial

(MPa)

ASPH GP-GM

6.7

BR

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

1006+420


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

1:600

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 4

SHEET NO. 5 of 6





Notes:




by R.F. Binnie & Associates Ltd. CAD file 'ACAD-R3-336-L1000-141-Model.dwg', received 20 May 2020.

Legend




24181260m

1 : 600

-20 0 20 40

Elevation (m

)

480

Offset (m)

460

60 80

440

Elevation (m

)

480

460

440

-40

P e a c e

R i v e r

MNRL

Highway

29

℄L1000-LINE

TS

CL

GP-GC

BR

0

5.86.7

12.4END

1315242010122347R

11105

11129857

19 35

m


ASPHGP

CL

CL

BR

0.10.81.2

5.8

8.8

11.912.8

26.2END

73634101011

8

1448RR

316122117182214

15

1914

15

15

19

38

37

28

m


CH

BR

0.21.6

14 END

Water Level8/9/2018

8RRR

414

1012

m


GC4

SM4

GM1VWP (4/3/2019)

N/A / N/A0.26 / 1.070.82 / 3.46N/A / N/A3.84 / 5.393.36 / 5.995.48 / 3.801.81 / 3.88

3.28 / 5.29

6.67 / 6.45

Is50Is50Dia/Axial

(MPa)

N/A / N/AN/A / N/AN/A / N/AN/A / N/A2.39 / 5.854.5 / 4.84

Is50Is50Dia/Axial

(MPa)

2.42 / 3.626.15 / 5.711.19 / 1.740.10 / 3.40

1.29 / 3.26

1.38 / 4.43

0.94 / 2.48

9.30 / 6.40

Is50Is50Dia/Axial

(MPa)

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

1006+900


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

1:600

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 4

SHEET NO. 6 of 6





Notes:



2. Not all instrumentation, groundwater levels, and slope inclinometer movement levels shown.


by R.F. Binnie & Associates Ltd. CAD file 'ACAD-R3-336-L1000-176-Model.dwg', received 20 May 2020.

Legend




24181260m

1 : 600

-20 0 20 40

Ele

va

tio

n (m

)

480

Offset (m)

460

440

Ele

va

tio

n (m

)

480

460

440

-40

℄L1000-LINE

2.5 m

1

1

1

1

1.0

2.5

Or To Suit

1.0

2.5

5.0 m

12.5 m

10°

25 Kg Riprap

Non-Woven Geotextile

N/A

PROJECTION:

N/A

DATUM:

SHEAR KEY - CONCEPT ONLY

1005+940


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052807.11

A

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2020

DATE:

SCALE:

EM

1:500

BB

HIGHWAY NO. 29

LYNX CREEK EAST


FIGURE 5





Notes:


by R.F. Binnie & Associates Ltd. CAD file 'ACAD-R3-336-L1000-1004+330 to 1006+000.dwg, received

3 June 2020.

Legend




100m 5

1 : 500

2015

Appendix B

Figures 6 to 26

Slope Stability Analyses

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN

SLOPE STABILITY ANALYSES

STA. 1004+440

LHS & RHS AT MNRL AND RAPID DRAWDOWN

HIGHWAY 29, BC

LYNX CREEK EAST SEGMENT

GEOTECHNICAL ASSESSMENT AND DESIGN FIGURE 6

R.F. BINNIE & ASSOCIATES LTD.

Wood Environment & Infrastructure Solutionsa Division of Wood Canada Limited (Wood)

3456 Opie Crescent

Prince George, BC, Canada V2N 2P9

Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1004+440

LHS & RHS USING UNDRAINED STRENGTH

PARAMETERS

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+260

LHS & RHS AT MNRL

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+260

LHS & RHS AT RAPID DRAWDOWN

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+260

LHS & RHS AT USING UNDRAINED STRENGTH

PARAMETERS

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+600

LHS AT MNRL AND RAPID DRAWDOWN (UPPER) USING

UNDRAINED STRENGTH PARAMETERS (LOWER)

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+820

LHS & RHS AT MNRL

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+820


HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+820


PARAMETERS

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+940

LHS AT MNRL AND RAPID DRAWDOWN

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1005+940

LHS AT MNRL USING UNDRAINED STRENGTH

PARAMETERS

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1006+200

LHS & RHS AT MNRL

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1006+200


HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1006+200


PARAMETERS

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1006+520

LHS & RHS AT MNRL

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1006+520


HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1006+520


PARAMETERS

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1007+000

RHS AT MNRL AND RAPID DRAWDOWN

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1007+000

RHS AT MNRL USING UNDRAINED STRENGTH

PARAMETERS

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1007+060

RHS AT MNRL AND RAPID DRAWDOWN

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

EM/LD JUNE 2020

NP KX052807.11

N/A A

N/A

AS SHOWN


STA. 1007+060

RHS USING UNDRAINED STRENGTH PARAMETERS

HIGHWAY 29, BC





3456 Opie Crescent


Tel. (250) 564-3243 Fax (250) 562-7045

CLIENT DWN BY:

CHK'D BY:

PROJECTION:

DATUM:

SCALE:

PROJECT

DATE:

PROJECT NO:

REV. NO.:

FIGURE NO:

CHK'D BY:

TITLE

Limitations

Project # KX052807.11 | 12 June 2020 Limitations

Limitations

1. The work performed in the preparation of this report and the conclusions presented are subject

to the following:

a. The Standard Terms and Conditions which form a part of our Professional Services

Contract;

b. The Scope of Services;

c. Time and Budgetary limitations as described in our Contract; and

d. The Limitations stated herein.

2. No other warranties or representations, either expressed or implied, are made as to the

professional services provided under the terms of our Contract, or the conclusions presented.

3. The conclusions presented in this report were based, in part, on visual observations of the Site

and attendant structures. Our conclusions cannot and are not extended to include those portions

of the Site or structures, which are not reasonably available, in Wood’s opinion, for direct

observation.

4. Where testing was performed, it was carried out in accordance with the terms of our contract

providing for testing. Other substances, or different quantities of substances testing for, may be

present on-site and may be revealed by different or other testing not provided for in our contract.

5. The utilization of Wood’s services during the implementation of any remedial measures will allow

Wood to observe compliance with the conclusions and recommendations contained in the report.

Wood’s involvement will also allow for changes to be made as necessary to suit field conditions as

they are encountered.

6. This report is for the sole use of the party to whom it is addressed unless expressly stated

otherwise in the report or contract. Any use which any third party makes of the report, in whole or

the part, or any reliance thereon or decisions made based on any information or conclusions in

the report is the sole responsibility of such third party. Wood accepts no responsibility whatsoever

for damages or loss of any nature or kind suffered by any such third party as a result of actions

taken or not taken or decisions made in reliance on the report or anything set out therein.

7. This report is not to be given over to any third party for any purpose whatsoever without the

written permission of Wood.

8. Provided that the report is still reliable, and less than 12 months old, Wood will issue a third-party

reliance letter to parties that the client identifies in writing, upon payment of the then current fee

for such letters. All third parties relying on Wood’s report, by such reliance agree to be bound by

our proposal and Wood’s standard reliance letter. Wood’s standard reliance letter indicates that in

no event shall Wood be liable for any damages, howsoever arising, relating to third-party reliance

on Wood’s report. No reliance by any party is permitted without such agreement.

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