GEOTECHNICAL ASSESSMENT AND DESIGN · Geotechnical Assessment and Design Halfway River Segment Project # KX052806 | 6/18/2019 Page 3 INTRODUCTION As part of BC Hydro’s proposed

Prepared for:

R.F. Binnie & Associates Ltd.

678 Vancouver Street Prince George, BC V2L 2P3 June 18, 2019

GEOTECHNICAL ASSESSMENT AND

DESIGN

Halfway River Segment

Highway 29, British Columbia

Project # KX052806

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

GEOTECHNICAL ASSESSMENT AND DESIGN


Highway 29, British Columbia

Project # KX052806

Prepared for: R.F. Binnie & Associates Ltd.

678 Vancouver Street Prince George, BC V2L 2P3

Prepared by: Wood Environment & Infrastructure Solutions,

a Division of Wood Canada Limited

3456 Opie Crescent Prince George, BC V2N 2P9

18 June, 2019

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Geotechnical Assessment and Design


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Table of Contents

INTRODUCTION ................................................................................................................................................................... 3

SCOPE ....................................................................................................................................................................................... 3

GENERAL PROJECT DESCRIPTION ................................................................................................................................ 4

BACKGROUND ...................................................................................................................................................................... 5

4.1 GEOLOGY ............................................................................................................................................................... 5

SITE CONDITIONS AND DISCUSSION ......................................................................................................................... 6

5.1 SUBSURFACE GEOLOGICAL CONDITIONS – HIGHWAY 29 REALIGNMENT ................................ 6

5.2 PREVIOUSLY DEVELOPED AREAS ................................................................................................................. 7

5.3 SHALE BEDROCK ................................................................................................................................................. 7

5.4 ACID ROCK DRAINAGE AND METAL LEACHING POTENTIAL ........................................................... 9

5.5 EXISTING HIGHWAY 29 ASPHALT THICKNESS ........................................................................................ 9

5.6 GROUNDWATER CONDITIONS ..................................................................................................................... 9

GEOTECHNICAL DESIGN CONSIDERATIONS & RECOMMENDATIONS ......................................................10

6.1 STRIPPING ............................................................................................................................................................10

6.2 SUBGRADE PREPARATION ............................................................................................................................10

6.3 TEMPORARY EXCAVATIONS .........................................................................................................................11

6.4 EMBANKMENT FILL CONSTRUCTION .......................................................................................................11

6.4.1 WESTERN APPROACH STA. 3000+580 TO 3000+950 (RIGHT) ......................................12

6.4.2 WESTERN APPROACH STA. 3000+580 TO 3000+900 (LEFT) ..........................................15

6.4.3 STA. 3002+300 TO 3002+800 .....................................................................................................16

6.5 CUT SLOPES .........................................................................................................................................................17

6.6 GEOTEXTILE AND BIAXIAL GEOGRID SPECIFICATIONS .....................................................................17

6.7 PAVEMENT STRUCTURE .................................................................................................................................18

6.8 WASTE DISPOSAL .............................................................................................................................................19

6.9 DETAILED GEOTECHNICAL RECOMMENDATIONS BY STATION SECTION ................................19

CLOSURE ...............................................................................................................................................................................22

REFERENCES .........................................................................................................................................................................23

List of Appendices

APPENDIX A FIGURES

APPENDIX B SLOPE STABILITY ANALYSIS (SLOPE/W)

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List of Tables

Table 5-1: Encountered Bedrock .................................................................................................................................................... 8

Table 5-2: Measured Asphalt Core Thickness ........................................................................................................................... 9

Table 5-3: Summary of Groundwater Monitoring ................................................................................................................ 10

Table 6-1: Summary of Subsurface Conditions (Sta. 3000+580 to 3000+950) ........................................................ 12

Table 6-2: Geotechnical Material Properties for Limit Equilibrium Slope Stability Analyses (Sta. 3000+580

to Sta. 3000+950) .............................................................................................................................................................................. 13

Table 6-3: Summary of Limit Equilibrium Slope Stability Analyses (Sta. 3000+580 to Sta. 3000+950) .......... 13

Table 6-4: Summary of Limit Equilibrium Slope Stability Analyses (Riprap Slope) ................................................. 14

Table 6-5: Geotechnical Material Properties for Limit Equilibrium Slope Stability Analyses (Sta. 3002+300

to 3002+800) ....................................................................................................................................................................................... 17

Table 6-6: Summary of Limit Equilibrium Slope Stability Analyses (Sta. 3002+300 to 3002+800) .................. 17

Table 6-7: Non-Woven Geotextile Specifications ................................................................................................................. 18

Table 6-8: Biaxial Polypropylene Geogrid Specifications .................................................................................................. 18

Table 6-9: Recommended Minimum Pavement Structure Thickness ........................................................................... 18

Table 6-10: Detailed Geotechnical Recommendations by Station Section ................................................................ 20

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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 3.7 km long segment of Highway 29 in the vicinity of the confluence of the Halfway River

with the Peace River. The general location is shown in Figure 1, and a plan of the proposed realignment is

provided on three map sheets in Figure 2.

Background terrain and geotechnical information for the project segment is described in a previous report

(Amec Foster Wheeler, 2012) prepared for the definition design phase. A summary of the geotechnical

subsurface investigations and the resulting data for the Halfway River realignment segment is presented

in a separate report (Wood, December 2019). Functional design phase geotechnical recommendations in

support of the proposed new Halfway River bridge crossing portion of the realignment segment are

described in a separate report (Wood, August 2018). Investigations specific to six adjacent granular

borrow prospect areas (Areas A through F) are also reported separately.

This report includes a description of the scope of services, methodology, a discussion of geotechnical

engineering analysis and geotechnical recommendations developed to support the detailed design for

the proposed highway alignment. The detailed design (analysis and reporting) of the bridge abutments

areas and piers is being reported separately.

SCOPE The scope of Wood’s geotechnical assessment was as described by tasks G-100 through G106, G-112 and

G114 in Section 1.4 of Site C Clean Energy Project, Engineering Design Services for Hwy 29 Road and

Bridge Infrastructure, Work Order Release 6 (Version 3 - July 4, 2016), pursuant to the Sub-Consultant

Agreement between R.F. Binnie Associates Ltd. and Amec Foster Wheeler Americas Limited, dated

October 6, 2016, and as subsequently amended on March 1, 2018 (Amendment No. 1 between Binnie and

Wood).

The geotechnical assessment included the following activities:

Attendance at project team meetings;

Review of relevant project background data;

Preparation of a site-specific health and safety plan for the field work;

Field reconnaissance to identify locations and access routes for the geotechnical investigation;

Development of multiple geotechnical site investigation plans and budgets for various phases of field

investigation;

Preparation of various site access plans and permit support information;

Procurement and coordination of subcontractor equipment and support services for the geotechnical

investigation work including utility location, tree fallers, Level 3 medical support with emergency

transport vehicle, an excavator contractor, traffic control, multiple drill rigs, as well as cone

penetration testing and downhole geophysical testing subcontractors;

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Coordination of the access preparation and geotechnical investigation work with concurrent activities

by others, including property considerations, surveyors, archaeology and environmental studies;

Supervision of several phases of geotechnical field investigation, including logging of ground

conditions, retention of soil samples from test pits, and retention of soil and rock core samples from

boreholes;

Supervision of the installation of groundwater instrumentation (vibrating wire piezometers) at select

locations, and follow-up monitoring;

Coordination and review of in-situ seismic piezo-cone (sCPTu) and downhole geophysics data

procurement;

Laboratory testing on selected soil and rock samples;

Geotechnical analysis to develop appropriate design recommendations, including the following

analyses:

Limit equilibrium slope stability analyses (using Slope/W) for current conditions, at maximum

normal reservoir level (MNRL), and after emergency drawdown,

Pore pressure response to emergency drawdown modelling using Seep/W;

Provision of interim geotechnical data reports and draft recommendations as required; and

Compilation of this report.

GENERAL PROJECT DESCRIPTION The proposed 3.7 km long Halfway River realignment segment is referenced as the L3000A20-Line (Binnie

draft geometric design drawings dated 31 March 2019) which runs north of and approximately parallel to

the existing Highway 29 alignment. The beginning or western end of the new alignment is at Sta.

2999+700, near the entrance to the BC Ministry of Transportation & Highways’ (BC MoTI) Tompkins Pit.

The eastern end of the new alignment is at Sta. 3003+400, along an existing tangent of Highway 29. The

new alignment would be above and generally to the north of the main Peace River reservoir shoreline. A

bridge on the order of 1 km long (approx. Sta. 3001+018 to Sta. 3002+060) is planned to span the

Halfway River valley, and its associated floodplain which will be fully inundated after reservoir filling. The

highway is to comprise two paved lanes.

On either side of the Halfway River valley, the new highway alignment would generally cross flat-lying

east-west oriented fluvial terrace terrain. However, there are steep terrace face slopes adjacent to the

proposed new alignment; the most significant of which are the eroded and exposed shale bedrock faces

along the current banks of the Halfway River. Reservoir inundation would result in the western approach

to the bridge being along the top of a relatively narrow remnant spit of land extending out into the

reservoir, with relatively steep slopes down into the reservoir on either side of the approach alignment

and below the bridge’s west abutment site. The east bridge abutment is adjacent to a relatively steep

existing eroded slope down into the Halfway River.

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

project segment, refer to our definition design report (Amec Foster Wheeler, 5 March 2012).

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BACKGROUND

4.1 GEOLOGY

Within the study region, the bedrock geology consists of Cretaceous marine sedimentary rock sequences

overlain by a series of glacial and fluvial Quaternary sediments (Hartman and Clague, 2008). The bedrock

units present include flakey and fissile shales and siltstone ascribed to the Shaftesbury Formation (part of

the Fort St. John Group), overlain by Dunvegan Formation sandstones and conglomerates (Hartman and

Clague, 2008 and Bidwell, 1999). The bedding in the bedrock has been reported as near horizontal (Klohn

Crippen Berger and SNC-Lavalin, 2003) in the vicinity of the project segment, but may exhibit local

undulation and variations.

The Shaftesbury shale typically is well bedded with thin, weak layers, some of which include bentonitic clays

from ash fall deposits that exhibit high plasticity and have low shear strength (Bidwell, 1999). Stability issues

in the shale have developed from weak cementation; valley rebound due to stress relief and movement

along pre-sheared or weak layers parallel to bedding.

Within the Halfway River segment, bedrock is exposed along the banks of the Halfway River upstream from

Highway 29 between elevation 464 m to 472 m ASL and is believed to underlie the terrace areas on both

sides of the river at similar elevations (Graeme and Murray, 1982). This bedrock is interpreted to be

interbedded shales and siltstones of the Shaftesbury Formation. Bedrock outcrops of interbedded shales

and siltstones were also noted adjacent to the current highway alignment as it crosses the slope between

terrace levels towards the east side of the project site.

The Quaternary-age sediments of the Peace River region are well exposed in the study area. The oldest

sediments present are pre-glacial fluvial deposits likely to occur on bedrock at the base of pre-glacial valley

bottoms. Listed by decreasing age, the younger sediments include advance phase fine-grained

glaciolacustrine soils (Glacial Lake Mathews), glacial tills of the last glaciations, late-glacial fine-grained

glaciolacustrine deposits (Glacial Lake Peace) and post-glacial deposits including fluvial sand, gravel and silt

deposits and landslide deposits (Hartman and Clague, 2008).

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SITE CONDITIONS AND DISCUSSION

5.1 SUBSURFACE GEOLOGICAL CONDITIONS – HIGHWAY 29

REALIGNMENT

The following sections present brief descriptions of the geotechnical ground conditions anticipated along

various design sections of the new highway alignment (L3000-Line), preceding in increasing survey

chainage order from west to east. These sections should be read in conjunction with the Geotechnical

Data Report (Wood, May 2019). Investigation locations are shown in Figure 2, and profile views with

simplified stick log representations are shown in Figure 3 (Sheets 1 to 12).

Sta. 2999+700 to 2999+840: This section is a transition off the existing Highway 29 alignment and will

comprise a series of low fills (<2 m) and cuts (<3 m) along the surface of a fluvial terrace. Below a thin

organic topsoil layer, compact to dense, fluvial, granular soils with variable distribution of sand and gravel

with cobbles are anticipated. The granular deposit was dry to moist and generally consisted of less than

5 % fines content (silt and clay particles less than 0.075 mm). Shale bedrock is not anticipated to be

encountered by the cuts, as the bedrock elevation is expected to be below 477.7 m.

Sta. 2999+840 to 3000+200: Comprises low (<2 m) fills and shallow ditch cuts (up to 2.5 m) across the

relatively flat fluvial terrace. Below a thin organic topsoil layer, compact to dense, fluvial, granular soils

with variable distribution of sand and gravel with cobbles are anticipated. The granular deposit was dry to

moist and generally had a 5% to 10% fines content (silt and clay particles less than 0.075 mm). Shale

bedrock was encountered in three test pits (TP17-A-005, TP17-A-006, and TP17-A-007) at elevation 477.3

m to 476.3 m. Generally, the underlying bedrock profile appears to dip towards the east.

Sta. 3000+200 to 3000+580: This section consists of minor fills (<3 m) to be constructed on the relatively

flat surface on the fluvial terrace. Soils underlying the embankment are anticipated to be thin organic

topsoil layer, over compact to dense deposit of fluvial, granular soils containing a variable distribution of

sand and gravel with cobbles. The granular deposit was dry to moist and contained 5% to 31% fines (silt

and clay particles less than 0.075 mm). Shale bedrock is anticipated to occur below elevations 476.3 m to

469 m. Generally, the underlying bedrock profile appears to dip towards the east.

Sta. 3000+580 to 3001+018: This section consists of a proposed embankment fill up to 15 m high. The

embankment is to be constructed partially on the relatively flat surface of a fluvial terrace and partially on

the south side slope of the terrace. This fill section ends at the west abutment of the proposed new

Halfway River bridge. Soils underlying the embankment area are anticipated to consist of a thin organic

topsoil layer over a compact to dense fluvial granular soils with variable distribution of silt. The granular

deposit was dry to moist and contained 5% to 35% fines content (silt and clay particles less than

0.075 mm). The exception was at test hole TH17-A, 003, TH17-A-022, TH17-A-023, and TH17-A-024,

encountered silt below the topsoil. The encountered granular fluvial deposits were in the order of 0.3 m

to 3.2 m thick, and silts are between 0.3 m and 1.7 m thick. The surficial soils are underlain by weathered

shale and shale bedrock at variable elevations ranging between approximately 466.9 m and 472.6 m.

Sta. 3001+018 to 3002+060: Represents the proposed new bridge crossing site for the Halfway River and

its flood plain.

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Sta. 3002+060 to 3002+500: This section consists of up to a 7 m high proposed embankment, with ditch

cuts up to 1.5 m to be constructed on the relatively flat fluvial terrace, which serves as the approach to the

eastern abutment for the new bridge across the Halfway River valley. The subsurface conditions are

anticipated to consist of a thin organic topsoil layer, over compact to dense fluvial granular soils with

variable distribution of sand, gravel with cobbles. The granular deposit was dry to moist and contained 5%

to 35% fines content (silt and clay particles less than 0.075 mm). The encountered fluvial deposits were in

the order of 4.1 m to 16.6 m deep, and are underlain by weathered shale and shale bedrock at variable

elevations ranging between approximately 458.4 m and 461.9 m.

Sta. 3002+500 to 3003+100: This section consists of up to a 4 m high embankment to be constructed on

a relatively flat fluvial terrace. The subsurface conditions are anticipated to consist of a thin organic topsoil

layer, over a cap of silt, silty sand, and high plasticity clay (up to 0.6 m thick). This fine-grained soil cap was

underlain by compact to dense fluvial granular soils with variable distribution of sand, gravel with cobbles.

The granular deposit was dry to moist and contained 5% to 15% fines content (silt and clay particles less

than 0.075 mm). The encountered granular deposits were greater than 4.5 m deep. Shale bedrock was not

encountered in the test pits.

Sta. 3003+100 to 3003+400: This section is a transition to the existing Highway 29 alignment and will

comprise a series of low fills (<3.3 m) and cuts (<1.2 m) along the surface of the fluvial terrace. The

subsurface conditions are anticipated to consist of a thin organic topsoil layer, over high plasticity clay (up

to 0.5 m thick). The high plasticity clay is underlain by compact to dense fluvial granular soils with variable

distribution of sand, gravel with cobbles. The granular deposit was dry to moist and contained 5% to 18%

fines content (silt and clay particles less than 0.075 mm). The encountered fluvial deposits were greater

than 3.9 m deep. Shale bedrock was not encountered in the test pits.

5.2 PREVIOUSLY DEVELOPED AREAS

The proposed alignment traverses areas of previous development that have shaped and influenced the

native surficial soil deposits. These areas consist of agricultural fields, residential and farm buildings,

related utility infrastructure, septic disposal fields, localized dump areas, and previously established

gravel/paved access roads.

Existing structures and their related infrastructure were noted along the alignment between

Sta. 3002+230 and 3002+370.

5.3 SHALE BEDROCK

Where bedrock was encountered during the investigation, it consisted of shale attributed to the

Shaftesbury Formation (part of the Fort. St. John Group). The Shaftesbury shale typically is well bedded

with thin, weak layers, some of which may include bentonitic clays from ash fall deposits that exhibit high

plasticity and have low shear strength. Stability issues in the shale have developed from weak

cementation, valley rebound due to stress relief and movement along pre-sheared or weak layers parallel

to bedding (Amec Foster Wheeler, 5 March 2012). Encountered shale bedrock locations and elevations

relative to the L3000-Line are summarized in Table 5-1.

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Table 5-1: Encountered Bedrock

ID Station

Bedrock Depth

(m)

Bedrock Elevation

(m)

TP17-A-005 3000+045.1 2.1 477.2

TP17-A-006 3000+115.3 1.2 477.3

TP17-A-007 3000+157.2 0.6 476.3

TP17-A-009 3000+300.3 1.8 474.0

TP17-A-010 3000+407.3 1.2 474.1

TH17-A-001 3000+499 2.4 473.0

TP17-A-011 3000+606.7 1.8 471.1

TP18-A-036 3000+606.8 0.4 469.0

TH17-A-002 3000+690.8 0.5 472.6

TH17-A-003 3000+728.3 0.5 468.5

TP17-A-012 3000+728.3 0.8 459.8

TH18-A-023 3000+813.6 1.1 454.3

TH18-A-022 3000+818 0.6 466.9

TH17-A-004 3000+877 3.3 470.7

TH18-A-024 3000+890.7 1.8 453.4

TP17-A-013 3000+899 0.9 472.6

TH18-A-025 3000+907.5 0.2 444.1

TH18-A-026 3001+021.1 2.4 470.2

TH17-A-005 3001+039 3.2 469.9

TH17-A-009 3002+010.5 4.1 461.9

TH18-A-021 3002+058.1 16.6 458.4

TH17-A-010 3002+103.2 14.4 460.0

TH17-A-011 3002+301.5 11.9 462.5

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5.4 ACID ROCK DRAINAGE AND METAL LEACHING POTENTIAL

In general, bedrock is anticipated to be below the limits of the planned excavations for the design

roadway alignment. However, sub-excavation of some weathered shale is likely for fill foundation

preparation right of the centerline between approximately Sta. 3000+700 and 3000+800. There may also

be some shale excavation/exposure related to the removal of surficial sands and gravels along slope

crests and in the vicinity of bridge end construction. To assess the Shale’s potential for acid rock drainage

(ARD) and metal leaching (ML), eight core samples from four drill holes (TH17-A-005, TH17-A-009, TH18-

A-021, and TH18-A-026) were selected for testing. The samples were sent to SGS Canada Inc. (SGS) in

Burnaby, BC for acid-base accounting (ABA) analysis and multi-element analyses, and quantitative X-ray

diffraction. The laboratory results can be found in the Geotechnical Data Report. The results indicate that

bedrock sequence had the potential for acid generation. It is recommended that all shale excavation for

the project be considered as potentially acid generating and be disposed of in an environmentally

appropriate manner. Should significant surface exposures of shale remain after excavation, it is likely that

they could be appropriately treated by backfill cover if required.

5.5 EXISTING HIGHWAY 29 ASPHALT THICKNESS

The results of the pavement drilling program along the existing pavement surface of Highway 29 are

provided inTable 5-2. Figure 4 depicts the coring locations.

Table 5-2: Measured Asphalt Core Thickness

5.6 GROUNDWATER CONDITIONS

Vibrating wire piezometers were installed to provide information on the long-term groundwater conditions

at the site. The details of the vibrating wire piezometers, along with maximum and minimum piezometric

levels in 2017 and 2018 are provided in Table 5-3. Further details on the instrumentation installation can

be found in the geotechnical data report (Wood, May 2019).

Hole ID Location Thickness

(mm) Hole ID Location

Thickness

(mm)

PV17-001 Eastbound/Centre 150 PV17-015 Eastbound/Centre 120

PV17-002 Westbound/Centre 180 PV17-016 Westbound/Centre 150












PV17-014 Westbound/Centre 180

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Table 5-3: Summary of Groundwater Monitoring

1. Possible installation or instrument irregularity. The piezometric level is not consistent with other piezometers installed in the shale or on nearby

project sites.

GEOTECHNICAL DESIGN CONSIDERATIONS &

RECOMMENDATIONS Based on the office and field investigations to date, there does not appear to be any significant

geohazards or geotechnical conditions that would preclude the construction of L3000A20 alignment as

proposed. Section 6.1 through Section 6.8 provide geotechnical recommendations that are generally

applicable for the design and construction of the new highway alignment. A summary of

recommendations specific to various station ranges is provided in Section 6.9. Recommendations are

based on specific base mapping data provided to Wood on 9 January 2018 and design alignment

L3000A20 provided on 31 March 2019 by Binnie. The following recommendations also reference the

Ministry of Transportation and Infrastructure’s 2016 version of the Standard Specifications for Highway

Construction (SS2016), which will be used for the project construction.

6.1 STRIPPING

For the purpose of design, unless indicated otherwise, a minimum average stripping depth of 300 mm

should be assumed at the base of the proposed fills. Additional areas (e.g. existing ditches and wet areas)

will require deeper stripping and/or sub-excavation of soft, wet, weakened and organic soils that are

unsuitable for fill foundations. All stripped foundation subgrades should be reviewed prior to fill

placement by a geotechnical engineer or their representative to confirm that underlying soft, wet,

weakened and organic soils have been appropriately removed, and that conditions are as anticipated in

this report. Some additional details regarding stripping and/or sub-excavation specific to various project

station ranges are provided in Section 6.9, below.

6.2 SUBGRADE PREPARATION

For the purposes of fill construction, the following subgrade preparation procedure is recommended:

Remove all unsuitable materials such as loose fill, organic materials, stripping, and softened soils

from the subgrade surface. Location-specific guidance for additional sub-excavation (in excess of

stripping) of subgrade soils is provided in Section 6.9 below. A geotechnical engineer should review

all prepared subgrade prior to placement of fill (and/or geotextile separators, where applicable) to

confirm that unsuitable soils have been adequately removed.

Crown the subgrade to promote drainage by providing a minimum cross fall of 2% as soon as

possible following exposure of the subgrade soils. This will help minimize softening of the fine-

Piezometer

No.

Elevation

Ground/Tip

(m)

Maximum

Measured

Piezometric

Level in 2017

Minimum

Measured

Piezometric

Level in 2017

Maximum

Measured

Piezometric

Level in 2018

Minimum

Measured

Piezometric

Level in 2018

TH17-A-001A 475.4/473.1 476.6 <473.1 (dry) <473.1 (dry) <473.1 (dry)

TH17-A-001B 475.4/431.5 489.11 447.91 447.11 446.61

TH17-A-004A 474.0/470.9 471.6 <470.9 (dry) 471.4 471.1

TH17-A-004B 474.0/435.0 435.1 435.0 435.0 435.0

TH17-A-006A 438.3/429.9 434.1 434.0 434.3 433.8

TH17-A-010A 474.4/460.4 462.1 461.7 462.7 461.7

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grained subgrade materials due to infiltration of surface water from precipitation events that occur

following exposure of the subgrade.

Minimize disturbance of the subgrade by limiting vehicle and construction traffic over the prepared

subgrade surface. If the subgrade surface is disturbed and becomes softened, removal of softened

soils and replacement with suitable fill will be required.

Deposits of unsuitable subgrade soils that are 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 geotextile

separator(s), biaxial geogrid layer(s), granular backfills and/or other methods.

6.3 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, however, 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.

6.4 EMBANKMENT FILL CONSTRUCTION

The following general recommendations are provided for fill construction.

All fill foundation preparation, fill placement and fill compaction operations should be observed by

qualified geotechnical engineering field personnel to confirm that the construction is in accordance

with the recommendations in this report and SS2016.

Existing organic materials and loose fill should be removed from the outside face of the existing fill

slopes and from under the footprint of any new fills prior to placing new fill.

Unless otherwise noted in Section 6.9, fill should consist of inorganic soils such as low plastic clay

and silt, glacial till, rock borrow or granular soils with moisture contents near the optimum moisture

content (as determined by laboratory moisture-density testing) such that they are conducive to

good compaction.

Maximum fill slope angles are dictated by both the type of fill material used and the type of

subgrade on which the fill is to be placed. Unless otherwise noted in Section 6.9, use a maximum

fill slope of 2H:1V for fill constructed of soil or rock having less than 20% fines (particles passing

0.075 mm sieve). It is anticipated that some sources of suitable, well graded granular borrow

material occurs within or near the project limits. Use of materials with greater than 20% fines for

fills on this project is not recommended, and such situations would need to be reviewed by a

geotechnical engineer on a case by case basis.

Positive surface drainage away from the existing highway pavement structure is to be maintained.

Fill placed on the outside of an existing granular pavement structure (e.g. SGSB) should be free-

draining granular material (having less than 5% passing 0.075 mm sieve) and extend a minimum

100 mm in elevation below the bottom of adjacent SGSB so as to not block internal drainage.

Drainage from under an embankment area should be directed to an exposed face of a ditch or a

subdrain system but should not be directed over the face of potentially unstable or erodible slopes

without additional armouring and/or riprap.

Fills that overlie seepage zones from existing fill or natural slopes will require field review by a

geotechnical engineer. These areas should be treated on a case by case basis.

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Fills that will overlie soft clayey subgrades or sensitive wet silty subgrades will require specific field

review by a geotechnical engineer. The encountered condition should be assessed on a case by

case basis with section-specific recommendations provided by a geotechnical engineer as needed.

Fill construction recommendation details are provided on a station by station basis in Section 6.9. However,

two significant areas of note are discussed below:

6.4.1 WESTERN APPROACH STA. 3000+580 TO 3000+950 (RIGHT)

The approach to the western abutment is to be constructed on top of a relatively narrow remnant spit of

land which will extend out into the reservoir. An embankment fill up to 15 m (right of centerline) with a

2H:1V fill slope is proposed for this section. The fill to the right of centerline would spill down the existing

colluvial slope towards the existing Highway 29 alignment and the Peace River. The existing slope has an

approximate slope angle between 4.3H:1V and 5H:1V, with a height of 26 m to 37 m (crest of existing

slope to existing highway level).

Based on completed sub-surface investigations in this area, the fill foundation materials are anticipated to

consist of a thin organic topsoil layer (0.1 m to 0.4 m), below the topsoil is a mixture of silt and/or silty

sand with the exception of TP18-A-036 where residual soil and highly weathered shale is encountered

directly below topsoil. The thickness of highly weathered to residual shale varies throughout this section.

See Table 6-1 for a summary of subsurface conditions.

Table 6-1: Summary of Subsurface Conditions (Sta. 3000+580 to 3000+950)

Hole ID Test Hole Topsoil Silt Granular Soils Residual

Soil/Highly

Weathered

Shale

Moderately

Weathered to

Fresh Shale

3000+606.8 TP18-A-036 0.4 - - 0.4->1.2 -

3000+728.3 TP17-A-012 0.2 - 0.2-0.8 (SM3) 0.8->2.7 -

3000+728.3 TH17-A-003 0.1 0.1-0.4 (ML) - 0.5-4.6 4.6->15.2

3000+818 TH18-A-022 0.2 0.2-0.6 (ML) - 0.6-4.4 4.4->9.0

3000+813.6 TH18-A-023 0.1 0.1-0.6 (ML) 0.6-1.1 (SM3) 1.1-3.4 3.4->10.6

3000+890.7 TH18-A-024 0.1 0.1-1.8 (ML) - 1.8-3.8 3.8->25.8

Note: Soil classifications based on the MOTI Soil Classification System.

To assess the suitability of the proposed alignment and possibly required stability improvement measures,

limit equilibrium slope stability analyses were undertaken at four locations along the proposed

embankment section. The geometry of the slope and the stratigraphy was based on available survey and

embankment geometry provided by Binnie and subsurface information obtained during the geotechnical

field investigation. Potentially weak horizontal shale layers were included in the stability models for the

sections analyzed. The elevations of the weak shale layers were determined using information from the

detailed rock core logs and downhole geophysics. To confirm the geotechnical properties used in the

limit equilibrium analysis for the weak layer were appropriate (i.e. not too low), a back analysis was

undertaken for a section of the steep but unfailed slope. The result of the back analysis confirmed that the

angle of internal friction for the weak layer was a reasonable assumption, yielding a factor of safety

greater than 1. A summary of the parameters used in the stability analysis is provided in Table 6-2.

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Table 6-2: Geotechnical Material Properties for Limit Equilibrium Slope Stability Analyses (Sta. 3000+580 to Sta.

3000+950)

Where the failure of a slope would affect highway operation (i.e. a potential failure envelope encroaches

the paved surface, a failure causes lane closures, or failure might necessitate excessive maintenance),

minimum factors of safety under static loading conditions in accordance with Table 6.2b of the BC

MoTI (British Columbia Ministry of Transportation and Infrastructure) Supplement to CHBDC (Canadian

Highway Bridge Design Code) S6-14 were applied. The minimum required factor of safety for global slope

stability for a typical consequence slope with a typical degree of understanding is 1.54, assuming a

reservoir at maximum normal reservoir level (elev. 461. 8 m). The minimum required factor of safety for

the emergency drawdown scenario for the reservoir is 1.24. The geotechnical design criteria for the rapid

drawdown scenario used in the stability analyses was as follows; elevation 461.8 m to 452.5 m at

approximately 4.5 m per day, then to 444 m at 2.5 m per day.

The results of the limit equilibrium analyses are summarized in Table 6-3 below, with the graphical output

of the results provided in Appendix B.

Table 6-3: Summary of Limit Equilibrium Slope Stability Analyses (Sta. 3000+580 to Sta. 3000+950)

Design Case Required

FOS 3000+750 3000+830 3000+899 3000+940

Maximum

Normal

Reservoir

Level

As per L3000A20 design

1.54

1.36 1.20 1.35 1.38

- Upper Slope 2.1H:1V to

2.5H:1V

- 4 m to 5 m Bench at

463 m with 1.75H:1V

slope

- sub-ex 2 m to 4 m

1.54 1.54 1.54 1.54

Emergency

Drawdown

- Upper Slope 2.1H:1V to

2.5H:1V

- 4 m to 5 m Bench at

463 m with 1.75H:1V

slope

- sub-ex 2 m to 4 m

1.24 1.46 1.43 1.44 1.40

The resulting factors of safety for potential failures towards the reservoir were less than the target factor

of safety in the case of long-term (full reservoir) analysis for Stations 3000+750, 3000+830, 3000+899 and

3000+940 for the original design alignment embankment configuration. The factors of safety at these four

stations can be improved by excavating all silt, clay and/or a portion of highly weathered shale (residual

soil) that will underlie the embankment footprint and replacing it with free draining granular fill, as well as

some modifications to the fill slope geometry. The revised configuration includes an upper slope with a

Soil Type

Unit

Weight

(kN/m3)

Limit Equilibrium Shear

Strength Model

Cohesion

(kPa)

Angle of Internal

Friction (°)

Embankment Sand and

Gravel Fill 21 Mohr-Coulomb 0 30-36

Sand and Gravel 21 Mohr-Coulomb 0 37

Weak Shale Layers 24 Mohr-Coulomb 0 16

Slightly Weathered to

Fresh Shale 24 Anisotropic Strength 75

45 (vertical)

35 (horizontal)

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fill slope angle of 2.1H:1V to 2.5H:1V, and a toe berm at 463 m, as per image extracted from slope stability

analysis, below. The toe berm is typically 5 m wide and has a fill slope of 1.5H:1V to 1.75H:1V. All organics,

colluvium (silts) and up to 2 m to 3 m of the underlying weathered shale should be sub-excavated.

Landslide generated wave modelling undertaken by Northwest Hydraulic Consultants (NHC) indicates that

the embankment below elevation 464 m requires riprap protection. Slope stability analysis was

undertaken to ensure that the addition of riprap protection does not negatively impact the global stability

of the embankment. The geometry of the riprap protection was based on information provided by NHC.

The results of the limit equilibrium analyses are summarized in Table 6-4- below, with the graphical

output of the results provided in Appendix B.

Table 6-4: Summary of Limit Equilibrium Slope Stability Analyses (Riprap Slope)

Riprap

Slope

Riprap Crest

Elevation (m)

Sub-excavation Depth (m) FOS of Riprap Slope

(Maximum Normal Reservoir

Level)

2H:1V 464.9 1.5 m 1.55

1.75H:1V 464.3 2.0 m (riprap to be embedded

1 m below original ground level)

1.54

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Based on the investigation and analyses performed to date, the following specific recommendations are

provided for embankment construction at this location:

The embankment footprint should be stripped of organic topsoil and any other unsuitable (soft or

wet) foundation soils and shaped to promote drainage.

All silt and clay, or highly weathered shale (residual soil) will need to be sub-excavated during

construction. A sub-excavation of up to 3 m is anticipated but is subject to field review by a geotechnical

engineer.

The stripped and prepared subgrade should be reviewed and approved by a geotechnical engineer

prior to further construction. The geotechnical engineer will give direction as to required further

improvements if any.

All final exposed/prepared shale subgrades should be protected from water and disturbance by

construction equipment, and be backfilled with a minimum 0.3 m cover of granular fill within 24 hours

to reduce the potential for the exposed shale to become weakened by disturbance and/or slaking.

The upper embankment fill slope (above elevation 463 m) should be placed no steeper than 2.5H:1V.

The lower embankment fill slope (below elevation 463 m) should be placed no steeper than 1.75H:1V.

Embankment fill below elevation 466 m should consist of clean granular fill with less than 5% fines.

Above elevation, 466 m fill can consist of Type D borrow with less than 20% fines,

The fill and natural slope below elevation 466 m should be provided with riprap protection.

The riprap should be placed no steeper than 1.75H:1V. The riprap should be keyed into the original

ground by a minimum of 1 m. Sub-excavation under the riprap slope is expected to be similar to that

for the adjacent fill area, in the order of 2 m, and subject to field review by a geotechnical engineer.

6.4.2 WESTERN APPROACH STA. 3000+580 TO 3000+900 (LEFT)

The terrain to the left of this proposed alignment section is comprised of relatively flat-lying ground

adjacent to the approximately 38 m high, over-steepened (50 to 60 degree) eroded shale slope down to

Halfway River. Embankment fills up to 6.7 m (left of centerline), are proposed for this section, the toes of

which would be on the order of 35 m to 46 m south of the crest of the slope. Based on completed sub-

surface investigations in this area, the fill foundation materials are anticipated to consist of a thin organic

topsoil layer, over a compact to dense layer (0.6 m to 2.7 m thick) of fluvial, granular soils containing a

variable amount of silt, sand and gravel with cobbles. There is a variable thickness of underlying

weathered shale throughout this section. Borehole geophysics and detailed core logging indicated the

presence of a potentially weak clay layer at elevation 433 m to 435 m, near the toe of the existing slope.

Stability and required setback or stability mitigation measures were assessed for a previous L3000A08-

geometric alignment, which was closer to the crest of the slope. To determine the required setback or

mitigation measures required, limit equilibrium slope stability analyses was undertaken. The results of the

stability analysis indicated the factors of safety for failures towards Halfway River were less than the target

factor of safety in the case of long-term (full reservoir) analysis for Station 3000+600 and in the

emergency drawdown case for Stations 3000+600, 3000+700 and 3000+800. The factors of safety at

these three stations could be improved by shifting the alignment to the south away from the crest of the

slope, unloading the crest, or constructing a berm at the toe of the slope. Graphical outputs of the

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stability analyses undertaken for this previous alignment are provided in Appendix B. To achieve the

required stability criteria in this area, the decision was made to shift the alignment to the south. The

current L3000A20-line alignment is located at an offset from the crest of the Halfway River slope at least

equal to or greater than the lateral shifts needed for the previous L3000A08 alignment to achieve the

required minimum factors of safety.

Based on the investigation and analyses performed to date, the following specific recommendations are

provided for embankment construction on the left side of the alignment:

The embankment footprint should be stripped of organic topsoil and any other unsuitable (soft or

wet) foundation soils and shaped to promote drainage.

The stripped and prepared subgrade should be reviewed and approved by a geotechnical engineer

prior to further construction. The geotechnical engineer will give direction as to further required

improvements if any.

The approved subgrade should be protected from disturbance by construction equipment.

Embankment fill should be placed no steeper than 2H:1V.

6.4.3 STA. 3002+300 TO 3002+800

A relatively minor embankment (up to 4 m in height) is proposed for this section, however, this segment

will run adjacent to a natural terrace slope which will be subject to inundation by the reservoir.

Accordingly, an assessment of the stability of this slope under MNRL and emergency drawdown

conditions was carried out to determine if any alignment adjustments or mitigation measures were

required. Wood conducted limit equilibrium slope stability analyses at two slope locations along the

proposed realignment segment, using Slope/W. The geometry of the slope and the stratigraphy was

based on available survey and embankment geometry provided by Binnie and subsurface information

obtained during the field investigation. Potentially weak shale layers were included in the stability model.

The elevations of the weak shale layers were determined using information from the detailed rock core

logs and downhole geophysics based on one borehole (TH17-A-021). A summary of the parameters used

in the stability analysis is provided in Table 6-5, and the results are attached in Appendix B.

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Table 6-5: Geotechnical Material Properties for Limit Equilibrium Slope Stability Analyses (Sta. 3002+300 to 3002+800)

The same design criteria was used, as stated in Section 6.4.1. The stability analysis for the rapid drawdown

assumed that the stabilizing effect of the water on the slope face is lost, but the pore pressures within the

slope remain high with no pore-water behaviour dissipation occurring (i.e. fully undrained behaviour as a

preliminary worst-case assessment). The results from the analysis are provided in Table 6-6 .

Table 6-6: Summary of Limit Equilibrium Slope Stability Analyses (Sta. 3002+300 to 3002+800)

The calculated factor of safety was above the target factor of safety for all cases analyzed.

6.5 CUT SLOPES

Only relative minor ditch cuts of up to 3 m will be required for the currently proposed alignment. With the

exception of topsoil and some relatively thin fine-grained soil caps, the required cuts are expected to

encounter mainly granular glaciofluvial and alluvial soils (BCMoTI Type D excavation) that are generally

anticipated to be suitable for use in the construction of new highway embankments. For detailed design,

the following recommendations are provided:

Unless otherwise specified in Section 6.9, use a maximum cut slope angle of 2H:1V.

Cuts that encounter seepage require field review by a geotechnical engineer and may need to be

protected from piping erosion by placement of a granular drainage blanket on the face of the slope

from the base of the ditch to a minimum of 2 m above the seepage zone.

Fine-grained cut materials within the project alignment are unsuitable for re-use and should be

considered waste.

Cut areas should be hydro-seeded with an appropriate vegetation seed mix as soon as possible

after soil disturbance is complete.

6.6 GEOTEXTILE AND BIAXIAL GEOGRID SPECIFICATIONS Where non-woven geotextiles are required, the recommended specifications listed in Table 6-7, below

should be used.

Soil Type

Unit

Weight

(kN/m3)

Limit Equilibrium Shear

Strength Model

Cohesion

(kPa)

Angle of Internal

Friction (°)

Embankment Sand and

Gravel Fill 21 Mohr-Coulomb 0 36-38

Clay/Silt Effective Stress 19 Mohr-Coulomb 0 22

Sand and Gravel 20.5 Mohr-Coulomb 0 35-36

Weak Shale Layers 24.5 Mohr-Coulomb 0 16

Weathered Bedrock 24.5 Mohr-Coulomb 0 30

Slightly Weathered to

Fresh Shale 24.5 Anisotropic Strength 50

45 (vertical)

35 (horizontal)

Station Scenario Target FS Calculated FS

Failure towards Peace River

3002+300 Maximum Normal Reservoir Level 1.54 2.33

Drawdown 1.24 2.18

3002+800 Maximum Normal Reservoir Level 1.54 2.48

Drawdown 1.24 2.31

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Table 6-7: Non-Woven Geotextile Specifications

2. Elongation > 50%, as per ASTM D4632

3. Based on minimum average roll values (as per ASTM C 4759) in the weaker principal direction

4. Based on maximum average roll values

Where geogrid is required for local subgrade improvement during construction, the recommended

specifications for a biaxial polypropylene geogrid are provided in Table 6-8, below.

Table 6-8: 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 4.0 +/- 0.1 m 1. Based on minimum average roll values (as per ASTM C4759).

6.7 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 6-9 provides a recommended pavement structure for the

new highway alignment, for two different subgrade conditions (Type A for well-drained granular

subgrades, Type B for poorly drained and/or fine-grained subgrades).

Table 6-9: Recommended Minimum Pavement Structure Thickness

It is currently anticipated that the recommended Type B structure would be used for the entire alignment

segment. However, in cases where subgrade fill soils meet the gradation for SGSB, the thinner Type A

structure can be substituted. Additionally, where new pavement structures will abut existing pavement

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 ≥ 630 N

Tear Strength2 ASTM D 4533 ≥ 350 ≥ 250 N

Puncture Strength2 ASTM D 6241 ≥ 1925 ≥ 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

Subgrade Type Pavement

Structure Asphalt (AP)

Crushed Base

Course 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 mm

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structures, the new SGSB thickness should match or exceed that of the existing structure to not hinder

drainage.

6.8 WASTE DISPOSAL The following procedures are recommended for siting and placing waste from unsuitable or surplus soil

materials generated by the project:

Waste materials should only be placed on slopes with a gradient of 10° (approx. 5.7H:1V) or less

and should not be placed in the vicinity of the crests of other slopes where they could have a de-

stabilizing influence.

Do not 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).

Up to a maximum height of 3 m waste materials should be placed with a maximum slope of 3H:1V.

Place the waste in maximum 1 m thick lifts and level with tracked equipment, as required.

Do not site waste piles adjacent to existing and proposed road fills, where practicable. Waste piles

placed adjacent to road fills are often encountered during future road widening and upgrading

projects, frequently leading to costly removal (and schedule delays) during construction.

Waste piles placed adjacent to road fills should not block drainage from existing fills and should be

kept at least 1 m below existing or proposed road pavement structure subgrade and/or any other

granular fills that are likely to transmit drainage.

Contour the waste material to promote surface drainage. To maintain positive drainage from the

fill surface while allowing for long-term settlement of the loosely placed fill, use a minimum 10%

cross fall slopes to crown the waste material.

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 the main Peace River

Valley sidewall slope located above and to the north of the proposed alignment options and/or along the

crests of the slopes down to the Halfway River, as these areas already show signs of instability. Also, waste

material should not be disposed of between the toes of the embankments and the future reservoir shoreline.

6.9 DETAILED GEOTECHNICAL RECOMMENDATIONS BY STATION SECTION

A summary of geotechnical conditions encountered, and station specific recommendations are provided

in Table 6-10 on the following pages.

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Table 6-10: Detailed Geotechnical Recommendations by Station Section

Station Range Reference Geometric Design

Configuration

Representative Geotechnical

Investigation Anticipated Subsurface Conditions Geotechnical Recommendations Left (North) Side Right (South) side

From To From To

2999+700 2999+840 2999+700 2999+840

Scratch Grade

Transition off existing Highway 29

Shallow fills (<2 m)

4H:1V Fill Slopes

TP17-A-001,

TP17-A-002,

Upper 0.2 m: topsoil

Below topsoil: silty gravel which extends to at least

3.7 m.

Shale bedrock not encountered.

Groundwater not encountered.

Stripping: Existing road ditch 0.5 m, side slopes

0.2 m

Max Fill Slope: 2H:1V

2999+840 3000+200 2999+840 3000+200

Scratch Grade

Transition off existing Highway 29

Shallow fills (<2 m) and ditch cuts

up to 2.5 m.

3H:1V Cut Slopes and,

4H1:1V Fill Slopes

TP17-A-003,

TP17-A-004,

TP17-A-005,

TP17-A-006,

TP17-A-007

Top of the fluvial terrace.

Upper 0.1 to 0.2 m: topsoil

Below topsoil: typically gravel, and gravel and sand

with varying silt contents extending to at least 2.1 m).

Test Pit TP17-A-007 encountered sand and silt below

topsoil extending to 0.6 m.

Shale bedrock encountered was encountered in three

test pits; TP17-A-005 (2.1 m),

TP17-A-006 (1.2 m), and TP17-A-007 (0.6 m).

Groundwater encountered in two test pits: TP17-A-

003 (3.7 m), TP17-A-004 (3.5 m).

Stripping: Typically 0.2 m, but locally deeper

(0.6 m) where sand and silt is encountered

between approx Sta. 3000+100 and 3000+200.

Max Fill Slope: 2H:1V, use granular fill.

Max Cut Slope 2H:1V (approximate 75% waste)

3000+200 3000+580 3000+200 3000+650 Fills (7 m)

2H:1V to 4H:1V Fill Slopes

TP17-A-008,

TP17-A-009,

TP17-A-010,

TP17-A-011,

TP18-A-035,

TP18-A-036,

TH17-A-001

Top of fluvial terrace.


Below topsoil: generally, gravel and/or sand with

varying amounts of silt.

Shale bedrock encountered at varying depths from

0.4 m and 2.4 m. Bedrock was not encountered in

TP17-A-008 and TP17-A-035.

Groundwater was not encountered.

Stripping: Typically 0.2 m.

Max Fill Slope: 2H:1V, use granular fill.

3000+580 3001+018 3000+650 3001+018

Fill up to 6.7 m (left of centerline)

and up to 15 m (right of

centerline). Fill increasing to the

east.

2H:1V Fill Slopes

TP17-A-013,

TH17-A-002,

TH17-A-003,

TH17-A-004,

TH17-A-005,

TH18-A-022,

TH18-A-023,

TH18-A-024,

TH18-A-025,

TH18-A-026

CPT17-A-001


Below topsoil: generally, silts, sands and/or gravel

with varying amounts of silt to top of bedrock.


0.5 m and 3.3 m.


Stripping: Typically 0.6 m.

Potential requirement for sub-excavation of

overburden and weathered shale (up to 3.0 m)

under footprint of embankment on slope to right

of centerline between Sta. 3000+700 to

3000+800.

Geotechnical Engineer to review subgrade at the

time of construction.

Max Fill Slope: See Section 6.4.1 and Section 6.4.2

for detailed discussions.

3001+018 3002+060 3001+018 3002+060 Bridge Refer to Bridge Report (Wood, Dec. 2018)

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Station Range Reference Geometric Design

Configuration

Representative Geotechnical

Investigation Anticipated Subsurface Conditions Geotechnical Recommendations Left (North) Side Right (South) side

From To From To

3002+060 3002+500 3002+060 3002+500

Fills up to about 7 m high on the

fluvial terrace near east bridge

approach, getting smaller to the

east. Ditch cuts up to 1.5m


3H:1V to 4H:1V Cut Slopes

TP17-A-016,

TP17-A-017,

TP17-A-019,

TP17-A-020,

TH17-A-009

TH17-A-010,

TH17-A-011,

TH18-A-021,

CPT17-A-005

Sand and gravel terrace. Over existing farming fields

and/or access road. Possible local surficial pockets of

old topsoil, old fill.

Upper 0.2 m to 0.6 m: topsoil

Below topsoil: generally, sand and gravel to the top

of bedrock. TP17-A-017 and TP17-A-019

encountered a thin 0.1 m to 0.2 m silt layer beneath

the topsoil.


4.1m to 14.4 m.

Groundwater encountered at 11.9 m in TH17-A-010.

Stripping: typically 0.2 to 0.4 m, the potential for

some locally deeper pockets of organics, silt cap

and/or old fills that may need sub excavation.

Will require removal of building foundations,

local fills, buried infrastructure, septic field(s) etc.,

including possible well decommissioning.

Max Fill Slope 2H:1V, use granular fill.

Max Cut Slope 2H:1V (approximate 75% waste)

3002+500 3003+100 3002+500 3003+100

Alignment generally parallel to and

north of terrace slope face then

merges to join the existing

Highway 29 alignment. Cut and fill

construction near the existing

ground level. Minor fills up to 3.4

m, and ditch cuts up to 1.3 m.



TP17-A-023,

TP17-A-025,

TP17-A-027,

TP17-A-030

Sand and gravel terrace with a silt cap. Over existing

farm access road and fields

Upper 0.2 m to 0.3 m: topsoil.

Below topsoil: 0.1 to 0.6 m high plasticity silt and clay,

then sand and gravel to the extent of the depth of

test pits (3.5 m to 4.5 m).



Strip typically 0.4, with locally deeper locations to

0.8m where silt and clay encountered.


Max Cut Slope 2H:1V (approximate 75% waste).

3003+100 3003+400 3003+100 3003+400

Transition onto existing Highway

29 alignment.

Minor fills up to 3.3 m, and ditch

cuts up to 1.2 m.



TP17-A-033,

TP17-A-034

Existing ditch and Highway 29

Upper 0.3 m: topsoil.

Below topsoil: 0.5 m high plasticity clay, then gravel

to end of the test pit (3.4 m to 3.9 m).



Strip 0.1 m of topsoil, potentially deeper to 0.5 m

in the ditch bottom.


Max Cut Slope 2H:1V (approximate 75% waste).

FINAL

DRAFT



Project # KX052806 | 6/18/2019 Page 22

CLOSURE The realignment segment referenced is the L3000A20-Line in R.F. Binnie & Associates Ltd.’s (Binnie) draft

geometric design drawings dated 8 March 2018.

This report was prepared for the exclusive use of R.F. Binnie & Associates Ltd., BC Hydro and the BC

Ministry of Transportation and Infrastructure for specific application to the project area described herein.

Any use which a third party makes of this report, or any reliance on or decisions made based on it, are the

responsibility of such third parties. Wood accepts no responsibility for damages, if any, suffered by any

third party as a result of decisions made or actions based on this report. It has been prepared in

accordance with generally accepted soil and foundation engineering practices. No other warranty,

express or implied, is made.

Respectfully Submitted,

Wood Environment & Infrastructure Solutions

a Division of Wood Canada Limited

Reviewed by:

Kim Sinclair, P.Eng. Nick Polysou, P.Eng.

Geotechnical Engineer Principal Geotechnical Engineer FINAL

DRAFT



Project # KX052806 | 6/18/2019 Page 23

REFERENCES Amec Foster Wheeler. (5 March 2012). Preliminary Geotechnical Assessment, Proposed Halfway River

Segment, Highway 29, Definition Design.

BGC Engineering Inc. (2012). BC Hydro, Site C Clean Energy Project, Preliminary Reservoir Impact Lines.

Bidwell, A.K., May 1999, “The Engineering Geology of the Fort St. John Area”, Master of Engineering

Report, University of Alberta.

British Columbia Ministry of Transportation and Infrastructure. (2016), Bridge Standards and Procedures

Manual, Supplement to CHBDC S6-14.

Graeme & Murray Consultants Ltd., January 1982, “Highway 29 Relocation, Hudson Hope to Charlie Lake

Section 1”, Technical Report.

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.

Klohn Crippen Berger and SNC-Lavalin Inc., January 2003, “Peace Cascade Development, Prefeasibility for

a Cascade of Low Consequence Structures as an Alternative to Site C”, Technical Report.

MoTI. (Adopted July 1, 2016). 2016 Standard Specifications for Highway Construction.

Wood Environment and Infrastructure Solutions. (22 May 2019). Draft Geotechnical Data Report, Halfway

River Segment, Highway 29, British Columbia.

Wood Environment and Infrastructure Solutions. (21 December 2018). Highway 29, Halfway River

Crossing, Halfway River Bridge Functional Design.

Wood Environment and Infrastructure Solutions. (3 January 2019). Highway 29, Halfway River Segment,

Alignment Geotechnical Functional Design.

FINAL

DRAFT

Appendix A

Figures

FINAL

DRAFT

DesignAlignment

Hwy 29

'A''B'

'C''D'

'E'

'F'Attachie

P e a c e R i v e r

Ha

l f wa

y

R i v e r

Farrell Creek

Notes:1. L3000A20 centreline alignment provided by R.F. Binnie & Associates Ltd. CAD file 'ALIGEOMPROF-16-0091.dwg', received 31 March 2019.2. Image provided by Bing Maps Road - © 2018 Microsoft Corporation © 2018 HERE.

LegendL3000A20 Centreline Alignment

Borrow Investigation Area'A'

!(

!(

!(

!(

!(

_̂

VancouverKamloops

ChetwyndFort St John

PrinceGeorge

ProjectLocation

This drawing was originally produced in colour.

CLIENT:

S:\Internal\KX052806-HalfwayRiver-GIS\HR-AlignGeotechInv-Det-Fig1-SiteLocPlan.mxd

SCALE:

PROJECTION:

DATUM:

CHK'D BY:

DWN BY: TITLE:

PROJECT:REV NO.:

PROJECT NO.:

DATE:

HIGHWAY NO. 29HALFWAY RIVERUTM Zone 10

NAD 83

KS

BB SITE LOCATION PLANGEOTECHNICAL INVESTIGATION

-

FIGURE 1

KX052806

JUNE 2019

$

1:75,000

0 1 2 3 40.5km

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.

FINAL

DRAFT

FIGURE 21 of 3SHEET NO.

2999+600 2999+8003000+000

3000+200

3000+400

3000+6003000+800

CONSTRUCTIONSTA. 2999+661.748LIMIT OF

!A

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")")

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")

")

")

")

!A

!A

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To Hudson'sHope H a l f w a y R i v e r

P e a c e R i v e r

Highway 29

TP18-A-035

TP18-A-036TH18-A-022

TH18-A-023

TH17-A-001

TP17-A-001

TP17-A-002TP17-A-003

TP17-A-004TP17-A-005

TP17-A-006

TP17-A-007

TP17-A-008

TP17-A-009

TP17-A-010

TP17-A-011

TH17-A-002

TH17-A-003

TH17-A-004

TP17-A-012

TP17-A-013

West AbutmentSta. 3001+018

1 2 3

SCALE:

PROJECTION:

DATUM:

CHK'D BY:

DWN BY:


CLIENT: DATE:JUNE 2019

-

PROJECT NO.:

REV NO.:

SITE PLANGEOTECHNICAL INVESTIGATION

HIGHWAY NO. 29HALFWAY RIVER

TITLE:

PROJECT:

UTM Zone 10

NAD 83

KS

BB

S:\Internal\KX052806-HalfwayRiver-GIS\HR-AlignGeotechInv-Det-Fig2-SitePlan.mxd

KX052806

1:4,000

0 50 100 150 20025m

$

Notes:1. L3000A20 centreline alignment provided by R.F. Binnie & Associates Ltd. CAD file 'ALIGEOMPROF-16-0091.dwg', received 31 March 2019.2. Maximum Normal Reservoir Level (461.8 m) downloaded from BC Hydro SharePoint 11 April 2018.3. Main view (foreground) and inset (foreground) orthophoto imagery provided by BC Hydro 9 January 2018.4. Main view (background) and inset (background) orthophoto imagery provided by Bing Maps Aerial - © 2018 Microsoft Corporation © 2018 DigitalGlobe ©CNES (2018) Distribution Airbus DS.

Legend!A Alignment Test Hole Location") Alignment Test Pit Location

#* Alignment CPT Location

L3000A20 Centreline Alignment

Maximum Normal Reservoir Level (461.8 m)

1:45,000


a Division of Wood Canada Limited (Wood)Wood Environment & Infrastructure Solutions

BC HYDRO c/o R.F. BINNIE & ASSOCIATES LTD.

FINAL

DRAFT


3000+6003000+800 3001+000 3001+200 3001+400 3001+600 3001+800 3002+000 3002+200

3002+4003002+600

#* #*#*

#*#*

!A

!A

!A

!A

!A !A

!A!A !A !A

!A

")

")

")

")

")") ")

")

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!A !A !A!A !A

!A !A !A!A

!A

!A

!A

!A

!A

!A

!A

")

")")

H a l f w a y R i v e r

Highway 29

TP18-A-035

TP18-A-036TH18-A-012

TH18-A-013 TH18-A-014 TH18-A-015 TH18-A-016 TH18-A-017 TH18-A-018 TH18-A-019 TH18-A-020

TH18-A-021

TH18-A-022

TH18-A-023TH18-A-024

TH18-A-025

TH18-A-026

TH18-A-027

TP18-A-037

TH17-A-001

TP17-A-010

TP17-A-011

TH17-A-002

TH17-A-003

TH17-A-004

TH17-A-005 TH17-A-006TH17-A-007

TH17-A-008 TH17-A-009 TH17-A-010TP17-A-012

TP17-A-013

TP17-A-016 TP17-A-017CPT17-A-001 CPT17-A-002 CPT17-A-003 CPT17-A-004

CPT17-A-005

TH17-A-011

TP17-A-019TP17-A-020

TP17-A-023

West AbutmentSta. 3001+018

East AbutmentSta. 3002+060

CLCL

1 2 3

SCALE:

PROJECTION:

DATUM:

CHK'D BY:

DWN BY:



-

PROJECT NO.:

REV NO.:



TITLE:

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UTM Zone 10

NAD 83

KS

BB


KX052806

1:4,000

0 50 100 150 20025m

$






1:45,000




FINAL

DRAFT


3002+000 3002+2003002+400

3002+6003002+800

3003+000

3003+2

00

3003+4

00

LIMIT OF CONSTRUCTION

STA. 3003+320.000

#*!A !A

!A

")") ")

")

")

")

")

")

")

")

!A!A

To Fo

rtSt.

John

Highw

ay29

TH18-A-019 TH18-A-020

TH18-A-021

TH17-A-009 TH17-A-010

TP17-A-016 TP17-A-017

CPT17-A-005

TH17-A-011

TP17-A-019TP17-A-020

TP17-A-023TP17-A-025

TP17-A-027

TP17-A-030

TP17-A-033

TP17-A-034

East AbutmentSta. 3002+060CL

1 2 3

SCALE:

PROJECTION:

DATUM:

CHK'D BY:

DWN BY:



-

PROJECT NO.:

REV NO.:



TITLE:

PROJECT:

UTM Zone 10

NAD 83

KS

BB


KX052806

1:4,000

0 50 100 150 20025m

$






1:45,000




FINAL

DRAFT

") ")")

")

")

")

")

")

")

")

")

")

")

")

")

") ")

")

")")

")

")

")

")

")

")

")

H a l f w a y R i v e r

P e a c e R i v e r

Highway29

PV17-001 PV17-002PV17-003

PV17-004PV17-005

PV17-006PV17-007

PV17-008PV17-009

PV17-010 PV17-011PV17-012

PV17-013PV17-014

PV17-015PV17-016 PV17-017

PV17-018PV17-019 PV17-020 PV17-021

PV17-022

PV17-023

PV17-024

PV17-025

PV17-026

PV17-027

SCALE:

PROJECTION:

DATUM:

CHK'D BY:

DWN BY:


CLIENT: DATE:

-

PROJECT NO.:

REV NO.:

SITE PLANASPHALT PAVEMENT CORING


TITLE:

PROJECT:

UTM Zone 10

NAD 83

KS

BB

S:\Internal\KX052806-HalfwayRiver-GIS\HR-AlignGeotechInv-Det-Fig3-SitePlan-AsphaltPaveCor.mxd

KX052806

1:10,000

0 200 400 600 800100m

$

Legend") Pavement Core Location

FIGURE 3Note: Image provided by Bing Maps Aerial - © 2017 DigitalGlobe Image courtesy of USGS © 2017 GeoEye © Province of British Columbia Earthstar Geographics SIO © 2017 Microsoft Corporation.



JUNE 2019BC HYDRO c/o R.F. BINNIE & ASSOCIATES LTD.

FINAL

DRAFT

2999+700 2999+800

Elevation (m

)

470

480

490

500

2999+600

Station (m)

Elevation (m

)

470

480

490

500

END

0.2

3.7

TS

GP145

4

TP17-A-001W

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 2999+600 TO 2999+860

GEOTECHNICAL INVESTIGATION

PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


Legend

L3000A20 Centerline Alignment Profile

Existing Ground Profile at Centreline

FIGURE 4

SHEET NO. 1 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20





Note: L3000A20 centreline alignment profile and existing ground profile at centreline

provided by R.F. Binnie & Associates Ltd. CAD file 'ALIGEOMPROF-16-0091.dwg',

received 31 March 2019.

FINAL

DRAFT

2999+900 3000+000 3000+100

470

480

490

500

460

Elevation (m

)

Station (m)

470

480

490

500

460

Elevation (m

)

END

0.2

3.7

TS18

5

TP17-A-002W

END

0.1

4.14/25/2017

TS

GP4

344

TP17-A-003W

END

0.1

3.74/25/2017

TS

GP4

77

TP17-A-004W

END

0.12.12.2

TSGP-GM

BR67

TP17-A-005W

END0.20.61.21.3

TS

SPBR

2610

TP17-A-006W

END

0.20.6

3

TSML

BR17 1731

16

14

TP17-A-007LLPLWSM3

GM2

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 2999+860 TO 3000+200


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


Legend



FIGURE 4

SHEET NO. 2 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20








FINAL

DRAFT

3000+200 3000+300 3000+400 3000+500

470

480

460

Elevation (m

)

450

440

430

Station (m)

470

480

460

450

440

430

Elevation (m

)

END

0.11.52.4

45.7

TS

GP-GM

BR

1550

10099RRR

41239628

161212

TH17-A-001N W0.1

3.4

TS

GP8677

TP17-A-008W

END

0.21.82.4

TSGP-GM 14

TP17-A-009W

END

0.21.2

2

TSGP

BR5

TP17-A-010W

SM2END

END

0.21.21.72.8

TSGM3

SP BR

TP18-A-035

N/A / N/AN/A / N/AN/A / N/A

N/A / N/A

0.02 / 0.39

0.35 / 0.36

0.04 / 0.08

N/A / N/A

N/A / N/A

N/A / N/A

0.58 / 0.48

0.42 / 0.30

0.56 / 0.59

0.41 / 0.47

N/A / N/A

0.48 / 0.41

0.65 / 0.53

0.12 / 0.35

0.36 / 0.43

0.59 / 0.73

0.47 / 0.26

0.66 / N/A

0.58 / 0.60

0.44 / 0.50

0.51 / 0.53

N/A / 0.27

0.52 / 0.49

0.58 / 0.66

N/A / N/A

Dia./ Axial

Is50

BR

(MPa)

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3000+200 TO 3000+540


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


Legend

Corrected Point Load Index (MPa)



FIGURE 4

SHEET NO. 3 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20




Is50BC HYDRO c/o R.F. BINNIE & ASSOCIATES LTD.




FINAL

DRAFT

3000+600 3000+700 3000+800

470

480

460

Elevation (m

)

450

440

430

Station (m)

470

480

460

Elevation (m

)

450

440

430

END

0.20.6

9

TSML

BR

46 17

TH18-A-022N W

END

0.10.5

45.7

TS

BR

359

210R175R

2147

1312

TH17-A-002N W

END

0.10.5

15.2

TSML

BR

541

121

271512

18 32

TH17-A-003N W PL LLEND

0.21.82.1

TS

BR

1218

TP17-A-011W

SM2- SM2GM2

TP17-A-012

END0.41.2

TSBR

TS

GP-GM

BR

END

0.6

3.3

45.7

1414373764R

TH17-A-004N

TSML

SM3

BR

END

0.10.61.1

10.6

262541

N

TH18-A-023

TP18-A-036

END

0.20.82.7

TS

BR23131111

WSM3

N/A / N/AN/A / N/A

0.30 / 1.65

0.35 / 1.66

N/A / N/A

0.24 / 1.13

0.12 / 1.16

0.07 / 1.22

0.09 / 0.63

0.13 / 0.99

0.16 / 0.93

0.05 / 0.91

0.10 / 1.12

0.25 / 1.22

0.16 / 0.64

0.14 / 0.48

0.25 / 1.31

0.04 / 0.58

0.31 / 1.57

0.25 / 1.02

0.09 / 1.18

0.28 / 0.50

0.21 / 0.61

0.12 / 0.94

0.17 / 0.60

0.14 / 1.55

0.23 / 1.68

0.31 / 0.87

0.45 / 1.96

Dia./ Axial

N/A / N/A

N/A / N/A

N/A / N/A

0.40 / 1.54

0.10 / 0.88

0.06 / 0.95

0.39 / 1.74

0.39 / 0.94

0.28 / 0.81

Dia./ Axial N/A / N/A

0.17 / 0.67

0.12 / 0.58

0.55 / 0.65

0.69 / 0.61

0.49 / 0.38

1.32 / 0.53

0.66 / 0.51

0.56 / 0.56

0.57 / 0.52

0.85 / 0.78

0.58 / 0.44

0.56 / 0.59

0.71 / 0.54

0.56 / 0.48

0.56 / 0.53

0.71 / 0.55

1.11 / 0.82

0.90 / 0.97

0.69 / 0.70

0.88 / 0.82

0.70 / 0.79

0.69 / 0.46

0.81 / 0.57

0.63 / 0.67

0.66 / 0.69

N/A / N/A

N/A / N/AN/A / N/A

N/A / N/A

N/A / N/A

0.36 / 0.38

0.66 / 0.60

Dia./ Axial

N/A / N/A

0.32 / 0.27

0.08 / 0.24

0.11 / 0.39

0.03 / N/A

0.33 / 0.40

Dia./ Axial

Is50

Is50

Is50

Is50

W

W(MPa)

(MPa)

(MPa)

(MPa)

2013

8167

14

Dia./ Axial

Is50 (MPa)

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3000+540 TO 3000+880


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


FIGURE 4

SHEET NO. 4 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20




Legend








FINAL

DRAFT

420

430

440

460

470

480

3000+900 3001+000 3001+100 3001+200

Elevation (m

)

Station (m)

490

420

430

440

450

460

470

480

Elevation (m

)

490

H A L F W A Y R I V E R

BRIDGE

450

END0.30.91.5

TS

BR49

TP17-A-013W

GM1

TS

BR

END

2/13/2018

0.11.8

25.8

TH18-A-024

BR

END

0.2

16.3

RR

TH18-A-025N

TSML

GP-GM

BR

END

2/17/2018

0.1

2.7

6.4

8.5

21.1

164729149348134

77R

TH18-A-027N

GP-GM

ML

END

2/8/2018

0.1

3.4

6.9

18

TS

GP-GM

BR

223582647111925

TH18-A-012N

END

2/22/2018

0.11

2.1

9.5

21.2

TSSP-SM

GP-GM

BR

2231010202121152843161926R

TH18-A-013N

SM3

END

0.1

3.2

50.3

TS

BR

1621277225RR

TH17-A-005N 50000

25000 800

2

400

qt(kPa) fs

(kPa)

CPT17-A-001

Refusal

END

0.10.32.4

45.7

TSGP-GM

BR

32R

TH18-A-026N

SM1 GM1

N/A / N/AN/A / N/A

0.41 / 0.27

0.27 / 0.20

0.32 / 0.39

0.33 / 0.36

0.44 / 0.31

0.26 / 0.17

0.31 / 0.25

0.24 / 0.37

0.35 / 0.24

Dia./ Axial

N/A / 0.24

0.03 / 0.40

0.07 / 0.63

0.31 / 0.37

0.27 / 0.43

0.28 / 0.47

0.37 / 0.45

0.07 / 0.33

0.45 / 0.49

0.24 / 0.39

0.30 / 0.36

0.50 / 0.31

0.12 / 0.55

0.03 / 0.31

0.27 / 0.48

0.21 / 0.54

0.62 / 0.48

0.52 / 0.43

0.45 / 0.56

0.05 / 0.40

0.31 / 0.14

0.01 / 0.49

0.06 / 0.43

0.05 / 0.29

0.29 / 0.45

0.16 / 0.37

0.08 / 0.63

0.25 / 0.28

Dia./ Axial

N/A / N/A

N/A / N/A

0.89 / 1.18

N/A / N/A

0.48 / 0.41

0.49 / 0.46

0.31 / 0.48

0.68 / 0.50

1.04 / 0.56

0.66 / 0.43

0.44 / 0.36

0.73 / 0.44

0.64 / 0.65

N/A / N/A

0.64 / 0.53

0.46 / 0.53

0.58 / 0.41

0.52 / 0.40

0.64 / 0.54

1.00 / 0.66

0.91 / 0.96

0.83 / 0.68

N/A / N/A

0.80 / 0.82

0.69 / 0.65

0.75 / 0.82

0.82 / 0.61N/A / N/AN/A / N/AN/A / N/A

0.94 / 1.11

1.07 / 0.94

Dia./ Axial

N/A / N/A0.05 / N/AN/A / N/A0.18 / 0.460.04 / N/A0.09 / 0.330.43 / 0.430.15 / 0.36

0.20 / 0.81

0.25 / 0.42

0.02 / 0.77

0.06 / 0.52

(MPa)

N/A / 0.340.22 / 0.32

0.03 / 0.37

0.02 / 0.34

0.07 / 0.43

0.02 / 0.35

0.02 / 0.41

0.28 / 0.67

Dia./ Axial

0.38 / 0.430.35 / 0.25

0.20 / 0.58

0.07 / 0.43

0.12 / 0.49

0.16 / 0.39

0.49 / 0.52

0.47 / 0.51

Dia./ Axial

21 2137 22

447

16N/A / N/A

N/A / N/A

0.21 / 0.28

0.17 / 0.28

0.56 / 0.35

0.28 / 0.40

0.30 / 0.89

0.37 / 0.53

0.13 / 0.42

0.15 / 0.47

0.22 / 0.47

0.06 / 0.29

0.34 / 0.57

0.34 / 0.55

0.44 / 0.52

0.03 / 0.43

Is50

Is50 Is50

Is50 Is50 Is50

W W

SM4

W W WSM4

(MPa)

(MPa) (MPa)

(MPa)(MPa)

11

2298

6415826791416

58112425

14127231289

1533334

PLLLDia./ Axial

4419

30 16 20

NIs50 WPLLL(MPa)

Dia./ Axial

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3000+880 TO 3001+220


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


FIGURE 4

SHEET NO. 5 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20




Legend








FINAL

DRAFT

3001+300 3001+400 3001+500

420

430

440

450

460

470

480

490

410

Elevation (m

)

Station (m)

420

430

440

450

460

470

480

490

410

Elevation (m

)


BRIDGE

END

0.2

2.3

8.5

30.5

TS

GP-GM

BR

35489

253923RRRR

TH17-A-006N

END

5/1/20170.61.41.8

7

30.5

SP

GP-GM

BR

7461435755110

48RRR

TH17-A-007N

END

1/25/2018

0.10.9

7.5

21.4

TS ML

GP-GM

BR

24254465532026482026

TH18-A-014N

END

2/25/2018

0.10.3

7.9

19.7

TS

GP-GM

BR

136234143

51R113725R49

70R

TH18-A-015N

END

1/31/2018

0.10.8

6.6

16.9

TS

GP-GM

BR

8373719343846R57

TH18-A-016N

SM3

SM1SM2

SM2GM2

5000025000 800

2

4

6

400

qt(kPa) fs

(kPa)

CPT17-A-002

Refusal8

5000025000 800

2

4

6

400

qt(kPa) fs

(kPa)

CPT17-A-003

RefusalN/A / N/A

0.47 / 0.470.40 / 0.55

0.41 / 0.46

0.81 / 0.52

0.54 / 0.49

0.58 / 0.38

N/A / N/A

0.62 / 0.71

0.54 / 0.46

N/A / N/A

0.58 / 0.45

0.49 / 0.51

0.42 / 0.56

0.48 / 0.66

Dia./ Axial

0.06 / 0.43

0.41 / 0.30

0.18 / 0.44

0.12 / 0.45

0.26 / 0.25

N/A / N/A

0.46 / 0.49

0.11 / 0.59

0.07 / 0.37

Dia./ Axial

N/A / N/AN/A / N/AN/A / N/A

N/A / N/A

0.67 / 0.49

0.58 / 0.52

0.58 / 0.44

0.66 / 0.65

N/A / N/A

0.52 / 0.73

0.07 / 0.69

0.51 / 0.71

0.39 / 0.66

N/A / N/A

N/A / N/A

0.57 / 0.27

Dia./ Axial

0.42 / 0.230.48 / 0.47

0.23 / 0.33

0.10 / 0.46

0.03 / 0.49

0.03 / 0.35

0.34 / 0.52

Dia./ Axial

Dia./ Axial

0.22 / 0.250.32 / 0.39

0.58 / 0.34

0.30 / 0.43

0.22 / 0.31

0.17 / 0.30

0.25 / 0.41

0.35 / 0.41

Is50Is50 Is50

Is50 Is50

5/24/2017 5/25/2017

WW

WW

(MPa)

(MPa) (MPa)

(MPa) (MPa)

W

276101751559816

27545

15797877

39

12118

2213

PL LL

13 29 17

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3001+220 TO 3001+560


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


FIGURE 4

SHEET NO. 6 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20




Legend








FINAL

DRAFT

3001+600 3001+700 3001+800 3001+900

420

430

440

450

460

470

480

490

410

Elevation (m

)

Station (m)

420

430

440

450

460

470

480

490

410

Elevation (m

)


BRIDGE

END

5/4/2017

0.6

7.7

30.6

TS

GP-GM

BR

4134225286029

67

38

RR

TH17-A-008N

END

1/24/2018

0.9

9.9

21.3

SP

GP-GM

BR

11242527R332924363219191314

TH18-A-017N

1/20/2018

0.10.6

8.9

19.6

TSML

GP-GM

BR

12163142206611465739413722R

TH18-A-018N

END

1/29/2018

0.21.5

5.55.9

16.8

TS

GP-GM

BR

17202334242522109R

TH18-A-019N

END

1/27/2018

3.5

14.9

GP

BR

68129R

TH18-A-020N

END

SM4

5000025000 800

2

4

6

400

qt(kPa) fs

(kPa)

CPT17-A-004

Refusal

8

0.17 / 0.400.28 / 0.33

0.15 / 0.73

0.18 / 0.31

0.31 / 0.26

0.10 / 0.33

0.58 / 0.66

0.30 / 0.72

Dia./ Axial

0.41 / 0.59N/A / N/A

0.30 / 0.63

N/A / N/A

0.20 / 0.48

0.09 / 0.52

0.25 / 0.42

Dia./ Axial

0.42 / 0.18

0.73 / 0.81

0.72 / 0.63

N/A / N/A

0.51 / 0.47

0.79 / 0.60

0.71 / 0.77

0.55 / 0.75

0.64 / 0.71

0.59 / 0.75

0.66 / 0.71

0.98 / 0.66

0.54 / 0.74

0.67 / 1.01

0.73 / 0.86

Dia./ Axial

0.27 / 0.34

0.30 / 0.38

0.05 / 0.50

0.41 / 0.62

0.40 / 0.45

0.60 / 0.45

0.74 / 0.36

Dia./ Axial

0.11 / 0.150.42 / 0.31

0.37 / 0.72

0.47 / 0.58

0.35 / 0.64

0.29 / 0.87

0.48 / 0.57

0.25 / 0.69

Dia./ Axial

17 33

Is50 Is50 Is50Is50

Is505/26/2017

W W WW

W

SP

(MPa) (MPa) (MPa)(MPa)

(MPa)

PL LL

21

243236

2521222

522877

7

89109

3647

7

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3001+560 TO 3001+900


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


FIGURE 4

SHEET NO. 7 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20




Legend








FINAL

DRAFT

3001+900 3002+000 3002+100 3002+200

430

440

450

460

470

480

Elevation (m

)

Station (m)

430

440

450

460

470

480

Elevation (m

)


BRIDGE

420 420

410 410

END

6/23/2017

0.2

14.415.1

TS

GP-GM

BR

562527974050364433R

157R88R373934

129RR2724RR

161111416002120230541010

2020

3232

TH17-A-010N W PL LL

END

0.20.4

4.4

TSML-

GP-GM

21 29272510552

TP17-A-017LLPLW

SM4

END

0.2

4.4

TS

GP75232

W

4.1

50.2

GP

BR

194133344734RR

TH17-A-009N

END

1/14/2018

0.10.4

16.6

62.3

TSGM3

GP-GM

BR

37

51

32

67

28

73

26

N

END

5000025000 800

2

4

400

qt(kPa) fs

(kPa)

CPT17-A-005

Refusal

TH18-A-021

TP17-A-016

0.24 / 0.48N/A / 0.45N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / 0.48

0.60 / 0.60

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

N/A / N/A

0.64 / 0.12

0.46 / 0.50

0.54 / 0.11

0.62 / 0.49

N/A / N/A

N/A / N/A

0.69 / 0.84

0.69 / 0.83

N/A / N/A

Dia./ Axial

0.62 / 0.780.44 / 0.62

0.24 / 0.63

0.43 / 0.92

0.81 / 0.69

0.32 / 0.70

0.25 / 0.47

0.44 / 0.70

0.45 / 0.45

0.28 / 0.74

0.52 / 0.73

0.42 / 0.85

0.46 / 0.14

0.31 / 0.34

0.59 / 0.55

0.52 / 0.84

0.52 / 0.84

0.43 / 0.68

0.43 / 0.50

0.17 / 0.40

0.53 / 0.46

0.41 / 0.37

0.31 / 0.39

0.27 / 0.50

0.48 / 0.45

0.42 / 0.80

0.37 / 0.49

0.19 / 0.54

0.24 / 0.43

N/A / N/A

Dia./ Axial

Is50

Is50

W

W

(MPa)

(MPa)

465365

101

2

2

2

3

7

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3001+900 TO 3002+240


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


FIGURE 4

SHEET NO. 8 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20




Legend








FINAL

DRAFT

3002+300 3002+400 3002+500

450

460

470

480

Elevation (m

)

490

Station (m)

450

460

470

480

Elevation (m

)

490

TH17-A-011N W PL LL

END

0.6

11.913.6

TS

GP-GM

BR

143124546612726

57

49

22

R

R

8110220

0

0

0

0

10

10

18

18

35

35

END

0.30.4

3.5

TS

GP264231

TP17-A-020W

ML-SM4

TP17-A-019

END

0.20.3

3

TSML-

SM4 GP35932

W

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3002+240 TO 3002+580


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


Legend



FIGURE 4

SHEET NO. 9 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20








FINAL

DRAFT

3002+700 3002+8003002+600

Elevation (m

)

460

470

480

490

Station (m)

Elevation (m

)

460

470

480

490

3002+900

END

0.20.3

4.5

TS

GP

11

6422

TP17-A-023W

END

0.20.31.3

4.5

TSCL-CH

GP

26 5034271542322

TP17-A-025LLPLW

END

0.20.81.3

4.5

TSCH

GP-GM

23 542572522

TP17-A-027LLPLW

SM2

SM1-GM1ML-SM4

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3002+580 TO 3002+920


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


Legend



FIGURE 4

SHEET NO. 10 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20








FINAL

DRAFT

3003+000 3003+100 3003+200

Elevation (m

)

460

470

480

490

Station (m)

Elevation (m

)

460

470

480

490

END

0.30.4

3.5

TSCH

GP-GM246

35

TP17-A-030W

END

0.30.8

3.4

TSCH

25 58261233

TP17-A-033LLPLW

GM1

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3002+920 TO 3003+260


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


Legend



FIGURE 4

SHEET NO. 11 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20








FINAL

DRAFT

3003+300 3003+400

Elevation (m

)

460

470

480

490

500

Station (m)

3003+500 3003+600

Elevation (m

)

460

470

480

490

500

END

0.1

3.9

GP62

22

TP17-A-034W

TS

N/A

PROJECTION:

N/A

DATUM:

PROFILES

STATION 3003+260 TO 3003+434.37


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX052806

-

CLIENT:

DWN BY:

CHK'D BY:

JUNE 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

HALFWAY RIVER


Legend



FIGURE 4

SHEET NO. 12 of 12

H 1 : 1000

V 1 : 500

0m 10 20 30 40

0m 5 10 15 20








FINAL

DRAFT

Appendix B

Slope Stability Outputs

FINAL

DRAFT

4/23/2019

Section 3000+750

Name: Case 1_Failure towards Peace River_Maximum Normal Reservoir Level_Do Nothing

1:750

1.36

-15 5 25 45 65 85450

460

470

480

KX052806Highway 29. HalfwayDate: 4/23/2019Last Edited By: Sinclair, KimFile Name: Section 3000+750.gszName: Case 1_Failure towards Peace River_Maximum Normal Reservoir Level_Do Nothing

Color Name Model Unit Weight(kN/m³)

Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)

1. Fill Mohr-Coulomb 21 0 36 1

2. Sand & Gravel

Mohr-Coulomb 21 0 37 1

3. Weathered Bedrock

Mohr-Coulomb 24.5 0 30 1

4. Shale Bedrock

Anisotropic Strength 24 1 75 75 35 45

6. Silt Mohr-Coulomb 19 0 26 1

FINAL

DRAFT

4/23/2019

Section 3000+750

Name: Case 1A_Failure towards Peace River_Maximum Normal Reservoir Level_Dig&Replace

1:750

1.54

-15 5 25 45 65 85450

460

470

480

KX052806Highway 29. HalfwayDate: 4/23/2019Last Edited By: Sinclair, KimFile Name: Section 3000+750.gszName: Case 1A_Failure towards Peace River_Maximum Normal Reservoir Level_Dig&Replace


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)


2. Sand & Gravel




4. Shale Bedrock



FINAL

DRAFT

4/23/2019

Section 3000+750

Name: Case 2A_Failure towards Peace River_Rapid Drawdown_Dig&Replace/Shear Key

1:750

1.46

-15 5 25 45 65 85450

460

470

480

KX052806Highway 29. HalfwayDate: 4/23/2019Last Edited By: Sinclair, KimFile Name: Section 3000+750.gszName: Case 2A_Failure towards Peace River_Rapid Drawdown_Dig&Replace/Shear Key


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)


2. Sand & Gravel




4. Shale Bedrock



FINAL

DRAFT

4/22/2019

Section 3000+830

Name: Case 1_Failure towards Peace River_MNRL__Do nothing

1:750

1.20

-20 -10 0 10 20 30 40 50 60 70 80 90

Ele

vation

445

455

465

475

445

455

465

475

KX052806Highway 29. HalfwayDate: 4/22/2019Last Edited By: Sinclair, KimFile Name: Section 3000+830.gszName: Case 1_Failure towards Peace River_MNRL__Do nothing


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)


2. Sand & Gravel




4. Shale

Bedrock



Weak Shale Mohr-Coulomb 24 0 16 1

FINAL

DRAFT

4/22/2019

Section 3000+830

Name: Case 1A_Failure towards Peace River_MNRL__Dig Replace/Shear Key)

1:750

1.54

-20 -10 0 10 20 30 40 50 60 70 80 90

Ele

vation

445

455

465

475

445

455

465

475

KX052806Highway 29. HalfwayDate: 4/22/2019Last Edited By: Sinclair, KimFile Name: Section 3000+830.gszName: Case 1A_Failure towards Peace River_MNRL__Dig Replace/Shear Key)


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)


2. Sand & Gravel




4. Shale

Bedrock




FINAL

DRAFT

4/22/2019

Section 3000+830

Name: Case 2A_Failure towards Peace River_Rapid Drawdown__Dig Replace/Shear Key)

1:750

1.43

-20 -10 0 10 20 30 40 50 60 70 80 90

Ele

vation

445

455

465

475

445

455

465

475

KX052806Highway 29. HalfwayDate: 4/22/2019Last Edited By: Sinclair, KimFile Name: Section 3000+830.gszName: Case 2A_Failure towards Peace River_Rapid Drawdown__Dig Replace/Shear Key)


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)


2. Sand & Gravel




4. Shale

Bedrock




FINAL

DRAFT

4/23/2019

Section 3000+899

Name: Case 1_Failure towards Peace River_Maximum Normal Reservoir Level (Entry Exit)_Do Nothing

1:1,050

1.35

-20 0 20 40 60 80 100 120 140445

455

465

475

485

KX052806Highway 29. HalfwayDate: 4/23/2019Last Edited By: Sinclair, KimFile Name: Section 3000+899.gszName: Case 1_Failure towards Peace River_Maximum Normal Reservoir Level (Entry Exit)_Do Nothing

Color Name Model Unit

Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand & Gravel




4. Shale Bedrock


5. Weak Shale



FINAL

DRAFT

4/23/2019

Section 3000+899

Name: Case 1A_Failure towards Peace River_Maximum Normal Reservoir Level (Dig Replace) (Entry Exit)

1:1,050

1.54

-20 0 20 40 60 80 100 120 140445

455

465

475

485

KX052806Highway 29. HalfwayDate: 4/23/2019Last Edited By: Sinclair, KimFile Name: Section 3000+899.gszName: Case 1A_Failure towards Peace River_Maximum Normal Reservoir Level (Dig Replace) (Entry Exit)


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand & Gravel




4. Shale Bedrock


5. Weak Shale



FINAL

DRAFT

4/23/2019

Section 3000+899

Name: Case 2A_Failure towards Peace River_Rapid Drawdown (Entry Exit)_Bench&Shear Key

1:1,050

1.44

-20 0 20 40 60 80 100 120 140445

455

465

475

485

KX052806Highway 29. HalfwayDate: 4/23/2019Last Edited By: Sinclair, KimFile Name: Section 3000+899.gszName: Case 2A_Failure towards Peace River_Rapid Drawdown (Entry Exit)_Bench&Shear Key


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand & Gravel




4. Shale Bedrock


5. Weak Shale



FINAL

DRAFT

5/22/2019

Section 3000+940

Name: Case 1_Failure towards Peace River_Maximum Normal Reservoir Level (Entry Exit)_Do Nothing

1:1,050

1.38

-20 0 20 40 60 80445

455

465

475

485

KX052806Highway 29. HalfwayDate: 5/22/2019Last Edited By: Sinclair, KimFile Name: Section 3000+940.gszName: Case 1_Failure towards Peace River_Maximum Normal Reservoir Level (Entry Exit)_Do Nothing


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand & Gravel




4. Shale Bedrock


5. Weak Shale Mohr-Coulomb 24 0 16 1


FINAL

DRAFT

5/22/2019

Section 3000+940

Name: Case 1A_Failure towards Peace River_Maximum Normal Reservoir Level (Dig Replace) (Entry Exit)

1:1,050

1.54

-20 0 20 40 60 80445

455

465

475

485

KX052806Highway 29. HalfwayDate: 5/22/2019Last Edited By: Sinclair, KimFile Name: Section 3000+940.gszName: Case 1A_Failure towards Peace River_Maximum Normal Reservoir Level (Dig Replace) (Entry Exit)


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand & Gravel




4. Shale Bedrock




FINAL

DRAFT

5/22/2019

Section 3000+940

Name: Case 2A_Failure towards Peace River_Rapid Drawdown (Entry Exit)_Bench&Shear Key

1:1,050

1.40

-20 0 20 40 60 80445

455

465

475

485

KX052806Highway 29. HalfwayDate: 5/22/2019Last Edited By: Sinclair, KimFile Name: Section 3000+940.gszName: Case 2A_Failure towards Peace River_Rapid Drawdown (Entry Exit)_Bench&Shear Key


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand & Gravel




4. Shale Bedrock




FINAL

DRAFT

6/14/2019

Section 3000+940

Name: Failure towards Peace River_MNRL (Dig Replace) (Entry Exit)_RipRap_Stability (1.75)

1:850

1.54

-20 0 20 40 60 80

Ele

va

tio

n

445

455

465

475

485

445

455

465

475

485

KX052806Highway 29. Halfway

Date: 6/14/2019Last Edited By: Sinclair, KimFile Name: Section 3000+940riprap.gsz

Name: Failure towards Peace River_MNRL (Dig Replace) (Entry Exit)_RipRap_Stability (1.75)


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)


2. Sand & Gravel




4. Shale Bedrock


5. Weak Shale



7. Rip Rap Mohr-Coulomb 26.6 0 45 1

FINAL

DRAFT

6/14/2019

Section 3000+940

Name: Failure towards Peace River_Maximum Normal Reservoir Level (Dig Replace) (Entry Exit)_RipRap (2H:1V)

1:1,050

1.55

-20 0 20 40 60 80445

455

465

475

485

KX052806Highway 29. HalfwayDate: 6/14/2019Last Edited By: Sinclair, KimFile Name: 3000+940riprap2H1V.gszName: Failure towards Peace River_Maximum Normal Reservoir Level (Dig Replace) (Entry Exit)_RipRap (2H:1V)


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand & Gravel




4. Shale Bedrock


5. Weak Shale



7. Rip Rap Mohr-Coulomb 26.6 0 45 1

FINAL

DRAFT

6/17/2019

Section 3000+900

Name: Case 6_Failure towards Halfway River_Existing Conditions_Sensitivity analysis

1:1,650

1.267

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140 160380

390

400

410

420

430

440

450

460

470

480

KX052806

Highway 29. Halfway

Section 3000.897

Date: 6/17/2019

Last Edited By: Sinclair, Kim

File Name: Section 3000+900.gsz

Name: Case 6_Failure towards Halfway River_Existing Conditions_Sensitivity analysis

Color Name Model Unit Weight (kN/m³)

Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)


2. Sand & Gravel Mohr-Coulomb 21 0 37 1

4. Shale Bedrock Anisotropic Strength 24 1 75 75 35 45


FINAL

DRAFT

13/03/2019

Section 3000+500

Name: Case 1A_Failure towards Halfway River_Maximum Normal Reservoir Level

1:1,400

1.70

-150 -130 -110 -90 -70 -50 -30 -10 10 30 50 70 90 110 130 150400

410

420

430

440

450

460

470

480

KX052806

Highway 29. Halfway

Date: 13/03/2019





Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





FINAL

DRAFT

13/03/2019

Section 3000+500

Name: Case 1B_Failure towards Halfway River_Rapid Drawdown_fully undrained

1:1,400

1.24

-150 -130 -110 -90 -70 -50 -30 -10 10 30 50 70 90 110 130 150400

410

420

430

440

450

460

470

480

KX052806

Highway 29. Halfway

Date: 13/03/2019



Name: Case 1B_Failure towards Halfway River_Rapid Drawdown_fully undrained


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





FINAL

DRAFT


1:1,382

1.53

-180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140400

410

420

430

440

450

460

470

480

Highway 29. Halfway

Section 3000.897

Date: 13/03/2019





Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





Section 3000+600

13/03/2019

FINAL

DRAFT

Name: Case 1D_Failure towards Halfway River_Rapid Drawdown_1 m partial drainage

1:1,382

1.15

410

420

430

440

450

460

470

480

Highway 29. Halfway

Section 3000.897

Date: 14/03/2019





Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





Section 3000+600

14/03/2019

400-180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140

FINAL

DRAFT

Name: Case 3A_Failure towards Halfway River_MNRL (shift highway south 4.5 m)

1:1,382

1.62

-180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140400

410

420

430

440

450

460

470

480

Highway 29. Halfway

Section 3000.897

Date: 13/03/2019



Name: Case 3A_Failure towards Halfway River_MNRL (shift highway south 4.5 m)


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





Section 3000+600

13/03/2019

FINAL

DRAFT

Name: Case 3B_Failure towards Halfway River_Rapid Drawdown (shift highway south 4.5 m) (1 m partial drawd

1:1,382

1.25

-180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140400

410

420

430

440

450

460

470

480

Highway 29. Halfway

Section 3000.897

Date: 13/03/2019



Name: Case 3B_Failure towards Halfway River_Rapid Drawdown (shift highway south 4.5 m) (1 m partial drawdown)


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





Section 3000+600

13/03/2019

FINAL

DRAFT

13/03/2019

Section 3000+700


1:1,400

1.55

-175 -155 -135 -115 -95 -75 -55 -35 -15 5 25 45 65 85 105 125 145395

405

415

425

435

445

455

465

475

485

495

KX052806

Highway 29. Halfway

Date: 13/03/2019





Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





FINAL

DRAFT

13/03/2019

Section 3000+700


1:1,400

1.17

-175 -155 -135 -115 -95 -75 -55 -35 -15 5 25 45 65 85 105 125 145395

405

415

425

435

445

455

465

475

485

495

KX052806

Highway 29. Halfway

Date: 13/03/2019





Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





FINAL

DRAFT

13/03/2019

Section 3000+700

Name: Case 3B_Failure towards Halfway River_Rapid Drawdown (Shift Highway to south 3 m)

1:1,400

1.24

-175 -155 -135 -115 -95 -75 -55 -35 -15 5 25 45 65 85 105 125 145395

405

415

425

435

445

455

465

475

485

495

KX052806

Highway 29. Halfway

Date: 13/03/2019



Name: Case 3B_Failure towards Halfway River_Rapid Drawdown (Shift Highway to south 3 m)


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





FINAL

DRAFT

14/03/2019

Section 3000+800


1:1,600

1.58

-175 -155 -135 -115 -95 -75 -55 -35 -15 5 25 45 65 85 105 125 145 165

Ele

vation

380

390

400

410

420

430

440

450

460

470

480

380

390

400

410

420

430

440

450

460

470

480

KX052806

Highway 29. Halfway

Date: 14/03/2019





Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





FINAL

DRAFT

14/03/2019

Section 3000+800

Name: Case 1D_Failure towards Halfway River_Rapid Drawdown (1m drawdown)

1:1,600

1.18

-175 -155 -135 -115 -95 -75 -55 -35 -15 5 25 45 65 85 105 125 145 165

Ele

vation

380

390

400

410

420

430

440

450

460

470

480

380

390

400

410

420

430

440

450

460

470

480

KX052806

Highway 29. Halfway

Date: 14/03/2019



Name: Case 1D_Failure towards Halfway River_Rapid Drawdown (1m drawdown)


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





FINAL

DRAFT

14/03/2019

Section 3000+800

Name: Case 3B_Rapid Drawdown _Shift alignment south_3m_1 m partial drainage

1:1,600

1.26

-175 -155 -135 -115 -95 -75 -55 -35 -15 5 25 45 65 85 105 125 145 165

Ele

vation

380

390

400

410

420

430

440

450

460

470

480

380

390

400

410

420

430

440

450

460

470

480

KX052806

Highway 29. Halfway

Date: 14/03/2019



Name: Case 3B_Rapid Drawdown _Shift alignment south_3m_1 m partial drainage


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





FINAL

DRAFT


1:1,650

1.63

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140 160380

390

400

410

420

430

440

450

460

470

480

KX052806

Highway 29. Halfway

Section 3000.897

Date: 14/03/2019





Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





Section 3000+900

14/03/2019

FINAL

DRAFT

Name: Case 1B_Failure towards Halfway River_Rapid Drawdown (Fully Undrained Case)

1:1,650

1.25

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140 160380

390

400

410

420

430

440

450

460

470

480

KX052806

Highway 29. Halfway

Section 3000.897

Date: 14/03/2019



Name: Case 1B_Failure towards Halfway River_Rapid Drawdown (Fully Undrained Case)


Cohesion'(kPa)

Phi' (°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)





Section 3000+900

14/03/2019

FINAL

DRAFT

2.183

-55 -35 -15 5 25 45 65 85 105 125 145 165 185 205 225 245 265421

426

431

436

441

446

451

456

461

466

471

476

481


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)

1. Embankment Fill (Sand and Gravel)


2. Sand and Gravel Mohr-Coulomb 20.5 0 35 1

3. Clay/Silt Effective Stress


4. Residual Soil/ Weathered Bedrock


5. Bedrock Anisotropic Strength 24.5 1 50 50 35 45

6. Weak Shale Mohr-Coulomb 24.5 0 16 1

KX052806Highway No. 29 Halfway Section 3002+300Date: 03/08/2018Last Edited By: Sinclair, KimName: Failure towards Peace River_ Rapid Drawdown

03/08/2018

Section 3002+300

Name: Failure towards Peace River_ Rapid Drawdown

1:1,382

FINAL

DRAFT

2.333

-55 -35 -15 5 25 45 65 85 105 125 145 165 185 205 225 245 265421

426

431

436

441

446

451

456

461

466

471

476

481


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)

1. Embankment Fill (Sand and Gravel)


2. Sand and Gravel Mohr-Coulomb 20.5 0 35 1



4. Residual Soil/ Weathered Bedrock




KX052806Highway No. 29 Halfway Section 3002+300Date: 03/08/2018Last Edited By: Sinclair, KimName: Failure towards Peace River_Maximum Normal Reservoir Level

03/08/2018

Section 3002+300

Name: Failure towards Peace River_Maximum Normal Reservoir Level

1:1,382

FINAL

DRAFT

03/08/2018

Section 3002+800

Failure towards Peace River_ Rapid Drawdown

1:1,382

2.306

-55 -35 -15 5 25 45 65 85 105 125 145 165 185 205 225 245 265421

426

431

436

441

446

451

456

461

466

471

476

481


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand and Gravel








KX052806Highway No. 29 Halfway Section 3002+300Date: 03/08/2018Last Edited By: Sinclair, KimName: Failure towards Peace River_ Rapid Drawdown

FINAL

DRAFT

03/08/2018

Section 3002+800

Failure towards Peace River_Maximum Normal Reservoir Level

1:1,382

2.481

-55 -35 -15 5 25 45 65 85 105 125 145 165 185 205 225 245 265421

426

431

436

441

446

451

456

461

466

471

476

481


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Sand and Gravel








KX052806Highway No. 29 Halfway Section 3002+300Date: 03/08/2018Last Edited By: Sinclair, KimName: Failure towards Peace River_Maximum Normal Reservoir Level

FINAL

DRAFT

Limitations

FINAL

DRAFT

GEOTECHNICAL ASSESSMENT AND DESIGN


Project # KX052806 | June 18, 2019

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

Limitations (optional)

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.

FINAL

DRAFT

Documents

GEOTECHNICAL ASSESSMENT AND DESIGN · Geotechnical Assessment and Design Halfway River Segment Project # KX052806 | 6/18/2019 Page 3 INTRODUCTION As part of BC Hydro’s proposed