geotechnical assessment and design · 2019-08-19 · geotechnical assessment and design bear flat...

Prepared for:

R.F. Binnie & Associates Ltd.

101 - 1577 7th Avenue, Prince George, BC, V2L 3P5

August 14, 2019

GEOTECHNICAL ASSESSMENT AND

DESIGN

Bear Flat Cache Creek Segment (East)

Highway 29, British Columbia

Project # KX05280503

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

GEOTECHNICAL ASSESSMENT AND DESIGN


Highway 29, British Columbia

Project # KX05280503

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

101 - 1577 7th Avenue, Prince George, BC, V2L 3P5

Prepared by: Wood Environment & Infrastructure Solutions,

a Division of Wood Canada Limited

3456 Opie Crescent Prince George, BC V2N 2P9

August 14, 2019

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Geotechnical Assessment and Design


Project # KX05280503 | 8/14/2019 Table of Contents

Table of Contents

INTRODUCTION ................................................................................................................................................................... 1

SCOPE ....................................................................................................................................................................................... 1

GENERAL PROJECT DESCRIPTION ................................................................................................................................ 2

BACKGROUND ...................................................................................................................................................................... 3

4.1 GEOLOGY ............................................................................................................................................................... 3

SITE CONDITIONS AND DISCUSSION ......................................................................................................................... 4

5.1 SUBSURFACE GEOLOGICAL CONDITIONS – HIGHWAY 29 REALIGNMENT ................................ 4

5.2 SHALE BEDROCK ................................................................................................................................................. 5

5.3 ACID ROCK DRAINAGE AND METAL LEACHING POTENTIAL ........................................................... 6

5.4 EXISTING HIGHWAY 29 ASPHALT THICKNESS ........................................................................................ 6

5.5 GROUNDWATER CONDITIONS ..................................................................................................................... 7

GEOTECHNICAL DESIGN CONSIDERATIONS & RECOMMENDATIONS ........................................................ 9

6.1 STRIPPING .............................................................................................................................................................. 9

6.2 SUBGRADE PREPARATION .............................................................................................................................. 9

6.3 TEMPORARY EXCAVATIONS .........................................................................................................................10

6.4 EMBANKMENT FILL CONSTRUCTION .......................................................................................................10

6.4.1 Embankment Fill East of Cache Creek (Station 407+450 to 408+880) .......................11

6.5 CUT SLOPES .........................................................................................................................................................15

6.6 GEOTEXTILE AND BIAXIAL GEOGRID SPECIFICATIONS .....................................................................16

6.7 PAVEMENT STRUCTURE .................................................................................................................................16

6.8 WASTE DISPOSAL .............................................................................................................................................17

6.9 INSTRUMENTATION ........................................................................................................................................18

6.9.1 New Instrumentation & Monitoring .........................................................................................18

6.9.2 Protection of Existing Instrumentation ....................................................................................19

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

CLOSURE ...............................................................................................................................................................................21

REFERENCES .........................................................................................................................................................................22

List of Appendices

APPENDIX A FIGURES

APPENDIX B SLOPE STABILITY ANALYSIS (SLOPE/W)



Project # KX05280503 | 8/14/2019 Table of Contents

List of Tables

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

Table 5-2: Measured Asphalt Core Thickness ........................................................................................................................... 6

Table 5-3: Summary of Groundwater Monitoring ................................................................................................................... 8

Table 6-1: Summary of Subsurface Conditions (Sta. 407+450 to 408+880) ............................................................. 12

Table 6-2: Geotechnical Material Properties for Limit Equilibrium Slope Stability Analyses............................... 13

Table 6-3: Summary of Limit Equilibrium Slope Stability Analyses for 3H:1V Embankment Fill Slopes ......... 14

Table 6-4: Non-Woven Geotextile Specifications ................................................................................................................. 16

Table 6-5: Biaxial Polypropylene Geogrid Specifications .................................................................................................. 16

Table 6-6: Recommended Minimum Pavement Structure Thickness ........................................................................... 16

Table 6-7: Detailed Geotechnical Recommendations by Station Section .................................................................. 20



Project # KX05280503 | 8/14/2019 Page 1

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

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

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

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

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

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

approximately 4.9 km long segment of Highway 29. The general location is shown in Figure 1, and a plan

of the proposed realignment is provided on two map sheets in Figure 2. This report has been prepared

specifically in relation to the approximately 1.8 km long easternmost portion of the alignment located on

the east side of the Cache Creek valley and proposed new bridge crossing.

Granular borrow investigations carried out in the vicinity of the Bear Flat Cache Creek realignment are

described in separate reporting. Additional background geotechnical information is provided in our

previous report: Preliminary Geotechnical Assessment, Proposed Bear Flat Segment, Highway 29 Definition

Design, Site C Clean Energy Project dated 5 March 2012. Results of geotechnical subsurface investigations

carried out to date are provided in our report: Geotechnical Data Report, Bear Flat Cache Creek Segment,

dated 14 August 2019. Amec Foster Wheeler also produced a Geotechnical Assessment and Design

Report: Geotechnical Assessment and Design, Highway No. 29, Bear Flat-Cache Creek, dated 21 July 2017,

for a previous L4000-Line alignment which has since been superseded.

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 on the east side of Cache Creek. The detailed design (analysis and

reporting) of the bridge structure, abutments/end fills and portion of the alignment to the west of Cache

Creek are reported separately.

SCOPE The general scope of Wood’s geotechnical field assessment for the Bear Flat Cache Creek realignment

segment was as described in Work Order 5 Release 3 Highway 29 Contract Completion for the Cache Creek

West (CCW) segment and the Detail and Functional Design of a new alignment called the Cache Creek East

(CCE) segment, and pursuant to the Sub-Consultant Agreement between Binnie and Wood, dated 1 April

2018.

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



Project # KX05280503 | 8/14/2019 Page 2

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

penetration testing and downhole geophysical testing subcontractors;

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,

Settlement due to embankment loading.

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

Compilation of this report.

GENERAL PROJECT DESCRIPTION The proposed 4.9 km long Bear Flat Cache Creek realignment segment is referenced as L4000O43 (Binnie

draft geometric design drawings dated 24 June 2019). The subject L4000O43 Line begins near Station

404+200 (eastern terminus of what is referred to as the Cache Creek West segment of the new Highway

29 alignment) and runs north of and approximately parallel to the existing Highway 29 alignment. The

new alignment will consist of two paved lanes. A major bridge structure is planned over Cache Creek

between approximately Sta. 406+744 to Sta. 407+334. The new highway alignment then merges with the

existing highway at approximately Station 409+144.

This report provides a discussion and preliminary geotechnical recommendations prepared by Wood for

the functional design of the approximately 1.8 km section of the proposed Bear Flat Cache Creek segment

on the east side of Cache Creek (i.e. from Sta. 407+334 to 409+144). Generally, the new highway

alignment is located north of the future Site C reservoir shoreline, along an upper fluvial terrace level

within the Peace River valley.

Figure 1 depicts the general location of the project segment. Figure 2 presents a detailed plan view of the

new highway alignment on an orthophoto underlay. Figure 3 (sheets 1 to 4) depicts a profile view along

the new highway alignment centreline.

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

project segment, the reader is referred to our definition design phase reporting (Amec Foster Wheeler, 5

March 2012). Results of geotechnical subsurface investigations carried out to date are provided in our

report: Geotechnical Data Report, Bear Flat Cache Creek Segment, dated 14 August 2019.



Project # KX05280503 | 8/14/2019 Page 3

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 Shaftsbury Formation (part of

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

Clague, 2008 and Bidwell, 1999). Gates Formation sandstone (also part of the Fort St. John group) can be

found underlying the Shaftesbury Formation (Thurber, 1978). The bedding inclination of 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 Dunvegan sandstone outcrops in upper elevation slopes within the Peace River Valley, within a

previously identified landslide feature (see Figure 2, Cache Creek Landslide). The contact between the

sandstone and the underlying shale is estimated to be near 670 m elevation (Thurber, 1978). 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 Bear Flat Cache Creek project segment, shale bedrock outcrops are apparent along both the

Peace River and the Cache Creek valley sidewall slopes between the base of the valley at about 430 m

elevation up to about 465 m elevation. Shale is assumed to underlie the terrace on which the alignment

will be constructed at shallow depth, and underlie the upper terrace at depths of 3 to 16 m.

The Gates Formation can consist of sandstone, shale and silty shale. It does not outcrop within the Bear

Flat project segment and is anticipated to underlie the valley bottom at an unknown depth.

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

research papers (Matthews, 1978; Hartman and Clague, 2008) identify and describe a series of

predecessor valleys of the Peace River and its tributaries. In general, four paleovalleys have been identified

within the proposed Site C reservoir area. The paleovalleys are sometimes wider, but generally shallower

than the modern valley. The valleys are infilled with a sediment sequence that can be listed by decreasing

age as follows: pre-glacial fluvial deposits overlying the bedrock; advance phase fine-grained

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

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

silt and landslide debris.

In the Bear Flat Cache Creek project segment, a predecessor of the modern Halfway River tributary

drainage meets the ancient Peace River valley. As a result, the Peace Valley sidewall slopes within the

project area west of Cache Creek are underlain by colluvium derived from glacial sediments. East of Cache

Creek valley, the slopes are primarily underlain by similar colluvium, but shale bedrock outcrops in existing

highway cuts on the lower reaches of Cache Creek Hill.



Project # KX05280503 | 8/14/2019 Page 4

SITE CONDITIONS AND DISCUSSION

5.1 SUBSURFACE GEOLOGICAL CONDITIONS – HIGHWAY 29

REALIGNMENT

Sta. 407+334 to 407+450: This section comprises the eastern approach to the planned new bridge

across the Cache Creek valley. Embankment sections up to 3.5 m high would be constructed on the

relatively level surface of a fluvial terrace. The subsurface conditions are anticipated to consist of up to 0.2

m of topsoil and 1.9 to 2.4 m high plastic clay and silt overlying 7.8 m to 9.6 m of compact to very dense

fluvial sand and gravel. Shale bedrock occurs under the sand and gravel, anticipated to be at an elevation

of approximately 462.6 m to 463.9 m along the alignment centerline.

Sta. 407+450 to 408+880: This section of the alignment comprises a significant embankment, ranging

up to 12 m in height, to be constructed adjacent to the existing Highway 29 alignment across terrain that

dips gently towards the south. Between approximately Sta. 407+900 and 408+340 the lower portions of

the highway embankment would be within the Site C reservoir. The south-sloping terrain appears to

represent a subdued colluvial fan consisting of fine-grained soils (likely derived from the adjacent Peace

River valley slopes to the north and east). The colluvial fan appears to overlie a remnant fluvial terrace

feature comprised of eroded shale bedrock, fluvial overbank and/or lacustrine soil deposits. Topsoil under

the embankment footprint is expected to range in thickness from 0.3 m to 0.5 m. Beneath the topsoil, the

foundation conditions for the embankment are expected to consist predominantly of firm to very stiff,

intermediate plasticity silty clay soils ranging in depth from 3 m to 10.7 m below ground surface. The silty

clay deposit thickness appeared to increase towards the north and east. Moisture contents were typically

at or below the plastic limit. The upper 4 m of silty clay appears to be over-consolidated, while at depth

the silty clay appeared to be normally to slightly over-consolidated. Weathered shale and/or shale

bedrock underlies the embankment area at variable depths (ranging from 3 m to greater than 25 m below

surface, at elevations between about 453 m and 466 m depending on location). Generally, the underlying

bedrock profile appeared to dip towards the south and west. In addition to the fine-grained soil and shale

bedrock, some isolated or discontinuous deposits of sand and gravel were noted to occur, typically

directly overlying the shale bedrock. Groundwater appears to be perched on some areas of bedrock and

may also be perched in the more permeable granular soil seams that directly overlie lower elevation

sections of the shale bedrock surface. Of note, at three locations north of Sta. 408+700 (drilling

encountered several meters of variably intact and/or distorted/broken shale within a sequence of

unconsolidated silt and clay soils. Within this section, between 3.1 and 7.9 m of the intervening shale

deposit was encountered at depths ranging from 8.2 m to 10.7 m below ground surface. It is postulated

that these shale deposits represent buried colluvium derived from the adjacent slope of the Peace River

valley, and possibly even distal portions of the landslide run-out debris from the adjacent historic Cache

Creek Slide area.

Sta. 408+880 to 409+143.892: Represents a transitional side slope fill area (up to 15 m in height) from

the low lying, gently sloping colluvial fan terrain described above, onto the existing Highway 29 fill

alignment along the lower reaches of the north slope of the Peace River valley, an area that is referred to

as Cache Creek Hill. Topsoil in the order of 0.3m in thickness is anticipated to occur on the native ground

and portions of the existing highway fill slope, although it may be deeper in some locations, particularly

along ditch bottoms. Foundation conditions for the new highway embankment are expected to consist of

a relatively thick sequence (up to at least 8.8 m) of low to medium plastic, stiff to very stiff silty clay and/or

highway embankment composed of similar material. Moisture contents for this fine-grained soil are

anticipated to be at or below the plastic limit. Intact shale bedrock is expected to be relatively deep, at

depths ranging from 13.1 to 14.5 m below ground surface (approximate elev. 498.9 m to 507 m),

depending on location. However, at two drill locations (BH16-A-034 and BH16-A-035) old landslide debris



Project # KX05280503 | 8/14/2019 Page 5

or colluvium was noted at depths of 7.9 m and 8.8 m under the existing highway alignment. Significant

groundwater was not encountered in this area. However, there may be local pockets of groundwater

seepage on side slope areas not specifically investigated.

5.2 SHALE BEDROCK

In general, 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). Although it is not expected that shale bedrock will be

encountered by the proposed new highway alignment earthworks east of Cache Creek, the shale bedrock

locations and elevations encountered by drilling relative to the L4000O43-Line (Station and Offsets) are

summarized in Table 5.1, below.

In general, at the interface between the overburden and shale bedrock, the shale was weak, highly

weathered and in many instances resembled residual clay soil. Based on previous experience in the area,

portions of the Shaftesbury shale can be highly sensitive to moisture changes when exposed/disturbed

and can rapidly decompose to a clay-like soil. The shale bedrock is generally not considered suitable for

highway embankment fill construction without special consideration (low slope angles, careful placement,

encapsulation to prevent moisture driven decomposition, etc.).

Table 5-1: Encountered Bedrock

ID Station Offset

(m)

Bedrock Depth

(m)

Bedrock Elevation

(m)

BH18-A-073 407+331 -12 9.9 463.4

BH18-A-077 407+393 -8 10.2 463.9

BH18-A-017 407+435 40 9.7 463.6

BH18-A-051 407+540 -16 11.7 462.6

BH18-A-078 407+677 2 10.2 461.9

BH18-A-020 407+803 3 4.9 463.4

TH16-A-055 407+896 -22 3.6 460.8

BH16-A-026 407+996 -43 4.2 458.8

TH16-A-056 408+002 -2 3 458.9

BH16-A-027 408+129 -4 4.5 455.3

BH16-A-029 408+258 -36 5.7 458.6

BH16-A-028 408+261 92 7 453.4

BH16-A-030 408+377 39 5.8 458.6

BH16-A-031 408+500 53 9 462.6

BH16-A-032 408+505 -21 7.5 466.3

BH16-A-033 408+617 42 15.9 466.2

TH16-A-061 408+859 16 7.3 498.8

BH16-A-035 408+944.1 9.5 7.9 504.6



Project # KX05280503 | 8/14/2019 Page 6

5.3 ACID ROCK DRAINAGE AND METAL LEACHING POTENTIAL

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

alignment. To assess the shale’s potential for acid rock drainage (ARD) and metal leaching (ML), two core

samples were selected from two drill holes completed near the western bridge abutment area (BH16-A-

015, at an approximate depth 7.6 m / elevation of 462 m and DH11-51, at approximate depth of 7.1 m /

elevation of 461.9 m). The samples were crushed and sent to SGS Canada Inc. (SGS) in Burnaby, BC for

acid-base accounting (ABA) analysis and multi-element analyses, and to SGS in Lakefield, Ontario for

quantitative X-ray diffraction by Rietveld Refinement. The laboratory results can be found in the

Geotechnical Data Report.

ABA results indicated that the pH values of the samples were 6.82 and 7.8 for BH16-A-015 and DH11-51,

respectively, with the total concentrations of sulphur at 0.52% and 0.48%. The acid potential (AP) values

(based on the sulphide content) were 11.3 and 12.2 tonnes CaCO3 per 1000 tonnes of material, and the

modified Sobek Neutralization Potential (NP) values were 3.4 and 32.7 tonnes CaCO3 per 1000 tonnes of

material respectively.

The neutralization potential ratio (NPR) is a measure of the proportion of NP to AP (NPR = NP/AP). The

NPR value for BH16-A-015 was 0.3, while for DH11-51 it was 2.68. Based on the NPR criteria outlined in

the guidance document Technical Circular Letter T-04/13 (MoTI, 15 September 2013), the sample from

BH16-A-15 was classified as having a high potential to produce ARD. The sample from DH11-15 was

classified as non-acid generating with low potential to produce ARD. While both samples contained pyrite

(1.2 to 1.3%), only DH11-51 had appreciable carbonate (calcite, siderite) which would provide offsetting

neutralization potential. This high variation between the two samples found in relatively close proximity

and at similar elevations suggests that the ARD & ML potential will most likely be highly variable and

dependent on local mineralogy within each shale layer. Accordingly, it will be onerous and likely

impractical to screen and separate non-acid generating layers from shale that is or has the potential to be

acid generating. Consequently, it is conservatively considered that all the shale bedrock, if encountered,

should be considered as potentially acid generating, and where excavated should be disposed of in an

environmentally appropriate manner. Should significant surface exposures of shale remain after

excavation, they could likely be appropriately treated by backfill cover as needed.

5.4 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 2 depicts the coring locations.

Table 5-2: Measured Asphalt Core Thickness

Hole ID Thickness

(mm) Hole ID

Thickness

(mm)

PV16-A-016 165 PV16-A-025 85

PV16-A-017 180 PV16-A-026 55

PV16-A-018 210 PV16-B-027 70

PV16-A-019 135 PV16-A-028 50

PV16-B-020 155 PV16-B-029 70

PV16-A-021 185 PV16-A-030 55

PV16-A-022 180 PV16-A-031 60

PV16-A-023 215 PV16-A-032 70

PV16-A-024 140 - -



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5.5 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 August 2019).



Project # KX05280503 | 7/2/2019 Page 8

Table 5-3: Summary of Groundwater Monitoring

Hole ID Station Offset Piezometer

No.

Elevation

Ground/Tip

(m)

Maximum

Measured

Piezometric

Level in 2016

Minimum

Measured

Piezometric

Level in 2016

Measured

Piezometric

Level in 2018

Measured

Piezometric

Level in 2019

BH16-A-025 407+412 269R

BH025A 461.3/436.3 439.9 445.5 445.5 445.5

BH025B 464.3/412.8 431.0 437.4 433.1 432.9

BH16-A-026 407+996 43L BH026 463.0 460.1 460.1 460.1 460.1

BH16-A-028 408+261 93R BH028 460.4/453.7 453.7 453.3 454.0 454.7

BH16-A-031 408+500 53R BH031B 471.6/467.3 469.6 468.5 468.8, 468.9 469.0

BH031A 471.6/462.8 470.7 470.5 470.7, 470.8 470.5

BH16-A-033 408+617 42R BH033A 482.1/473.6 475.9 475.8 476.7 476.5

BH033B 482.1/466.8 472.1 472.0 472.4 472.2



Project # KX05280503 | 8/14/2019 Page 9

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 the L4000O43 alignment

as proposed. Section 6.1 through Section 0 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 6.10. Recommendations are

based on specific base mapping data provided to Wood on 9 Jan 2018 and design alignment L4000O43

provided on 24 June 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 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, colluvial slopes 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 6.10, 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 6.10 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-

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.



Project # KX05280503 | 8/14/2019 Page 10

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

For the majority of the alignment, new embankment fills are estimated to be greater than 5 m high.

Maximum fill slopes of 3H:1V are recommended. This maximum slope recommendation of 3H:1V is also

based on the embankment being constructed on a properly prepared subgrade approved by a

geotechnical engineer, and the fill consisting primarily of clean granular fill for its upper and lower

portions. Note that a stabilization berm is required for higher fill areas between Sta. 407+450 to 408+880.

See Section 6.4.1 for more details.

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 SS 2016.

Existing organic materials, loose fill and/or otherwise unsuitable soils should be removed from under

the footprint of any new fills and from the outside face of the existing fill slopes prior to placing the

new fill.

Fill materials should consist of inorganic granular soil with moisture contents near (±1%) of the

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

conducive to good compaction. In general, the following two granular fill types are recommended for

indicated uses:

Clean Granular Fill (CGF) – to be used for all embankment/berm fills constructed below an elevation of

466 m, the lower or back 1 m of fills placed on or against groundwater seepage zones..

♦ Material is to be free of organics and other detritus and has less than 5 % passing the

0.075 mm sieve.

♦ Maximum particle size as large as 300 mm can be used, provided that adequate lift thickness

and compaction is achieved before placement of the next lift. The contractor must

demonstrate via test strips and test excavations that they have the equipment, methodology

and are achieving compaction nominally equivalent to 95 % (Standard Proctor Maximum Dry

Density as per the current version of ASTM D 698), with no observable segregation or

deflection and no rutting greater than 10 mm under construction traffic loading.

Type D Granular Fill (Type D) – to be used for all other fill locations, where internal drainage is not

required as described above.

♦ Material gradation shall meet SS 2016 Section 201.44 and consist of predominately granular

material with a maximum 300 mm particle size that contains a maximum of 20% fines

(material passing the 0.075 mm sieve), and is free of organics and other detritus material.



Project # KX05280503 | 8/14/2019 Page 11

Fills that will 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 and may need to be

treated by placement of a granular drainage blanket from the base of the excavation to a minimum of

2.0 m above the seepage area. Figure 5 Sheet 2 provides a typical construction detail for construction

of granular drainage blankets.

Fills underlain by groundwater seepage zones should be founded on a minimum 0.5 m thickness (as

measured above the high-water level or original ground surface, as determined by the geotechnical

engineer) of clean granular fill. A layer of non-woven geotextile (as defined in Section 6.6) should be

placed on the prepared subgrade before placement of granular drainage fill. Geotextile should also be

placed over granular drainage fill where finer-grained fill (i.e. having greater than 5% fines) will be

placed over the cleaner drainage fill.

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

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

without additional armouring and/or riprap.

At the transition sections between the new highway embankment and existing embankment, positive

subsurface drainage away from the existing highway embankment is to be maintained. Fills placed

near an existing granular fill (e.g. SGSB) should be free-draining granular material and extend a

minimum 100 mm in elevation below the bottom of adjacent existing granular fill so as to not block

internal drainage.

6.4.1 Embankment Fill East of Cache Creek (Station 407+450 to 408+880)

An embankment fill up to 12m in height is proposed for this section. Based on completed sub-surface

investigations in this area, the fill foundation materials are anticipated to consist of firm to very stiff,

intermediate plasticity silty clay soils. Laboratory analysis indicated that predominantly the upper 4 m is

considered over-consolidated, while the fine-grained material at depth was normally to slightly over-

consolidated. Cone (sCPTu) penetration testing yielded similar findings. The silty clay presents limitations

in terms of slope stability and possibly settlement for embankment construction. Shale bedrock underlies

the silty clay soil deposit at depths ranging from 3 m to 15.9 m, depending on location. The upper contact

of the shale is weathered and appears to have deteriorated to a residual clay-like soil. The lightly

weathered to fresh bedrock below appeared stronger but may have weak seams of bedding planes which

may also present limitations for embankment slope stability depending on depth and height of

embankment at any one location. See Table 6-1 for a summary of subsurface conditions.



Project # KX05280503 | 8/14/2019 Page 12

Table 6-1: Summary of Subsurface Conditions (Sta. 407+450 to 408+880)

Hole ID/

Sta

tio

n

Ele

vati

on

To

pso

il

Silt/Clay Sand/Gravel

Residual

Soil/Highly

Weathered

Shale

Lightly

Weathered to

Fresh Shale

and/or

Sandstone

BH18-A-051 407+540 474.3 0.2 0.2-2.1 (CH) 2.1-11.7 (SP-SM) 11.7->13.6 -

BH18-A-078 407+677 472.1 0.2 0.2-1.8 (ML) 1.8-10.2 (SP) 10.2->10.3 -

BH18-A-020 407+803 468.3 0.2 0.2-1.8 (CL) 1.8-4.9 (GP-GM) 4.9->6.1 -

TH16-A-055 407+896 464.4 0.3 0.3-3.1 (CL-CH) 3.1-3.6 3.6->5.2

BH16-A-026 407+996 463.0 0.3 0.3-3.2 (CH) 3.2-4.2 (SP-SM) 4.2-8.6 >8.6

TH16-A-056 408+002 461.9 0.2 0.2-3.0 (CH) - 3.0->4.6 -

BH16-A-027 408+129 459.8 0.3 0.3-1.1 (CL)

1.5-4.5 (CL) 1.1-1.5 (SM2) 4.5-6.1 >6.1

BH16-A-029 408+258 464.3 - 1.3 (CL)

1.3-5.7 (CH) - 5.7-7.4 >7.4

BH16-A-028 408+261 460.4 - 0.8-6.2 (CL-CH) 0.8 (GP)

6.3-7.0 (SP-SM) 7.0-7.5> -

TH16-A-057/ 408+382 466.7 0.5 0.5-3.0 (CL) - >3.0 -

BH16-A-030 408+377 464.4 0.2 0.2-5.8 (CL-CH) - 5.8-10.6 >10.6

BH16-A-032 408+505 473.8 0.3 0.3-6.7 (CL-CH) 6.7-7.5 (GP) 7.5-10.8 >10.8

BH16-A-031 408+500 471.6 0.2 0.2-9.0 (CL-CH) - 9.0-11.3 >11.3

TH16-A-058/ 408+625 482.0 0.3 0.3->5.2 (CL-CH) - - -

BH16-A-033 408+617 482.1 0.2

0.2-8.2 (CL-CH)

8.2-11.3 (BX*1)

11.3-12.5 (CL-CH)

12.5-15.9 (SM1) 15.9->19.8 -

TH16-A-060 408+741 492.4 0.3 0.3-6.7 (CL-CH) - - -

BH16-A-034 408+741 493.4 0.3

0.3-10.7 (CL-CH)

10.7-18.6 (BX*1)

18.6-24.5 (CL-CH)

24.5->24.8 (SM2) - -

TH16-A-059 408+859 494.9 0.2 0.2->5.2 (CL-CH) - - -

*1 – Landslide Debris

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



Project # KX05280503 | 8/14/2019 Page 13

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 using the proprietary computer program Slope/W by GeoSlope International Inc.

The Morgenstern half-slice function was used to resolve interslice forces. 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. A summary of the parameters

used in the stability analysis is provided in Table 6-2.

Table 6-2: Geotechnical Material Properties for Limit Equilibrium Slope Stability Analyses

Soil Type

Unit

Weight

(kN/m3)

Limit Equilibrium

Shear Strength

Model

Cohesion

(kPa)

Angle of

Internal

Friction (°)

Tau/Sigma

Ratio

Minimum

Strength

(kPa)

Embankment

Sand and Gravel

Fill

21 Mohr-Coulomb 0 36 - -

Clay/Silt 19 Mohr-Coulomb 0 22 - -

S=f(overburden) - - 0.22 35

Sand and Gravel 21 Mohr-Coulomb 0 37 - -

Weathered

Shale 24.5 Mohr-Coulomb 0 30 - -

Lightly

Weathered to

Fresh Shale

24.5 Anisotropic

Strength 50

45 (vertical)

35

(horizontal)

- -

RipRap 22 Mohr-Coulomb - 43 - -

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 long-

term 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 global short-term slope stability for a typical consequence slope with a typical degree of

understanding is 1.34, 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 were 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.



Project # KX05280503 | 8/14/2019 Page 14

Table 6-3: Summary of Limit Equilibrium Slope Stability Analyses for 3H:1V Embankment Fill Slopes

Station Design Case Required

FOS

No Berm

FOS

Berm

FOS

Minimum Berm

Dimensions

407+910 Normal

Operating Level

Effective Stress 1.54 1.59*1

N/A N/A

Undrained 1.33 1.63*1

Stage 2

Emergency

Drawdown

Effective Stress 1.24 1.59*1

Undrained 1.62*1

408+050 Normal

Operating Level

Effective Stress 1.54 1.44 1.57

6.0 m wide

3.6 m high

Undrained 1.33 1.45 1.61

Stage 2

Emergency

Drawdown


Undrained 1.24 1.38

408+120 Normal

Operating Level


9.25 m wide

2.6 m high

Undrained 1.33 1.37 1.44

Stage 2

Emergency

Drawdown


Undrained 1.18 1.37

408+200 Normal

Operating Level


8.75 m wide

2.8 m high

Undrained 1.33 1.29 1.43

Stage 2

Emergency

Drawdown


Undrained 1.16 1.28

1. Modify ditch design so that an open ditch (if required) is eliminated or located a minimum 15 m away from the right fill toe. An alternative

approach would be to install a swale/culvert rather than an excavation that compromises stability. A ditch at the left fill toe is not required for

geotechnical purposes, but if still needed should not be excavated at the toe of the fill.

To achieve target FoS in relation to possible rapid drawdown scenarios, where portions of the

embankment and/or its stability berm will be inundated by the reservoir there will be a requirement to

construct the embankment from free draining granular fill. In addition, maintenance of adequate slope

stability is also predicated upon preservation of the existing ground profile beyond the toes of the

proposed highway embankment. On the reservoir side of the embankment, there is a need to protect not

only the toe of the embankment where it will encroach on the reservoir but also protect some of the

intervening original ground that although it will not be inundated will still be subject to attrition by

longer-term shoreline erosion. It is anticipated that placement of the required stability berm and riprap

armouring of the embankment would address the majority of this potential issue.

Given the depth and thickness of the underlying clay and the height of the planned embankment,

consolidation settlement of the foundation soils is anticipated to occur. To estimate the anticipated

settlement, one-dimensional consolidation theory was used, with established parameters based on

laboratory consolidation testing, and sCPTu in-situ testing data. The worst-case estimate for a 16.8 m

embankment resulted in a maximum total settlement in the order of 200 mm, which would be expected

to be largely complete within 12 to 18 months of embankment completion. The analysis uses the

assumption that consolidation would not start until the end of embankment construction. Given the time

required to construct an embankment of this size, it is likely that consolidation would be complete

somewhat earlier. Analyses based on the sCPTu data suggested that the maximum total settlement would

be somewhat less, at 150 mm for a 16.8 m embankment.



Project # KX05280503 | 8/14/2019 Page 15

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

provided for embankment construction at this location:

The embankment and stability berm 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

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

improvements if any.

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

A non-woven geotextile (Class 2, as defined in Section 6.7, below), should be placed on the approved

subgrade before fill placement.

Embankment fill should be constructed at slopes no steeper than 3H:1V.

Between Sta. 407+920 and 408+620, a stability berm (approximately 2 m in height and 9.25 m wide,

with a maximum fill slope of no steeper than 3H:1V) should be constructed along the southern (right)

toe of the embankment.

The embankment fill height should not exceed the constructed height of the adjacent stability berm

by more than 1.0 m until after the stability berm has been completed to final design elevation.

Temporary internal fill placement slopes and ramp slopes shall not exceed 3 m in height if they are

constructed at slopes steeper than 3H:1V.

All portions of embankment and stability berm below elevation 466 m shall consist of clean granular

fill (CGF as defined in Section 6.4, above), having less than 5 % fines (passing 0.075 mm sieve). The

remaining fill material should have no more than 20 % fines (Type D as defined in Section 6.4 above).

For monitoring of stability and settlement, a program of geotechnical instrumentation is

recommended for the most critical portions of the embankment. The recommended instrumentation

program and protocol is provided in Section 6.9.1.

See Figure 5 (sheet 1) for typical section.

6.5 CUT SLOPES

Some shallow cuts up to 2 m and relatively minor ditch cuts of up to 2 m will be required for the currently

proposed alignment. The required cuts are expected to encounter mainly glaciofluvial and alluvial soils

(BCMoTI Type D excavation) that are generally anticipated to be unsuitable for use in the construction of

new highway embankments. For detailed design, the following recommendations are provided:

Unless otherwise specified in Section 6.10, use a maximum cut slope angle of 3H:1V.

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

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

slope from the base of the ditch to a minimum 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.



Project # KX05280503 | 8/14/2019 Page 16

6.6 GEOTEXTILE AND BIAXIAL GEOGRID SPECIFICATIONS Where non-woven geotextiles are required, the recommended specifications listed in Table 6-4, below

should be used.

Table 6-4: 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 6-5, below.

Table 6-5: 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 6-6 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 6-6: Recommended Minimum Pavement Structure Thickness

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



Project # KX05280503 | 8/14/2019 Page 17

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

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 general siting and placing waste from unsuitable or

surplus soil materials generated by the project. Specific disposal scenarios different from below should be

assessed on a case by case basis by a geotechnical engineer.

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).

Waste materials should be placed with a maximum slope of 3H:1V, and to a maximum height of

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

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 Cache Creek valley

slope crest, the main Peace River Valley sidewall slope located above and to the north of the proposed

alignment and/or along the crests of the slopes down to the Peace River, as these areas may be unstable.

Also, waste material should not be disposed of against the downstream (right side) toes of embankments

and stability berms where internal drainage of the embankment under static and rapid-drawdown reservoir

conditions is required.



Project # KX05280503 | 8/14/2019 Page 18

6.9 INSTRUMENTATION

6.9.1 New Instrumentation & Monitoring

To facilitate monitoring of stability and settlement of the fill area between Sta.407+450 and 408+880, a

program of instrument installation and monitoring during construction is recommended. Prior to fill

construction, and once the fill subgrade has been prepared, a series of vibrating wire piezometers (VWP)

paired with settlement plates (SP) fitted with steel riser survey pipe is recommended for the following five

locations:

SP/VWP 19-01 Sta. 408+000 offset 5 m Right (VWP at 5 m depth)





The vibrating wire piezometers should be installed by drilling through the prepared subgrade depths of

approximately 5 m and then fully grouting in the piezometers. After three days (to allow grout set-up and

piezometer stabilization), the settlement plates should be placed on the prepared subgrade on or near

the locations of the vibrating wire piezometers. The cables from the piezometers should be threaded up

through the steel riser pipes. The initial elevations of the settlement plates (and piezometer tips) should

then be determined by field survey. Fill can then proceed, with successive surveys, and additional lengths

of riser pipes added as required.

When the stability berm has been constructed to its design elevations, fill placement should be

temporarily suspended, and slope inclinometer (SI) casings should be installed by drilling and grouting

through the top of the stability berm to 15 m deep at the following four locations at or near the rear of

the berm:

SI 19-01 Sta. 408+000 offset 30 m Right (SI to 15 m depth)




Fill placement should not resume until at least three days after the slope inclinometer casings have been

installed and initial surveys conducted.

A geotechnical engineer should coordinate and review the monitoring program. After initial

measurements, the frequency of successive measurements and requirements are for adjustments to the

construction operations (if any) will be determined by the geotechnical engineer based on fill placement

rates and results from the monitoring. As a preliminary guide, it is considered that fill placement would be

suspended for a period of at least one week after placement of each successive 3.0 vertical meters of fill

above the completed elevation of the adjacent stability berm to allow the analysis of monitoring results.



Project # KX05280503 | 8/14/2019 Page 19

6.9.2 Protection of Existing Instrumentation

Geotechnical instrumentation in the form of piezometers (vibrating wire and standpipes) and plastic (PVC)

site investigation casings have been installed during this and previous phases of site investigation. Some

of these locations should be preserved for additional monitoring during construction and post-

construction. The instrument locations to be preserved for future use include:

BH16-A-026 – Station 408+000 offset 45 m Left (VWP)

BH16-A-028 – Station 408+260 offset 90 m Right (VWP)



6.10 DETAILED GEOTECHNICAL RECOMMENDATIONS BY STATION

SECTION

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

in Table 6-7 on the following pages.



Project # KX05280503 | 8/14/2019 Page 20

Table 6-7: Detailed Geotechnical Recommendations by Station Section

Station Range Reference Geometric

Design Configuration

Representative

Geotechnical

Investigation

Anticipated Subsurface Conditions Geotechnical Recommendations

From To

407+334 407+500

Fill up to 5 m high

3H:1V Fill Slopes and up to

3 m ditch cuts 3H:1V BH18-A-019, BH18-A-078

Upper 0.2 m: Topsoil.

Below Topsoil: 1.1 to 1.9m of high plasticity SILT and CLAY.

Below Silt and Clay: approx. 6 m of SAND and GRAVEL over SHALE BEDROCK.

Bedrock at elev. 461.9 m to 463.0 m.

Groundwater not encountered during drilling.

Stripping Typically 2.1 m, maybe locally deeper. Subgrade to be

reviewed and approved by a geotechnical engineer.

Max Fill Slopes 3H:1V. Use granular fill.

407+500 407+700

Scatch grade/ Cuts up to

2 m

3H:1V Cut Slope

BH18-A-051

Upper 0.2 m: Topsoil

Below Topsoil: 2.0 m of high plasticity CLAY.

Below Clay: 9.6 m of GRAVEL and SAND over SHALE BEDROCK.

Bedrock ay elev. 462.6 m.

Groundwater encountered at Elev. 463.6 m.

Stripping Typically 2.1 m, maybe locally deeper.

Subgrade to be reviewed and approved by a geotechnical

engineer.

Max Cut Slopes 3H:1V.

407+450 408+880 Fill up to 12 m in height

3H:1V Fill Slopes

TH16-A-054 to TH16-A-062

BH16-A-026 to BH16-A-034

CPT16-A-003 to CPT16-A-

005

Upper 0.2 m: Topsoil.

Below Topsoil: 2.5 to 10.4 m of SILT and CLAY, with minor sand and gravel, increasing thickness to east.

Below Silt and Clay: SHALE BEDROCK (irregular profile, encountered between elev. 453.4 m and 466.3

m).

NOTE - north of approx. Stn. 408+617 buried landslide COLLUVIUM (several meters of weathered shale

within a thick silt and clay sequence) appears to have been encountered (8.2 - 11.3 m depth in BH16-A-

033, and 10.7 - 18.6 m depth in BH16-A-034) between elevations ranging between 471 and 483 m.

Groundwater encountered at some locations (approx. elev. 459.4 m in BH16-A-026; 467.7 m in BH16-A-

031; 464.7 m in BH16-A-032; 482.9 m in BH16-A-034; 463.9 m in TH16-A-057).

Stripping: Typically, 0.3 m, may be locally deeper.

Subgrade to be reviewed and approved by a geotechnical

engineer.

Approved subgrade to be covered with a non-woven geotextile.

Max Fill Slopes 3H:1V. Use granular fill.

Requires a granular stability berm on right side between Stn.

407+920 and 408+620.

Requires riprap protection on right side between Stn. 407+895 and

408+345.

Requires geotechnical instrumentation and monitoring.

SEE REPORT SECTION 6.9.1 FOR MORE DETAIL

408+880 409+143.892

Side slope transition

onto existing Highway 29

fill

Fill up to 10 m in height

on left (Side slope)

3H:1V Fill Slopes

TP16-A-061 to TP16-A-064

BH16-A-035 to BH16-A-036

Upper 0.3 m at the toe of existing fill: Topsoil

Below Topsoil adjacent to toe of existing fill: 7 to 8 m of SILT and CLAY over SHALE BEDROCK

Under Highway 29: up to 8.8 m of CLAY, FILL over fine-grained COLLUVIUM and SHALE BEDROCK.

NOTE - Buried landslide COLLUVIUM (several meters of weathered shale within a silt and clay

sequence) appears to have been encountered (8.8 - 13.1 m depth in BH16-A-035, and 7.9 - 12.8 m

depth in BH16-A-036) between elevations ranging between 505 and 512 m.

Bedrock elevation variable, encountered from elev. 498.8 to 504.6 m.

Groundwater encountered near elev. 494 m, in BH16-A-036.

Stripping: Typically, 0.3 m, 0.5 m on face of existing highway fill.

Max. Fill Slopes 3H:1V, use granular fill.

Requires side slope terracing on face of existing fill, potential for

additional sub-excavation to remove weak/wet pockets.



Project # KX05280503 | 8/14/2019 Page 22

REFERENCES Amec Foster Wheeler. (5 March 2012). Preliminary Geotechnical Assessment Proposed Bear Flat Segment

Highway 29 Definition Design.

Amec Foster Wheeler. (19 January 2017). Gravel Investigation – Lower Cache Creek Gravel Borrow

Prospect Highway 29: Bear Flat – Cache Creek.

Amec Foster Wheeler. (27 January 2017, revised 20 April 2018). Gravel Resource Assessment Peaceview Pit

Prospect Highway 29 Bear Flat to Cache Creek.

Amec Foster Wheeler. (21 July 2017). Geotechnical Assessment and Design Highway No. 29 Bear Flat –

Cache Creek.

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

Report, University of Alberta.

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.

Wood Environment and Infrastructure Solutions. (14 Aug 2019). Highway 29, Bear Flat Cache Creek

Segment, Geotechnical Data Report.

Appendix A

Figures

DesignAlignment

Hwy 29Peaceview PitProspect

Lower Cache CreekGravel Borrow Prospect

Ha l f

w a y R ive

r

C a c h e C r e e k

P e a c e R i v e r

C h a r l i eL a k e

Notes:1. L4000O43 centreline alignment provided by R.F. Binnie & Associates CAD file '20190624 - Alignment and Toes for Wood.dwg', received 24 June 2019.2. Bing Maps Road - © 2018 Microsoft Corporation © 2018 HERE.

LegendL4000O43 Centreline Alignment

!(

!(

!(

!(

!(

_̂

VancouverKamloops

ChetwyndFort St John

PrinceGeorge

ProjectLocation

This drawing was originally produced in colour.

CLIENT:

\\Prg-fs1\cad\Internal\KX052805-GIS\4CacheCreek\CCE-AlignGeotechInvest-DetDes-Fig1-SiteLocationPlan.mxd

SCALE:

PROJECTION:

DATUM:

CHK'D BY:

DWN BY: TITLE:

PROJECT:REV NO.:

PROJECT NO.:

DATE:

HIGHWAY NO. 29BEAR FLAT CACHE CREEKUTM Zone 10

NAD 83

KS

BB SITE LOCATION PLANGEOTECHNICAL INVESTIGATION

A

FIGURE 1

KX05280503

AUGUST 2019

$

1:200,000

0 4 8 12 162km

3456 Opie CrescentPrince George, BC, CANADA V2N 2P9Tel. (250) 564-3243 Fax (250) 562-7045

WoodEnvironment & Infrastructure Solutions

a Division of Wood Canada Limited (Wood)

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


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

407+000

407+500

408+000

408+500

409+000

!A

!A

!A

!A!A

!A

!A

!A

!A

")

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")

")

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")

")

")

!A

!A

!A

!A

!A

!A

!A

!A!A

!A

!A!A

#*

#*

#*

!A

!A

!A

!A

!A

!A

!A

!A

!A

!A

!A!A

!A

!A

!A

!A

!A

!A

!A

!A

!A

!A

!A

!A

!A

!A

!A

(See Note 1)

Highway 29

Ca c h e

Cr e

ek

BH17-A-001

DH-33

92-01

92-02

92-0392-04 92-05

92-06

92-07

92-08

PV16-025

PV16-028

PV16-029

PV16-031

PV16-030

PV16-026

PV16-032

PV16-027

BH18-A-014

BH18-A-017

BH18-A-019

BH18-A-020

BH18-A-043

BH18-A-046

BH18-A-051

BH18-A-073BH18-A-077

BH18-A-078

BH16-A-025

BH16-A-026

BH16-A-027

BH16-A-028

BH16-A-029

BH16-A-030BH16-A-031

BH16-A-032BH16-A-033

BH16-A-034

BH16-A-035BH16-A-036

TH16-A-051

TH16-A-052

TH16-A-053

TH16-A-054

TH16-A-055

TH16-A-056

TH16-A-057

TH16-A-058

TH16-A-059

TH16-A-060

TH16-A-061

TH16-A-062

TH16-A-063

TH16-A-064

BH17-A-002

BH17-A-003

CPT16-A-003

CPT16-A-004

CPT16-A-005

PROJECTION:

DATUM:

CHK'D BY:

DWN BY:


CLIENT: DATE:

KX05280503

AUGUST 2019

A

SITE PLAN WITH ORTHOPHOTOGEOTECHNICAL INVESTIGATION

HIGHWAY NO. 29BEAR FLAT CACHE CREEK

FIGURE 2

TITLE:

PROJECT:

UTM Zone 10

NAD 83

KS

BBPROJECT NO.:

REV NO.:

1:5,000\\Prg-fs1\cad\Internal\KX052805-GIS\4CacheCreek\CCE-AlignGeotechInvest-DetDes-Fig2-SitePlan-Ortho.mxd

SCALE:

0 130 260 390 52065m

Notes:1. Survey by WSP.2. Hole location provided by handheld GPS.3. L4000O43 centreline alignment and slope stake lines provided by R.F. Binnie & Associates CAD file '20190624 - Alignment and Toes for Wood.dwg', received 24 June 2019.4. Maximum Normal Reservoir Level (461.8 m) downloaded from BC Hydro SharePoint 11 April 2018.5. Orthophoto imagery provided by BC Hydro 9 January 2018.

BC HYDRO c/o R.F. BINNIE & ASSOCIATES LTD.Legend!A 2018 Borehole Location !A 2016/2017 Borehole Location

#* 2016 CPT Location

") 2016 Pavement Core Location

!A Historical Drillhole LocationL4000O43 Centreline AlignmentL4000O43 Slope Stake LineMaximum Normal Reservoir Level (461.8 m)

$

407+200 407+300 407+400 407+500 407+600 407+700

430

440

450

460

470

430

440

450

460

470

420 420

407+150 407+250 407+350 407+450 407+550 407+650

Elevation (m

)

Station (m)

Elevation (m

)

407+100407+050

410 410

480 480

C a c h e C r e e k

Cross Section

Station 407+330

See Figure 4 Sheet 1

TSCL

GP

BREND

Water Level5/18/2018

0.31.6

9.710.8

183244485028223338352126

RRRR

19151111

11212

39

256

m

BH18-A-017N WW TS

CH

SP-SM

BREND


0.2

2.1

11.7

13.6

1624817533353468

56

33

R

R

R

2017111211

2

2

6

6

13

23 65

m

BH18-A-051N WW PL LL

TSCH

GM1

GP

BR

END


0.2

2

5.8

9.9

60.9

153178364738

53

33

33R

28232124

3

3

59

26 63

0.91 / 1.630.23 / 0.72

0.30 / 0.91

0.24 / 0.60

0.30 / 0.77

N/A / N/A

0.21 / 0.89

0.22 / 0.28

0.05 / 1.55

0.14 / 0.90

0.17 / 1.21

0.10 / 0.31

0.13 / 0.63

0.15 / 0.96

0.20 / 0.50

0.06 / 1.32

0.18 / 1.87

0.19 / 1.25

0.08 / 2.33

1.80 / 2.00

1.66 / 2.42

0.91 / 2.24

1.33 / 3.14

0.15 / 1.04

0.20 / 1.52

0.25 / 1.30

0.16 / 1.82

0.23 / 0.65

0.08 / 1.21

0.41 / 1.80

0.08 / 1.72

0.23 / 2.07

0.15 / 2.09

0.48 / 1.83

m

BH18-A-073N WW PL LL Is50Is50

Dia/Axial CH

GP-GM

BR

END


2.4

10.2

27.3

172131512626

53

52

25

R

292116144

3

4

3

10

25 63

0.15 / 0.10

0.12 / 0.52

0.09 / 0.23

0.26 / 0.18

0.10 / 0.03

0.11 / 0.68

0.77 / 1.34

0.07 / 0.76

0.18 / 0.56

0.15 / 0.62

0.14 / 0.80

m


Dia/Axial

TSML

SP

BR

0.2

1.8

10.210.3

85

38454749

37

47

R

R

25344332

4

3

6

8

m

BH18-A-078N WW

END

(MPa)(MPa)

N/A

PROJECTION:

N/A

DATUM:

PROFILE

STATION 407+050 TO 407+700

GEOTECHNICAL INVESTIGATION

PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29

BEAR FLAT CACHE CREEK


Legend

L4000O43P3 Centerline Alignment Profile

Existing Ground Profile at Centreline

FIGURE 3

SHEET NO. 1 of 4

Wood Environment & Infrastructure Solutions



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

0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Notes:

1. SPT N values and associated laboratory testing data provided with the Sticklogs may not be

presented at representative elevations. Please refer to Geotechnical Data Report (July 2019)

Appendix B – Investigation Logs for additional details.

2. L4000O43P3 centreline alignment profile and existing ground profile provided by R.F. Binnie &

Associates Ltd. CAD file '20190624 - Alignment and Toes for Wood.dwg', received 24 June

2019.

407+800 407+900 408+000 408+100 408+200 408+300

460

470

480

460

470

480

450 450

407+850 407+950 408+050 408+150 408+250

440 440

Elevation (m

)

Station (m)

Elevation (m

)

407+700 407+750 408+350

TSCL

GP-GM

BREND


0.2

1.8

4.96.1

11226759

61RRR

102RR

2420112

10

10

m

BH18-A-020N WW


0.3

3.24.2

19.7

TS

CH

SP-SM

BR

15

3

2222253530208

23 57

m


0.31.11.5

4.5

13.6

TSCL

CL

BR

18

55

128189106

20 38

m


1.3

5.7

30.2

CL

CH

BR

1215

21

232428

20

29

39

57

m

BH16-A-029WW PL LL

0.3

3.13.65.2

TS

CL-CH

BR

15

12

44

2020222519187

129

m

TH16-A-055N WW

END

END

END

END

SM2

SM2

Cross Section

Station 408+260


0.10 / 0.656.37 / 0.16

0.70 / 0.84

4.37 / 0.27

0.03 / 0.39

Is50Is50Dia/Axial

(MPa)

0.19 / 0.12

0.10 / 0.94

0.18 / 0.22

0.06 / 0.28

Is50Is50Dia/Axial

(MPa)

0.18 / 0.50

0.03 / 0.29

0.08 / 0.47

0.04 / 0.55

0.19 / 0.59

0.44 / 0.94

0.13 / 0.42

0.12 / 0.54

0.12 / 0.23

0.05 / 0.26

1.38 / 3.10

0.12 / 0.74

0.11 / 0.38

0.20 / 0.72

Is50Is50Dia/Axial

(MPa)

N/A

PROJECTION:

N/A

DATUM:

PROFILE

STATION 407+700 TO 408+350


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29



FIGURE 3

SHEET NO. 2 of 4





0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Legend



Notes:






2019.

408+400 408+500 408+600 408+700 408+800

490

500

510

520

490

500

510

520

480 480

408+450 408+550 408+650 408+750

470 470

Elevation (m

)

Station (m)

Elevation (m

)

408+350 408+850 408+900 408+950 409+000

460 460


0.3

6.77.5

19.6

TS

CL-CH

GP

BR

15191816

17

17

30

110R

13131513161412181821202224147

27

18

57

41

m



0.3

10.7

18.6

24.524.8

TS

CL-CH

BX

CL-CH

SM2

17151529

12

15

14

13

14

8

15

15

21

26

21

810127

10668

131413181419161416201921222218

21

20

18

23

23242724

24

19

21

21

20

49

41

34

38

35

m



0.10.5

8.8

13.114.5

30.6

APSP

CL

BX

CL

BR

108

10

11

11

11

12

9

21

18

16

24

182015

15

17

19

21

20

22

27

27

20

2020

18

19

20

2321

36

35

39

3939

m



0.5

3

5.2

TS

CL

BR

10

9

6

222325304019

m

TH16-A-057N WW

0.3

5.2

TS

CL-CH16

15

9

10149

111513

24 45

m

TH16-A-058N WW PL LL

0.3

5.5

TS

CL

6

21

914

10101014

m

TH16-A-063N WW

END

END

END

END

END

ENDTS

CL

0.3

5.2 9

12

10

14

m

TH16-A-062N WW

Cross Section

Station 408+380


Cross Section

Station 408+500


0.23 / 0.56

0.15 / 0.52

0.08 / 0.71

0.77 / 0.93

0.33 / 0.54

Is50Is50Dia/Axial

(MPa)

N/A

PROJECTION:

N/A

DATUM:

PROFILE

STATION 408+350 TO 409+000


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29



FIGURE 3

SHEET NO. 3 of 4





0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Legend



Notes:






2019.

409+000

510

520

530

510

520

530

409+050

Elevation (m

)

Station (m)

Elevation (m

)

409+100 409+150 409+200 409+250 409+300 409+350 409+400 409+450 409+500 409+550 409+600 409+650

540 540

Highway 29

0.3

4.9

TS

CL21

20

9

141113121814

m

TH16-A-064N WW

END

N/A

PROJECTION:

N/A

DATUM:

PROFILE

STATION 409+000 TO 409+650


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29



FIGURE 3

SHEET NO. 4 of 4





0m 25 50 75 100

H 1 : 2000

V 1 : 400

0m 5 10 15 20

Legend



Notes:






2019.

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

Elevation (m

)

460

440

420

-80

Elevation (m

)

460

440

420

480 480

TS

GP

BR

0.4

8.2

61.1 END

47412748R474854R

2222112

13

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

0.23 / 0.280.18 / 0.380.36 / 1.110.25 / 1.740.51 / 2.380.14 / 0.790.23 / 0.450.55 / 0.870.25 / 0.630.08 / 0.550.10 / 0.620.09 / 0.830.17 / 1.060.19 / 1.420.08 / 0.920.27 / 0.840.28 / 0.830.13 / 0.610.50 / 0.851.11 / N/AN/A / N/A

0.42 / 1.05N/A / N/A

0.36 / 0.480.05 / 1.200.13 / 2.130.21 / 2.400.04 / 2.040.45 / 2.010.27 / 2.080.47 / 2.420.20 / 2.270.41 / 2.100.16 / 2.25

m

BH18-A-014N WW Is50Is50

Dia/AxialTS CL

GP

BR

0.22.4

10.8

50.3 END


193173321025R48

50R90R

1715101022434

107

0.30 / 0.570.32 / 0.720.33 / 0.450.19 / 0.280.07 / 0.790.65 / 1.380.56 / 1.590.41 / 0.620.04 / 1.480.16 / 0.290.19 / 0.430.11 / 0.300.21 / 1.050.13 / 0.070.28 / 1.030.16 / 0.290.12 / 1.010.33 / 1.220.14 / 0.820.26 / 2.240.95 / 2.860.36 / 0.751.19 / 1.620.04 / 0.880.08 / 1.010.09 / 1.44

m


Dia/Axial TS CL

GP

BR

0.22.1

10.2

61 END


23295027674134

100R21R

1815113242588

0.15 / 0.630.07 / 0.480.15 / 0.770.07 / 0.930.01 / 0.350.12 / 0.340.14 / 1.010.19 / 0.150.18 / 0.280.10 / 0.390.01 / 0.310.10 / 0.850.10 / 0.340.09 / 1.110.24 / 1.960.02 / 1.280.16 / 0.870.25 / 1.170.15 / 1.511.78 / 0.880.94 / 2.130.70 / 0.840.22 / 0.540.01 / 0.270.18 / 0.900.16 / 0.810.17 / 1.300.20 / 0.410.01 / 0.960.27 / 0.950.29 / 0.890.21 / 1.380.35 / 1.34

m


Dia/Axial TS CHGM1

GP

BR

0.22

5.8

9.9

60.9 END


153178364738533333R

282321243359

26 63

0.91 / 1.630.23 / 0.720.30 / 0.910.24 / 0.600.30 / 0.77N/A / N/A

0.21 / 0.890.22 / 0.280.05 / 1.550.14 / 0.900.17 / 1.210.10 / 0.310.13 / 0.630.15 / 0.960.20 / 0.500.06 / 1.320.18 / 1.870.19 / 1.250.08 / 2.331.80 / 2.001.66 / 2.420.91 / 2.241.33 / 3.140.15 / 1.040.20 / 1.520.25 / 1.300.16 / 1.820.23 / 0.650.08 / 1.210.41 / 1.800.08 / 1.720.23 / 2.070.15 / 2.090.48 / 1.83

m


Dia/Axial

Offset (m)

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

℄L4000O43

407+330

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

STATION 407+330


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

AS NOTED

BB

HIGHWAY NO. 29



Legend


FIGURE 4

SHEET NO. 1 of 4





100m 5 2015

H 1 : 500

V 1 : 1000

200m 10 4030

Notes:

1. Existing ground (main) provided by R.F. Binnie & Associates Ltd. CAD file

'CCE-L4000O41p2-XS_WOOD.dwg', received 21 November 2018.

2. Additional existing ground (approximate) processed from LIDAR (UTM) provided by

BC Hydro 9 January 2018.

℄

440

480

Elevation (m

)

460

440

480

Elevation (m

)

460

-60 -40 -20 0 20 40 60-80

Offset (m)

-100-120 80 100 120

CPT16-A-004

Avg qt(kPa) Avg fs

(kPa)100005000 250 500

5

Refusal

GP

CL-CH

SP-SMBR

0.8

6.37

10.7

71015171714131130

2524282324281524810

2626

23

4452

58

0.06 / 0.681.8 / 1.65

m


Dia/Axial

CL

CH

BR

1.3

5.7

30.2

121521232428

20

29

39

57

0.18 / 0.500.03 / 0.290.08 / 0.470.04 / 0.550.19 / 0.590.44 / 0.940.13 / 0.420.12 / 0.540.12 / 0.230.05 / 0.261.38 / 3.10

0.12 / 0.740.11 / 0.380.20 / 0.72

m

BH16-A-029WW PL LL Is50Is50

Dia/Axial

END

END

L4000O43

408+260

(MPa)

(MPa)

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

STATION 408+260


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

1:750

BB

HIGHWAY NO. 29



FIGURE 4

SHEET NO. 2 of 4





Legend

Typical Cross Section Based on L4000O43 Centerline Alignment


Notes:

1. Typical cross section based on L4000O43 centerline alignment and existing ground

profile at centreline provided by R.F. Binnie & Associates Ltd. CAD file '20190624 -

L4000O43 Cross Sections.dwg', received 24 June 2019.

2. Additional existing ground profile at centreline (approximate) processed from LIDAR

provided by BC Hydro 9 January 2018.

1 : 750

5 1510 20 25 300m

440

480

-60 -40 -20 0 20 40 60-80

Offset (m)

80

℄L4000O43

460

Elevation (m

)

TSCL

BR

0.5

3

5.2Water Level

4/30/2016

10

9

6

222325304019

m

TH16-A-057N WW

END

TS

CL-CH

BR

0.2

5.8

15.1

182224252931196

18

26

28

62

0.06 / 0.110.09 / 0.570.14 / 0.460.33 / 0.51

m


Dia/Axial

440

480

460

Elevation (m

)

408+380

(MPa)

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

STATION 408+380


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

1:600

BB

HIGHWAY NO. 29



FIGURE 4

SHEET NO. 3 of 4





Legend



24181260m

1 : 600

Notes:

1. Typical cross section based on L4000O43 centerline alignment and existing ground

profile at centreline provided by R.F. Binnie & Associates Ltd. CAD file '20190624 -

L4000O43 Cross Sections.dwg', received 24 June 2019.

2. Additional existing ground profile at centreline (approximate) processed from LIDAR

provided by BC Hydro 9 January 2018.

460

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

Offset (m)

80

℄L4000O43

Elevation (m

)

450

470

460

Elevation (m

)

450

470

480 480

Avg qt(kPa) Avg fs

(kPa)100005000 250 500

Refusal

5

CPT16-A-005(See Note 1)

TS

CL-CH

BR

0.2

9

19.3

161486

8

6

23

R

131214122227242426222125283027143116151012

21

21

21

45

44

47

0.03 / 0.500.21 / 0.440.28 / 1.240.25 / 0.970.29 / 0.92

m


Dia/Axial

TS

CL-CH

GP

BR

0.3

6.77.5

19.6


15191816

17

1730

110R

13131513161412181821202224147

27

18

57

41

0.23 / 0.560.15 / 0.520.08 / 0.710.77 / 0.930.33 / 0.54

m


Dia/Axial

END

END

408+500

(MPa)

(MPa)

N/A

PROJECTION:

N/A

DATUM:

CROSS SECTION

STATION 408+500


PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

1:500

BB

HIGHWAY NO. 29



FIGURE 4

SHEET NO. 4 of 4





Legend



100m 5

1 : 500

2015

Notes:

1. Hole location provided by ConeTec.

2. Typical cross section based on L4000O43 centerline alignment and existing ground profile at

centreline provided by R.F. Binnie & Associates Ltd. CAD file '20190624 - L4000O43 Cross

Sections.dwg', received 24 June 2019.

3. Additional (approximate) existing ground profile at centreline processed from LIDAR provided

by BC Hydro 9 January 2018.

PROPERTY TEST METHOD CLASS 2

Material Type

Non-Woven ¹Grab Tensile Strength ²

ASTM D 4632> 700N

Sewn Seam Strength ²

ASTM D 4632> 630N

Tear Strength ²

ASTM D 4533> 250N

Puncture Strength ²

ASTM D 6241> 1375N

Permittivity

ASTM D 4491> 0.1 sec ¹

Apparent Opening Size ³

ASTM D 4751 < 0.22mm

Recommend Application

Drainage layers subgrade

separation -50 kg class riprap

Pavement Structure

3H:1V

El. 466m

Type D Granular Fill

(<20% fines)

Settlement Plate

New VWP

(To be installed prior

to fill placement)

Clean Granular Fill (<5% fines)

3H:1V

El. 466m

Original Ground

Stripping

300mm (min)

subgrade to be

approved by

Geotechnical

Engineer

Non-woven

geotextile

(Class 2)

New SI Casing

(To be installed after

the completion of the

stability berm)

20H:1VRiprap

Stability Berm

min 2m, max 4m thick

3H:1V

Highway Embankment

(See Note 1)

SGSB (minimum 600 mm)

Note 1: Until the Stability Berm is constructed to the final design height, Highway Embankment fill height is not to exceed 1.0 m above the Stability Berm height.

Recommended Geotextile Specifications

N/A

PROJECTION:

N/A

DATUM:

TYPICAL SECTION BETWEEN

STATION 407+920 TO STATION 408+620

PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

AS NOTED

BB/NW

HIGHWAY NO. 29



FIGURE 5

SHEET NO. 1 of 2





Sieve Size

(mm)

Percent Passing

by Weight (%)

150 100

75 50 - 100

50 30 - 100

19 20 - 100

4.75 10 - 60

1.18 6 - 32

0.300 3 - 15

0.075 0 - 5

PROPERTY TEST METHOD CLASS 2

Material Type

Non-Woven ¹Grab Tensile Strength ²

ASTM D 4632> 700N

Sewn Seam Strength ²

ASTM D 4632> 630N

Tear Strength ²

ASTM D 4533> 250N

Puncture Strength ²

ASTM D 6241> 1375N

Permittivity

ASTM D 4491> 0.1 sec ¹

Apparent Opening Size ³

ASTM D 4751 < 0.22mm

Recommend Application

Drainage layers subgrade

separation -50 kg class riprap

2.0m (min)

Seepage

Zone

Place parallel to

prepared cut slope

Top of cut

Non-woven geotextile

(Class 2)

2.0m (min)

Top of seepage zone

1m (min)

Seepage

Zone

Place parallel to

prepared slope

Perforated PVC drain (if required)

Top of fill

Drainage Blanket

Non-woven geotextile

(Class 2)

Top of seepage zone

Prepared existing fill

slope or subgrate

Designed fill

1m (min)

Maintain design ditch

Existing

Cut Slope

See Note 6

Drainage Blanket

N/A

PROJECTION:

N/A

DATUM:

TYPICAL SECTIONS

GRANULAR DRAINAGE BLANKET DETAILS

PROJECT:

TITLE:

REV. NO.:

PROJECT NO.:

KX05280503

A

CLIENT:

DWN BY:

CHK'D BY:

AUGUST 2019

DATE:

SCALE:

KS

AS NOTED

BB/NW

HIGHWAY NO. 29



FIGURE 5

SHEET NO. 2 of 2





Notes:

1. Seepage zones are to be reviewed by a Geotechnical Engineer or their representative at

the time of construction prior to covering with geotextile and drainage blanket.

2. Free-draining drainage blanket is to be a minimum of 1.0m thick or as required by the

Geotechnical Engineer.

3. Drainage blanket should be keyed into cut slopes to accommodate ditch width.

4. The drainage blanket is for control of seepage and potential internal erosion only and

should not be designed to be used as a buttress for additional toe support.

5. Extend drainage blanket laterally and horizontally a minimum 2.0m beyond seepage zone.

6. A geotextile between drainage blanket and general embankment fill (placed adjacent and

downslope of the drainage blanket) may be omitted if the general embankment fill contains

<5% fines (material passing the 0.075mm sieve size).

TYPICAL GRANULAR DRAINAGE BLANKET DETAIL

FOR FILL SLOPE

TYPICAL GRANULAR DRAINAGE BLANKET DETAIL

FOR CUT SLOPE

Recommended Geotextile Specifications

Notes:

Drainage Blanket Gradation

Appendix B

Slope Stability Outputs

1.593

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 407+910.gszName: 4. Sta. 407+910_(Maximum Normal Reservoir Level_Effective Stress) (No Ditch)

Color Name Model Unit Weight (kN/m³)

Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)

1. Fill Mohr-Coulomb 21 0 36 0 1

2. Clay/Silt (Effective Stress)_High Plastic

Mohr-Coulomb 19 0 22 0 1

3. Weathered Bedrock

Mohr-Coulomb 24.5 0 30 0 1

4. Shale Bedrock Anisotropic Strength 24.5 0 1 50 50 35 45

1.632

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 407+910.gszName: 5. Sta. 407+910_(Maximum Normal Reservoir Level_Undrained) (No Ditch)


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio

MinimumStrength (kPa)

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)


2. Clay/Silt (Undrained)_High Plastic

S=f(overburden) 19 1 0.22 35




1.587

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 407+910.gszName: 6a. Sta. 407+910_(Rapid Drawdown) No ditch (Effective Stress)


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.618

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 407+910.gszName: 6b. Sta. 407+910_(Rapid Drawdown) No ditch. (Undrained)


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.435

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 408+050..gszName: 7. Sta. 408+050_Full Supply Level_No Berm

Color Name Model Unit

Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Phi-B

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)


2. Clay/Silt (EffectiveStress)_High Plastic





1.451

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 408+050..gszName: 8. Sta. 408+050_Full Supply Level_Undrained_No Berm


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Phi-B

(°)

Piezometric

Line

Tau/Sigma

Ratio

Minimum

Strength

(kPa)

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)







1.082

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 408+050..gszName: 9a. Sta. 408+050_Rapid Drawdown_No Berm (Effective Stress)


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Phi-B

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)







1.237

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 408+050..gszName: 9b. Sta. 408+050_Rapid Drawdown_No Berm (Undrained)


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Phi-B

(°)

Piezometric

Line

Tau/Sigma

Ratio

Minimum

Strength

(kPa)

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)







1.571

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 408+050..gszName: 4. Sta. 408+050_Full Supply Level_Berm Resize


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Phi-B

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)







1.611

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 408+050..gszName: 5. Sta. 408+050_Full Supply Level_Berm Resize_Undrained


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Phi-B

(°)

Piezometric

Line

Tau/Sigma

Ratio

Minimum

Strength

(kPa)

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)







1.242

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 408+050..gszName: 6a. Sta. 408+050_Rapid Drawdown_Fully Specified_Berm Resize (Effective Stress)


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Phi-B

(°)

Piezometric

Line

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)







1.383

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/7/2019Last Edited By: Sinclair, KimFile Name: 408+050..gszName: 6b. Sta. 408+050_Rapid Drawdown_Fully Specified_Berm Resize (Undrained)


Weight

(kN/m³)

Cohesion'

(kPa)

Phi'

(°)

Phi-B

(°)

Piezometric

Line

Tau/Sigma

Ratio

Minimum

Strength

(kPa)

C-Horizontal

(kPa)

C-Vertical

(kPa)

Phi-Horizontal

(°)

Phi-Vertical

(°)







1.401

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200420

430

440

450

460

470

480

KX05280503.7

Highway 29. Bear Flat Cache Creek Segment

Date: 5/7/2019

Last Edited By: Sinclair, Kim

File Name: 408+120.gsz

Name: 7. Sta. 408+120_Full Supply Level_No Berm


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.365

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200420

430

440

450

460

470

480

KX05280503.7


Date: 5/7/2019



Name: 8. Sta. 408+120_Undrained_No Berm


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.079

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200420

430

440

450

460

470

480

KX05280503.7


Date: 5/7/2019



Name: 9a. Sta. 408+120_Rapid Drawdown_No Berm (Effective Stress)


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.178

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200420

430

440

450

460

470

480

KX05280503.7


Date: 5/7/2019



Name: 9b. Sta. 408+120_Rapid Drawdown_No Berm (Undrained)


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.552

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200420

430

440

450

460

470

480

KX05280503.7


Date: 5/7/2019



Name: 4. Sta. 408+120_Full Supply Level_Berm Resize


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.443

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200420

430

440

450

460

470

480

KX05280503.7


Date: 5/7/2019



Name: 5. Sta. 408+120_Undrained


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.248

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200420

430

440

450

460

470

480

KX05280503.7


Date: 5/7/2019



Name: 6a. Sta. 408+120_Rapid Drawdown_Berm Resize (Effective Stress)


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.372

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200420

430

440

450

460

470

480

KX05280503.7


Date: 5/7/2019



Name: 6b. Sta. 408+120_Rapid Drawdown_Berm Resize (Undrained)


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.385

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100445

450

455

460

465

470

475

445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/8/2019Last Edited By: Sinclair, KimFile Name: 408+200..gszName: 7. Sta. 408+200_Full Supply Level_No Berm


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.285

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100445

450

455

460

465

470

475

445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/8/2019Last Edited By: Sinclair, KimFile Name: 408+200..gszName: 8. Sta. 408+200_Full Supply Level_Undrained_No Berm


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.162

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100445

450

455

460

465

470

475

445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/8/2019Last Edited By: Sinclair, KimFile Name: 408+200..gszName: 9a. Sta. 408+200_Rapid Drawdown_No Berm (Effective Stress)


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.163

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100445

450

455

460

465

470

475

445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/8/2019Last Edited By: Sinclair, KimFile Name: 408+200..gszName: 9b. Sta. 408+200_Rapid Drawdown_No Berm (Undrained)


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.544

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100445

450

455

460

465

470

475

445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/8/2019Last Edited By: Sinclair, KimFile Name: 408+200..gszName: 4 Sta. 408+200_Full Supply Level_Berm Re-size


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.425

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100445

450

455

460

465

470

475

445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/8/2019Last Edited By: Sinclair, KimFile Name: 408+200..gszName: 5. Sta. 408+200_Full Supply Level_Undrained_Berm Re-size


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.331

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100445

450

455

460

465

470

475

445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/8/2019Last Edited By: Sinclair, KimFile Name: 408+200..gszName: 6a. Sta. 408+200_Rapid Drawdown_Berm Re-size (Effective Stress)


Cohesion'(kPa)

Phi' (°)

Phi-B(°)

PiezometricLine

C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







1.279

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100445

450

455

460

465

470

475

445

450

455

460

465

470

475

KX05280503.7Highway 29. Bear Flat Cache Creek SegmentDate: 5/8/2019Last Edited By: Sinclair, KimFile Name: 408+200..gszName: 6b. Sta. 408+200_Rapid Drawdown_Berm Re-size (Undrained)


Cohesion'(kPa)

Phi'(°)

Phi-B(°)

PiezometricLine

Tau/SigmaRatio


C-Horizontal(kPa)

C-Vertical(kPa)

Phi-Horizontal(°)

Phi-Vertical(°)







Limitations



Project # KX05280503| August 14, 2019

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

Limitations

1. The work performed in the preparation of this report and the conclusions presented are subject

to the following:

a. The Standard Terms and Conditions which form a part of our Professional Services

Contract;

b. The Scope of Services;

c. Time and Budgetary limitations as described in our Contract; and

d. The Limitations stated herein.

2. No other warranties or representations, either expressed or implied, are made as to the

professional services provided under the terms of our Contract, or the conclusions presented.

3. The conclusions presented in this report were based, in part, on visual observations of the Site

and attendant structures. Our conclusions cannot and are not extended to include those portions

of the Site or structures, which are not reasonably available, in Wood’s opinion, for direct

observation.

4. Where testing was performed, it was carried out in accordance with the terms of our contract

providing for testing. Other substances, or different quantities of substances testing for, may be

present on-site and may be revealed by different or other testing not provided for in our contract.

5. The utilization of Wood’s services during the implementation of any remedial measures will allow

Wood to observe compliance with the conclusions and recommendations contained in the report.

Wood’s involvement will also allow for changes to be made as necessary to suit field conditions as

they are encountered.

6. This report is for the sole use of the party to whom it is addressed unless expressly stated

otherwise in the report or contract. Any use which any third party makes of the report, in whole or

the part, or any reliance thereon or decisions made based on any information or conclusions in

the report is the sole responsibility of such third party. Wood accepts no responsibility whatsoever

for damages or loss of any nature or kind suffered by any such third party as a result of actions

taken or not taken or decisions made in reliance on the report or anything set out therein.

7. This report is not to be given over to any third party for any purpose whatsoever without the

written permission of Wood.

8. Provided that the report is still reliable, and less than 12 months old, Wood will issue a third-party

reliance letter to parties that the client identifies in writing, upon payment of the then current fee

for such letters. All third parties relying on Wood’s report, by such reliance agree to be bound by

our proposal and Wood’s standard reliance letter. Wood’s standard reliance letter indicates that in

no event shall Wood be liable for any damages, howsoever arising, relating to third-party reliance

on Wood’s report. No reliance by any party is permitted without such agreement.

geotechnical assessment and design · 2019-08-19 · geotechnical assessment and design bear flat...

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