Mountview Proposed Dike Development Report Contact

May 19, 2020 | Revision 0

Submitted to the City of Fernie Prepared by McElhanney Ltd.

Contact Ryan Gibbard, P.Eng. Geotechnical Engineer 778-550-2002 [email protected]

Our file: 2441-01010-00

Address 1800 Willowbrook Drive Cranbrook, BC, V1C 7H9

Mountview Proposed Dike

Development

Geotechnical Assessment

Report

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Contents 1. Introduction .......................................................................................................................................... 1

2. Project and Geological Description ................................................................................................... 2

3. Reviewed Information and Documents ............................................................................................. 2

4. Field Assessment ................................................................................................................................ 3

5. Soil and Groundwater Conditions ...................................................................................................... 3

6. Evaluation and Analysis...................................................................................................................... 5

Soil Strength Parameters: ............................................................................................................................. 5

Soil Settlement Beneath Dike: ...................................................................................................................... 6

Permeability and seepage: ............................................................................................................................ 6

Surface erosion of dike slopes: ..................................................................................................................... 7

Surface erosion due to riverside stream action:............................................................................................ 7

Structures in and through the dike: ............................................................................................................... 7

Slope stability of dike: ................................................................................................................................... 8

Seismic Stability and Liquefaction: ............................................................................................................... 8

7. Recommendations ............................................................................................................................... 8

7.1. Site Preparation ................................................................................................................................ 9

7.2. Engineered Fill ................................................................................................................................ 10

7.3. Site Drainage................................................................................................................................... 11

7.4. Groundwater .................................................................................................................................... 11

7.5. Temporary Excavations .................................................................................................................. 11

7.6. Geosynthetics for Subgrade Improvements .................................................................................... 12

8. Design and Construction Review ..................................................................................................... 12

9. Closure ................................................................................................................................................ 13

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1. Introduction On behalf of the City of Fernie (the Client), McElhanney Ltd. (McElhanney) has prepared this technical

memo to provide a summary of the subsurface investigation and recommendations for the preliminary

geotechnical assessment completed for the proposed Mountview Dike Improvements Project (the

Project). The proposed project is located adjacent and just south of Mt McLean Drive, and east of Mt

Trinity Avenue at the south end of the Mountview residential area in Fernie, BC.

A test pit programme with field subgrade strength and permeameter testing was undertaken to provide

more qualitative shallow results than a borehole programme, and the Groundtech report (Ref. #4 below)

was relied upon in this study with nearby deep borehole data and testing for the existing Mountview dike.

The results of the geotechnical assessment, analysis, as well as preliminary recommendations on

geotechnical aspects of site development and dike design and construction, are provided in this technical

memo.

The study location is shown in Figure 1. Exact test pit locations are identified on the logs.

Figure 1 Project Site Location (with Test Pit locations)

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Authorization to proceed with the geotechnical investigation was provided by the Client, during the March

13, 2020 kickoff meeting. This report is subject to the appended Statement of Limitations – Geotechnical

Services.

McElhanney has completed this geotechnical assessment in general accordance with our proposal dated

February 26, 2020 (2441-91230-00). In conducting the geotechnical assessment and submitting this

memo, McElhanney has:

Completed a desktop review of the provided Groundtech Engineering Ltd. report entitled

“Geotechnical Site Investigation Report Fernie Dike, City of Fernie Flood Mitigation Plan” dated

December 21, 2018, as well as publicly available data;

Performed a field assessment including four (4) test pits with permeability and soil strength

testing, sampling and logging;

Completed laboratory testing on select soil samples; and,

Prepared this memo summarizing the results of the geotechnical assessment and preliminary geotechnical recommendations for the design and construction of the proposed development.

2. Project and Geological Description The proposed dike development (the Site) is located at the south end of the Mountview residential

subdivision in Fernie, BC. The site is bounded by Mt McLean Drive to the North, City sewerage facility to

the west, and low lying floodplain to the east and south. Based on preliminary design, the proposed

development comprises of an extension to the existing Mountview dike (reference the preliminary design

drawings completed by McElhanney (Ref. #1) as part of this project – not appended here). The proposed

section of dike will consist of an earthen granular setback dike.

The site generally slopes gently from north to south and is mostly covered with deciduous trees, low lying

water and vegetation.

Based on local experience and review of published surficial geology information, the site area is mapped

as glaciofluvial gravel and floodplain fluvial sand soil deposits. Underlying the surficial sand and gravel

soils, Groundtech encountered clayey silt at approximately 4.5m depth in this area (Ref. #4), extending

down to 15m, overlying hard soil conditions beneath, inferred as glacial till.

3. Reviewed Information and Documents The following documents have been referenced during the course of this assignment:

1. McElhanney – Mountview Dike 90% Design Drawings, 2020; 2. NHC – Fernie Flood Mitigation Plan, 2019; 3. McElhanney – Hill Road Dike Geotechnical Report, 2019; 4. Groundtech Engineering - Geotechnical Site Investigation Report Fernie Dike, City of Fernie

Flood Mitigation Plan, 2018; 5. McElhanney – West Fernie Dike Assessment, 2013; 6. NHC – West Fernie Bank Armouring, As-built Report, 2008;

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7. NHC – West Fernie Dike Improvements, Preliminary Design Final Report, 2010; 8. Kerr Wood Leidal – West Fernie Dike Improvement Project Phase 2, As-built Report, 2013; 9. Groundtech Engineering – Geotechnical Site Investigation Report, West Fernie Dike

Improvement Project Phase 2, 2012; 10. NHC – West Fernie Dike Improvement Project Phase 3-4, Tender Documents and Proposal,

2013; 11. Golder Associates – Seismic Design Guidelines for Dikes, Prepared for MFLNRO Safety Section,

2014; 12. BC Ministry of Forests, Lands and Natural Resource Operations – General Guidelines for Dike

Maintenance Act Approval for Pipe Crossings of Dikes, 2014 13. BC Ministry of Environment – General Guidelines, Comprehensive Geotechnical Investigation

and Design Report submitted in support of Dike Maintenance Act approval applications, 2011; 14. Province of BC – Dike Design and Construction Guide, 2003; 15. Province of British Columbia, L. Lacelle – BC Soil Survey Report No. 20, Map: Elko 82G/SW and

Cranbrook 82G/NW, 1990; 16. Google – Orthophoto and Aerial Mapping.

4. Field Assessment The geotechnical field assessment was carried out on April 23, 2020, which comprised of four (4) test

pits, with locations depicted on the Figure 1 above. The test pits were dug by Down to Earth Construction

of Sparwood, BC with an excavator to depths ranging from 1.2 to 2.6 mbgs (meters below ground

surface). Following completion of the test pits, they were backfilled with the excavated soil and nominally

compacted with the excavator bucket.

The subsurface conditions encountered at each test pit were observed and recorded by a McElhanney

representative. Detailed soil logs are attached. The soils observed in the field were classified in

accordance with the Modified Unified Classification System for Soils (MUSCS). DCPT and permeameter

field tests were conducted in the test pits where possible, and reports are provided in Attachment C. The

test pit locations were surveyed after completion.

Upon completion of the field program, select soil samples were submitted to Artech Consulting Ltd. for

index testing including moisture content and sieve analysis. The laboratory testing results are

summarized on the soil logs and the laboratory test reports are provided in Attachment C.

5. Soil and Groundwater Conditions A summary of the subsurface conditions observed at the test pit locations are provided in Table 1. A

summary of the gradation and moisture content testing is presented in Table 2. The detailed soil logs are

included in Attachment B. All depths provided in this section are referenced from the existing ground

surface at the time of the field investigation.

There were several materials encountered within the depth of exploration: granular fills; topsoil; silt and

sand; and native sandy gravels.

Groundwater was encountered in each test pit, and was a limiting factor in achieving greater depths.

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Table 1 Summary of Test Pits

Test Location

End of Hole

(mbgs)

Soil Unit (mbgs) Groundwater/Seepage Depth (mbgs) Granular

Fills Topsoil Silt and

Sand Native Sandy Gravel

TP20-01 2.6 0-2.45+ N/E N/E N/E 0.9

TP20-02 1.2 0.1-1.2+ 0-0.1 N/E N/E 0.8

TP20-03 2.45 N/E 0-0.1 0.1-0.6 0.6-2.45+ 1.7

TP20-04 2.0 N/E 0-0.1 0.1-1.1 1.1-2.0+ 2.0

Notes: N/E not encountered

Granular Fills: TP20-01 and TP20-02 were excavated in areas of fill:

HORIZON #1A: YARD FILL ZONE: TP20-01 is located in a built up area of previously placed

yard fills consisting of silty gravels, debris (concrete, steel, wood and asphalt), and clean gravel

fills.

HORIZON #1B: DIKE FILL ZONE: TP20-02 is located on clean granular fill that was previously

placed for the construction of the adjacent sewerage facility, and the Mountview Dike feature (as

investigated by Groundtech – Ref. #4).

HORIZON #2: Topsoil: The entirety of the natural site is overlain by a thin topsoil layer that was 0.1m

thick.

HORIZON #3: Silt and Sand: a fluvial deposit of low plastic silt and medium to fine sand exist over the

site beneath the topsoil. These soils exist in depths ranging from 0.5 to 1.0mbgs. The silt was firm where

it was encountered at or below groundwater, and DCP testing indicated a stiff consistency in the soil

above groundwater.

HORIZON #4: Sandy Gravel: compact glaciofluvial sandy gravel with trace to some fines was

encountered underlying the Silt and Sand layer. These soils begin at depths ranging from 0.6 to 1.1

mbgs, and extend down beyond the test pit limits to an approximate depth of 4.5 mbgs (Ref. #4).

Table 2 Summary of Gradation Results

Test Location Sample Depth (mbgs)

Moisture Content (%)

Gradation

Soil Classification

(MUSCS) Gravel Sand Fines (Silt and

Clay)

TP20-02 S1 (0.6) 4.1 80 18 2 GP

TP20-03 S1 (0.3) 27 0 42 58 ML/SM

TP20-03 S2 (0.8) 7.5 70 27 3 GP

TP20-04 S1 (2.0) N/A 60 32 8 GP

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Groundwater: Groundwater was observed in all test pits at the time of excavation as shown in

Table 1. Note that groundwater monitoring instrumentation was not installed as part of the current scope

of work. Standing water was observed nearby and adjacent around the site.

6. Evaluation and Analysis For the purposes of the below evaluation and analysis of the existing site conditions and soils for

placement of the proposed dike, there are a few considerations and design parameters:

1. The gravel yard fill of Horizon #1A in the location of TP20-01 contains significant construction

debris, such as concrete, asphalt, steel and wood. As such, this layer is considered unsuitable

for dike material or subgrade, and must be stripped from within the dike construction footprint

down through any organic layer(s) and topsoil to the suitable native Horizon #3 or #4 soils. Clean

pockets of suitable granular material were observed, and could partially be recovered, stockpiled

and re-used within the project.

2. The clean granular fill of Horizon #1B in the location of TP20-02 is consistent with the nearby

granular Mountview dike fills observed by Groundtech in 2018 (Ref. #4). These previously placed

and compacted gravels are suitable subgrade for dike placement, provided that the top 0.3m is

stripped and the surface compacted in accordance with this report.

SOIL STRENGTH PARAMETERS:

Soil strength parameters for the near-surface soils were approximated based on field testing at the time of

our investigation. A summary of this analysis is presented in Table 3:

Table 3 Summary of Field Strength Testing and Approximation of Ultimate Soil Bearing values for the Dike

Test Location

Depth (mbgs)

Soil Horizon CBR (%)

Shear Strength (Torvane)

(kPa)

Estimated Internal Soil

Angle of Friction (°)

Estimated Ultimate Soil Bearing (kPa)

TP20-01 0.5 #1A – Yard Fill 56 n/a 42 580

TP20-02 0.6 #1B – Clean Gravel Fill 26 n/a 36 280

TP20-03 0.5 #3 – Sand/Silt 8 50 29 100

TP20-03 0.8 #4 – Sandy Gravel 42 n/a 40 450

Notes: n/a = not applicable

Significantly, the site soils identified all exhibit moderate to strong bearing strength characteristics. Based

on a pseudo footing width typical with the proposed dike, and allowing for some variation of widths, the

Factor of Safety (FoS) for the bearing pressures is conservatively estimated at least 2.5 on the weakest

soil layer observed (sand/silt). Based on this analysis, we confirm that the observed native or clean

granular fill subgrade soils should adequately support the loading of the proposed raised dike feature.

Given the known subsurface and underlying conditions, we confirm that there are no known soil strength

conditions that would impact the dike design.

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SOIL SETTLEMENT BENEATH DIKE:

Settlement, based on the assumed loading, is approximated to be less than 20mm post construction,

provided the dike is constructed appropriately and in accordance with the recommendations below.

Consolidation settlement of the deeper clayey silt soils was considered utilizing the consolidation testing

undertaken by Golder for the Groundtech report (Ref. #4), and based on the known depth was

conservatively calculated to be a maximum of 10mm.

PERMEABILITY AND SEEPAGE:

Field permeability testing was conducted where possible, and a calculated hydraulic conductivity, or

coefficient of permeability (Kfs) was determined. For the underlying gravel layer where testing was not

feasible, an estimated value is provided. See Table 4 for a summary of this analysis:

Table 4 Summary of Field and Calculated Approximation of Permeability

Location Depth (mbgs)

Soil Horizon Permeability (Kfs)

(cm/sec)

Methodology

TP20-01 0.5 Gravel Yard Fill 3.85 x 10-4 Permeameter

TP20-02 0.6 Gravel Dike Fill 6.54 x 10-3 Permeameter

TP20-03 0.25 Sand/Silt 9.31 x 10-4 Permeameter

TP20-03 0.8 Sandy Gravel 5.0 x 10-3 Hazen formula

Note that, to varying degrees, all soils observed are considered to be moderately permeable. It is

possible that a deep cutoff trench or grout curtain cutoff wall filled with low permeability soil or grout could

be installed beneath the dike to limit seepage in the foundation soils beneath the dike; however, the

practicality of this is considered very low, as the high groundwater table would necessitate significant

dewatering activities, and the trench would need to extend down to the clay layer at a depth of

approximately 4.5m. Also of consideration is that the adjacent Mountview dike, and other nearby dikes,

do not have a groundwater seepage cutoff. Another risk of installing the cutoff is that the groundwater

regime was previously interpreted to flow from the mountain side down to the river (Ref. #4), and

therefore cutting off the flow of groundwater could possibly contribute to flooding on the upland side of

the dike. It is our opinion that a cutoff trench is very cost prohibitive and may cause unintended negative

impacts. Further hydrogeological study is warranted to determine this; but for the purposes of this report

a cutoff trench could be added at a later date if deemed necessary.

Seepage analysis of a typical dike section, with underlying native soils as identified here, was completed.

The proposed dike and the underlying foundation soils are considered sufficiently permeable to allow the

phreatic surface through the dike structure to adjust with the changing flood water surface, and remain

intact.

We recommend the use of lower permeable granular soils in the construction of the dike to reduce

seepage through the structure. See below for detail.

Uplift is not considered to be a concern given the soils present at this site.

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Since there is no dam core, there are no soil gradation compatibility concerns. Piping failures through

preferential paths can be mitigated by preventing the growth of trees on and near the dam, as well as

monitoring and removing animal burrows and dens on and around the dike to prevent preferential flow

paths from developing on the dike. If paths are observed during routine inspections over the service life of

the dam, a geotechnical engineer should be contacted for input.

SURFACE EROSION OF DIKE SLOPES:

The proposed section of dike will be constructed out of a sand and gravel product with 15-30% silt and

clay to reduce the permeability of the dike. In order to minimize surficial erosion of the dike surface, it is

recommended that the maximum slope angle is to be 2.5:1, and that the dike be compacted to a

minimum of 98% Standard Proctor Maximum Dry Density (SPMDD) in maximum 250mm lifts, and within

3% of the optimum moisture content as derived from the ASTM D-698 Moisture-Density relationship

(Proctor test). The dike slopes will be topsoiled and seeded with a hardy, dense grass seed mixture,

suitable for mitigating any erosion due to rainfall runoff on the dike slopes.

SURFACE EROSION DUE TO RIVERSIDE STREAM ACTION:

The dike is setback from the Elk River by 50-250 m, and a densely treed area runs between the river and

the proposed dike. Based on modelling data from the NHC report (Ref. #2) and our understanding of the

local river hydraulics, this vegetation and setback distance will significantly reduce flood velocities at the

dike. The NHC report (Ref. #2) does not recommend riprap erosion protection for the riverside dike slope,

and no riprap erosion protection is proposed in McElhanney’s design. The grassed riverside slope is

expected to be sufficient to resist the low flood velocities expected against the dike.

STRUCTURES IN AND THROUGH THE DIKE:

It is understood that the design may include a culvert feature through the dike structure. For this

situation, in order to prevent the migration of soils along the path of the pipe surface in accordance with

the Ministry Pipe Crossings of Dikes guidelines (Ref. #11), the following is recommended:

Landside Drainage Fills be installed around the culvert for the first 1/3 of the length of the culvert

length through the dike;

The Drainage Fills shall consist of fine Drain rock backfill (see specified gradation in Table 5

below);

The dike fill shall be placed to 200mm in elevation above the top of the culvert elevation. The

culvert shall be cut down to a depth 200mm below the bottom of the pipe;

A medium strength nonwoven geotextile fabric (see specification in Table 6 below) shall be

placed in one piece longitudinally along the section of drainage fill, covering the bottom and sides,

with sufficient material to cover over top and overlap at least 0.5m;

A 200mm lift of the drainrock material be placed and compacted along the base as bedding;

The culvert pipe be installed, and backfilled and compacted along the sides in 200mm lifts;

A 200mm lift of the drainrock material cap over the pipe and be compacted. The geotextile shall

fold over this material with 0.5m overlap;

At the end of the Drainage Fill within the dike, the geotextile fabric must fold back and be tightly

sealed/taped to the sides of the culvert pipe so as to prevent migration of fines. If this seal cannot

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be achieved, then a bedding sand filter (meeting MMCD bedding sand specifications) at least

0.5m wide must be included at the transition between the common dike fill and the Drainage Fill.

SLOPE STABILITY OF DIKE:

Rocscience Slide (V6.0) was used to evaluate stability of a typical cross section of the dike given the

native foundation soils observed.

Landside stability due to seepage was analyzed. This is considered a steady state seepage condition,

with full saturation of the dike soils. Analysis shows that a dike side slope of 2.5:1 or less is stable with a

Factor of Safety (FOS) greater than 1.5. with the condition that the water level height is less than the top

of the 3m or less height dike structure.

Riverside stability due to draw down was also considered. Given the anticipated moderately well draining

permeabilities of the dike and foundation soils, the materials will provide sufficient drainage given the

anticipated slower drawdown of the river such that elevated pore pressures will not develop and cause

instability (Ref. #4).

Given the anticipated depth to weaker soils of 4.5m (Ref. #4), the limiting stability factor in the dike design

is in fact the quality and slope angle of the dike fill itself. Given such, the stability of the dike in the above

scenarios is considered sufficient provided that the recommendations in this report are followed.

SEISMIC STABILITY AND LIQUEFACTION:

Following the analysis completed by Groundtech for the same soils in 2018 (Ref. #4) it is agreed and

corroborated that, given:

the very low likelihood of seismic activity at this location,

the low probability of liquefaction of the soils of the Fernie floodplain, and

the quality of near surface and surface materials at this site,

that no additional mitigation works are required for this section of dike.

7. Recommendations The geotechnical recommendations provided in this report are based on the understanding of the

proposed dike design and site location as described above. It is recommended that if any changes to the

proposed works or site location are made to what is designed and reviewed for this report that the

undersigned be given the opportunity to assess the applicability of the recommendations provided herein

and/or recommendations for further geotechnical study be provided if required. A geotechnical engineer

should provide additional recommendations if conditions during construction are different than reported

herein.

Based on our project understanding and the findings of this geotechnical assessment, the site appears to

be suitable for dike development from a geotechnical perspective with consideration of the

recommendations and discussion provided in this report. The following sections provide preliminary

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discussion and recommendations as input for planning and preliminary design based on the current

understanding of the proposed dike improvement project.

7.1. SITE PREPARATION

Based on the test pit observations, the depth to suitable subgrade soils was 0.1m in native soil and dike

fill locations (Test Pits 20-02, 20-03 and 20-04). In the yard fill area, it is estimated that up to 3.0m of

variable granular fill containing debris will need to be removed down to inorganic, strong suitable native

subgrade similar to the native soil locations. Any soft/loose and/or otherwise unsuitable subgrade areas

otherwise identified at the time of construction should be sub-excavated and replaced with material

meeting the specifications for compacted Engineered Fill (Section 5.2) to design sub-grade elevation for

dike base and other grade-supported portions of the development.

The following general recommendations are provided for subgrade preparation of grade-supported, load-

bearing structures (such as the dike):

Remove any existing vegetation, organic soil, deleterious fill soils/materials, soft/wet soils, and

debris materials underlying load-bearing structures to expose the underlying compact to dense

and/or firm to stiff native inorganic soil subgrade. Note that the subsurface conditions may vary

across the site given the unknown development history and removal of unsuitable soils may be

required to depths beyond design subgrade depths in some areas not specifically tested.

All prepared subgrades should be inspected in the field by a Geotechnical Engineer or their

representative to confirm that the subgrade conditions are consistent with the design conditions

assumed in this report. Soil subgrade should be proof-rolled using either a fully loaded tandem

truck or a single-drum compaction roller under the direction of the Geotechnical Engineer or their

representative to identify any loose/soft areas before placement of any Engineered Fill.

Soft, loose, wet, and/or otherwise unsuitable subgrade surfaces can be repaired by sub-

excavation and replacement with Engineered Fill compacted to 98% Standard Proctor Maximum

Dry Density (SPMDD) unless otherwise specified in this report (see Section 7.2).

Subject to field review at the time of construction, approved subgrade of any sub-excavations

within the proposed development limits should be backfilled to design subgrade elevation with

approved fill material in accordance with the material selection, placement and compaction

specifications for Engineered Fill, as defined in Section 7.2.

General site grading fills, if required to raise local site grades, should consist of approved common fill

comprising clean inorganic granular materials or an approve alternative from approved local or imported

sources. Subject to surface grading, drainage and settlement tolerances required for site grading design,

common fill materials may be placed in uniform layers not exceeding 300 mm thickness and compacted

to a minimum of 95% Standard Proctor Maximum Dry Density (SPMDD) unless otherwise specified in this

report.

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7.2. ENGINEERED FILL

Any fill soil placed to support structural elements, including the dike, of the development shall be

considered Engineered Fill. Engineered Fill should consist of well-graded sand and gravel with less than

5% fines (material passing the 0.075 mm sieve) where appropriate, or for common dike fill be a sand and

gravel product with 15-30% fines and a maximum aggregate size not exceeding 75 mm. Any granular

materials proposed for use as Engineered Fill should be tested and approved by the Geotechnical

Engineer before placement. See Table 3 for recommended gradations for granular dike fill, granular sub-

base (well graded gravel) and drain rock materials.

Table 5 Material Gradations – Granular Dike Fill, Granular Sub-Base and Drain Rock

Sieve Size (mm)

Granular Dike Fill Crushed Granular Sub-Base Drain Rock

Percent passing (%)

75 100 100 -

50 - -

38 - 60-100

25 - - 100

19 - 35-80 25-100

12.5 - - -

9.5 - 26-60 -

4.75 30-60 20-40 0-5

2.36 - 15-30 -

1.18 20-45 - -

0.6 - 5-15 -

0.3 - 3-10 -

0.075 15-30 0-5 0-1

Sieve analysis completed on samples obtained from the assessment indicated that the granular soils

encountered on site are not suitable for used as dike fill as they contain less than 15% fines (material

passing the 75 micron sieve).

Recommendations for placement of Engineered Fill are summarized as follows:

Engineered Fill should be placed on prepared subgrade surfaces following the recommendations

in Section 7.1 and approved by a Geotechnical Engineer or their representative before

placement.

Engineered Fill used to support dikes, utilities, or any other component that may be settlement-

sensitive should be compacted to a minimum of 98% standard Proctor Maximum Dry Density

(SPMDD), with the upper 300 mm compacted to 100% SPMDD. In landscaped and non-dike fill

areas or other areas where the risk of differential and/or total settlement greater than 25 mm may

be acceptable, Engineered Fill may be compacted to a minimum of 95% SPMDD.

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Engineered Fill should be placed in horizontal lifts not exceeding 250mm vertical loose thickness,

dependant on the type of compaction equipment used. Engineered Fill should be placed at

moisture conditions conducive to achieving compaction specifications (typically within 3% of the

optimum moisture content) as determined by a Standard Proctor Moisture-Density Test (ASTM

D698).

Any permanent dike slopes should have a maximum slope angle of 2.5H:1V for Engineered Fill

and should be adequately protected from erosion.

Continuous Quality Control (QC) compaction testing and construction reviews should be

performed by the Geotechnical Engineer’s representative or a qualified testing agency during

placement of all Engineered Fill to verify compliance with the above recommendations.

7.3. SITE DRAINAGE

Positive surface drainage should be maintained away from the development areas in all directions,

considering existing infrastructure adjacent to the proposed development. Surface drainage of all

developed areas should be maintained with minimum 2% cross-slope recommended, particularly away

from structures and dikes.

7.4. GROUNDWATER

Groundwater was encountered at depths of 0.8 to 2.0m at all test pits at time of excavation. It is likely

that groundwater seepage will be encountered during construction. The groundwater should not be

permitted to collect in the bottom of the excavations during construction and a contingency plan should be

made to pump out or drain excavations with sump pumps and to divert water away from the excavation. If

significant groundwater seepage or softening subgrade soils are encountered the geotechnical engineer

should be contacted to review.

7.5. TEMPORARY EXCAVATIONS

To protect existing utilities and adjacent infrastructure during construction, and to allow for safe worker

access, temporary excavation slopes shall be constructed as per most current applicable Worksafe BC

regulations.

For planning purposes, it is recommended that temporary excavation slopes be sloped no steeper than

1.5 Horizontal to 1 Vertical (1.5H:1V) within areas of fined grained soils or fine-grained sands. Flatter

slopes or other temporary support measures may be required if significant seepage or groundwater inflow

conditions are encountered. Steeper temporary slopes of up to 1.0H:1.0V may be considered in shallow

excavations based on conditions encountered during construction. If steeper slopes or slopes greater

than 6 m in height are to be considered, or poor/saturated soil conditions or significant seepage is

encountered, a Geotechnical Engineer should be consulted to review.

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7.6. GEOSYNTHETICS FOR SUBGRADE IMPROVEMENTS

A geotextile (or possibly geogrid) may be required to improve compaction over soft/wet subgrade

locations as determined by the geotechnical engineer or their representative during subgrade

assessment. It is also recommended as a filter between culvert bedding backfill and dike fill (see above).

A medium weight non-woven geotextile is specified with the properties indicated in Table 6 below.

Table 6 Specifications for Non-woven Geotextile – Moderate Survivability (1)

Property (2) ASTM

Test Unit Value

Grab Tensile Strength D4632 N 700(3)

Trapezoid Tear Strength D4533 N 250

CBR Puncture Strength D6241 N 1,400

Permittivity D4491 sec-1 0.02

Apparent Opening Size D4751 mm 0.60

Ultraviolet Stability (4) D 7238 % strength retained at

500 hours

70

Notes: 1. GRI GT13(a) – ASTM Version, Revision 4, June 20, 2017. Geosynthetic Institute2. All values are minimum average roll values (MARV) except AOS which is a maximum average roll value and

UV stability which is a minimum average value.3. Elongation >50%.4. ‘Evaluation to be on 50 mm strip tensile specimens after 500 hours exposure.

The non-woven geotextile should be placed above the prepared subgrade as per the manufacturers’

specifications.

8. Design and Construction ReviewThe recommendations provided coincide with the 90% design drawings and stated project assumptions

above in mind, and it is recommended that any further alterations to the design be reviewed by a

geotechnical engineer to verify that the geotechnical recommendations and what further geotechnical

assessment may be required for final design and construction.

To issue applicable Dike Maintenance Act letters of assurance and/or construction QA/QC letters, all

backfill and Engineered Fill subgrade shall be reviewed by the geotechnical engineer or their

representative as specified in this report. McElhanney can provide QA material testing services during

construction if requested.

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9. Closure We trust that this information is sufficient for your present needs. Should you have any questions or

require additional information, please do not hesitate to contact the author of the document.

Sincerely,

McElhanney Ltd.

Prepared By:

Ryan Gibbard, P.Eng. Senior Geotechnical Engineer [email protected] 778-550-2002

Reviewed By:

Melissa Chappel, P.Eng Karen Prezelj, P.Eng Geotechnical Engineer Project Manager, Civil Engineer [email protected] [email protected]

Attachments:

Statement of Limitations – Geotechnical Services

Attachment A – Test Pit Logs

Attachment B – Field Test Results

Attachment C – Laboratory Test Reports

Attachment D – Slide Analysis Printouts

Page | 14

STATEMENT OF LIMITATIONS –

GEOTECHNICAL SERVICES

Statement of Limitations – Geotechnical Services

Last Updated on: 2019-05-08

Use of this Report. This report was prepared by McElhanney Ltd. ("McElhanney") for the particular site, design objective, development and purpose (the “Project”) described in this report and for the exclusive use of the client identified in this report (the “Client”). The data, interpretations and recommendations pertain to the Project and are not applicable to any other project or site location and this report may not be reproduced, used or relied upon, in whole or in part, by a party other than the Client and Building Authority, without the prior written consent of McElhanney. The Client may provide copies of this report to its affiliates, contractors, subcontractors and regulatory authorities for use in relation to and in connection with the Project provided that any reliance, unauthorized use, and/or decisions made based on the information contained within this report are at the sole risk of such parties. McElhanney will not be responsible for the use of this report on projects other than the Project, where this report or the contents hereof have been modified without McElhanney’s consent, to the extent that the content is in the nature of an opinion, and if the report is preliminary or draft. This is a technical report and is not a legal representation or interpretation of laws, rules, regulations, or policies of governmental agencies. The professional services retained for this Project include only the geotechnical aspects of the subsurface conditions at the site, unless otherwise specifically stated and identified in this report. In particular, environmental conditions such as surface and subsurface contamination are outside the scope of this report.

Standard of Care and Disclaimer of Warranties. This study and report have been prepared in accordance with generally accepted engineering and scientific judgments, principles and practices. McElhanney expressly disclaims any and all warranties in connection with this report including, without limitation, any warranty that this report and the associated site review work has uncovered all potential geotechnical liabilities associated with the subject property.

Effect of Changes. All evaluations and conclusions stated in this report are based on facts, observations, site-specific details, legislation and regulations as they existed at the time of the site assessment. Some conditions are subject to change over time and the Client recognizes that the passage of time, natural occurrences, and direct or indirect human intervention at or near the site may substantially alter such evaluations and conclusions. Construction activities can significantly alter soil, rock and other geologic conditions on the site. McElhanney should be requested to re-evaluate the conclusions of this report and to provide amendments as required prior to any reliance upon the information presented herein upon any of the following events: a) any changes (or possible changes) as to the site, purpose, or development plans upon which this report was based, b) any changes to applicable laws subsequent to the issuance of the report, c) new information is discovered in the future during site excavations, construction, building demolition or other activities, or d) additional subsurface assessments or testing conducted by others.

Subsurface Risks. Soil, rock and groundwater data were collected in general accordance with the standards and methods described in the document. The classification and identification of soils, rocks and geologic formations was based on commonly accepted methods employed in the practice of geotechnical engineering and related disciplines. Interpretations of groundwater levels and flow direction are based on water level observations at selected test hole locations and are expected to fluctuate. Observations at test holes indicate the approximate subsurface conditions at those locations only. Subsurface conditions between test holes were based, by necessity, on judgement and assumptions of what exists between the actual locations sampled, and may vary significantly from actual site conditions and all persons making use of this report should be aware of, and accept, this risk. Even a comprehensive sampling and testing program, implemented in accordance with appropriate equipment by experienced personnel, may fail to detect all or certain conditions.

Information from Client and Third Parties. McElhanney has relied in good faith on information provided by the Client and third parties noted in this report and has assumed such information to be accurate, complete, reliable, non-fringing, and fit for the intended purpose without independent verification. McElhanney accepts no responsibility for any deficiency, misstatements or inaccuracy contained in this report as a result of omissions or errors in information provided by third parties or for omissions, misstatements or fraudulent acts of persons interviewed.

Underground Utilities and Damages. In the performance of the services, McElhanney has taken reasonable precautions to avoid damage or injury to subterranean structures or utilities. Subsurface sampling may result in unavoidable contamination of certain subsurface areas not known to be previously contaminated such as, but not limited to, a geologic formation, the groundwater or other hydrous body. McElhanney will adhere to an appropriate standard of care during the conduct of any subsurface sampling.

Independent Judgments. McElhanney will not be responsible for the independent conclusions, interpretations, interpolations and/or decisions of the Client, or others, who may come into possession of this report, or any part thereof. This restriction of liability includes decisions made to purchase, finance or sell land or with respect to public offerings for the sale of securities.

Construction. The subsurface information contained in this report were obtained for the owner’s information and design. The extent and detail of assessments necessary to determine all relevant conditions that may affect construction costs would normally be greater than the assessments carried out for this report. Accordingly, a contingency fund to allow for the possibility of variations of subsurface conditions should be included in the construction budget to cover costs associated with modifications of the design and construction procedures resulting from conditions that vary from the assumptions in this report. If during construction, subsurface conditions are found to be other than those described in this report, McElhanney is to be notified and may alter or modify the geotechnical report recommendations. If McElhanney is not retained to provide services during construction, then McElhanney is not responsible for confirming or recording that subsurface conditions do not materially differ from those interpreted conditions contained in this report or for confirming or recording that construction activities have not adversely affected subsurface conditions or the recommendations contained in this report.

Page | 15

APPENDIX A – TEST PIT LOGS

0.45m

2.6m

DCPT and PermeametercompletedCBR = 56%k(fs) =4.0 x 10^-4cm/s

[FILL] SAND and gravel, trace fines, inferredcompact, dark bronw, damp, occasionalasphalt, concrete and steel debris

Sandy GRAVEL, trace fines, damp,compact, medium brown, occasional cobble

- Significant water entering- Sidewalls unstable and collapsing- Backfilled with cuttings with nominalcompaction upon completion

Fill

GP

L#-Lab SampleW-Wash(mud return)

Elevation: 987.87 m

987

986

985

984

983

982

981

980

979

978

Marcus BrownPrepared by:

Logged by: RG Reviewed by: RG

SO

IL S

YM

BO

L

RE

CO

VE

RY

(%

)

SA

MP

LE N

O

SA

MP

LE T

YP

E1

2

3

4

5

6

7

8

9

Operator:

CLA

SSIF

ICAT

ION

Location: Mt. McLean Street Fernie, BC

Date(s) Drilled: April 23, 2020

Coordinates Surveyed 05/01/2020

Project: Mountview Dike

ELE

VA

TIO

N (

m)

1

2

3

4

5

6

7

8

9

LegendSample Type:

S-SplitSpoon

O-Odex(air rotary)

T-ShelbyTube

C-CoreA-Auger G-Grab V-Vane

SOILDESCRIPTION

00

Page 1 of 1

DE

PT

H (

m)

DR

ILLI

NG

DE

TA

ILS

Alignment:

10

0

Northing/Easting: 5483574.4483 , 639638.16

Final Depth of Hole: 2.6 mDepth to Top of Rock:

Station/Offset:

Excavating Company:

2441-01010-00

TEST PIT LOG

Datum: 11 U

COMMENTS

Excavator: Volvo EC160DL

Test Pit #: TP-01M

CE

LHA

NN

EY

SO

IL L

OG

244

1-01

010-

00 M

OU

NT

VIE

W D

YK

E S

OIL

LO

GS

.GP

J M

CE

LHA

NN

EY

TE

MP

LAT

E R

EV

2.G

DT

5/1

9/2

0

DYNAMIC CONE (BLOWS/300 mm)

W % W %L

20 40 60 80P W%

SPT "N" (BLOWS/300 mm) Natural Vane (KPa) Remold Vane (KPa)

100 200 300 400 Pocket Penetrometer Shear Strength (kPa)

Water-0.9m

0.1m

1.2m

SA1

2 DCPT's and Permeametercompleted 0.6m bgsCBR = 36% and 43%k(fs) = 6.5 x 10^-3cm/s

Organics and topsoil

[FILL] sandy GRAVEL, trace fines, loose tocompact, damp, light grey

- Unable to excavate beyond due to holesloughing in- Backfilled with cuttings with nominalcompaction upon completion

TS

GPSieve (Sa#SA1)Gravel:80%Sand:18%Fines:2%


Elevation: 988.05 m

987

986

985

984

983

982

981

980

979



SO

IL S

YM

BO

L

RE

CO

VE

RY

(%

)

SA

MP

LE N

O

SA

MP

LE T

YP

E1

2

3

4

5

6

7

8

9

Operator:

CLA

SSIF

ICAT

ION





ELE

VA

TIO

N (

m)

1

2

3

4

5

6

7

8

9

LegendSample Type:

S-SplitSpoon

O-Odex(air rotary)

T-ShelbyTube


SOILDESCRIPTION

00

Page 1 of 1

DE

PT

H (

m)

DR

ILLI

NG

DE

TA

ILS

Alignment:

10

0



Station/Offset:

Excavating Company:

2441-01010-00

TEST PIT LOG

Datum: 11 U

COMMENTS


Test Pit #: TP-02M

CE

LHA

NN

EY

SO

IL L

OG

244

1-01

010-

00 M

OU

NT

VIE

W D

YK

E S

OIL

LO

GS

.GP

J M

CE

LHA

NN

EY

TE

MP

LAT

E R

EV

2.G

DT

5/1

9/2

0


W % W %L

20 40 60 80P W%



Water-0.8m4.1

0.1m

0.6m

2.45m

SA1

SA2

Permeameter completed k(fs) =9.3 x 10-4cm/s

Native organic forest floor, silty LOAM

SILT and sand, trace clay, firm, lowplasticity, damp to moist, medium brown

Sandy GRAVEL, trace fines, compact, wet,brown to grey, occasional cobbles andboulders up to 300mm

- Significant water entering excavation- Backfilled with cuttings with nominalcompaction upon completion

TS

ML

GP

Sieve (Sa#SA1)Gravel:0%Sand:42%Fines:58%



Elevation: 987.53 m

987

986

985

984

983

982

981

980

979

978



SO

IL S

YM

BO

L

RE

CO

VE

RY

(%

)

SA

MP

LE N

O

SA

MP

LE T

YP

E1

2

3

4

5

6

7

8

9

Operator:

CLA

SSIF

ICAT

ION





ELE

VA

TIO

N (

m)

1

2

3

4

5

6

7

8

9

LegendSample Type:

S-SplitSpoon

O-Odex(air rotary)

T-ShelbyTube


SOILDESCRIPTION

00

Page 1 of 1

DE

PT

H (

m)

DR

ILLI

NG

DE

TA

ILS

Alignment:

10

0



Station/Offset:

Excavating Company:

2441-01010-00

TEST PIT LOG

Datum: 11 U

COMMENTS


Test Pit #: TP-03M

CE

LHA

NN

EY

SO

IL L

OG

244

1-01

010-

00 M

OU

NT

VIE

W D

YK

E S

OIL

LO

GS

.GP

J M

CE

LHA

NN

EY

TE

MP

LAT

E R

EV

2.G

DT

5/1

9/2

0


W % W %L

20 40 60 80P W%



Water-1.7m

27

7.5

0.1m

1.1m

2.0mSA1

Native organic forest floor, silty LOAM

SAND (medium ot fine) and silt, trace clay,firm, low plasticity, damp to moist, mediumbrown

Sandy GRAVEL, trace silt, compact, damp,brown, occasional organics

- Excavation terminated when groundwaterencountered- Backfilled with cuttings with nominalcompaction upon completion

TS

SM

GP



Elevation: 987.3 m

987

986

985

984

983

982

981

980

979

978


Logged by: MB Reviewed by: RG

SO

IL S

YM

BO

L

RE

CO

VE

RY

(%

)

SA

MP

LE N

O

SA

MP

LE T

YP

E1

2

3

4

5

6

7

8

9

Operator:

CLA

SSIF

ICAT

ION





ELE

VA

TIO

N (

m)

1

2

3

4

5

6

7

8

9

LegendSample Type:

S-SplitSpoon

O-Odex(air rotary)

T-ShelbyTube


SOILDESCRIPTION

00

Page 1 of 1

DE

PT

H (

m)

DR

ILLI

NG

DE

TA

ILS

Alignment:

10

0



Station/Offset:

Excavating Company:

2441-01010-00

TEST PIT LOG

Datum: 11 U

COMMENTS


Test Pit #: TP-04M

CE

LHA

NN

EY

SO

IL L

OG

244

1-01

010-

00 M

OU

NT

VIE

W D

YK

E S

OIL

LO

GS

.GP

J M

CE

LHA

NN

EY

TE

MP

LAT

E R

EV

2.G

DT

5/1

9/2

0


W % W %L

20 40 60 80P W%



Water-2.0m 3.5

Page | 16

APPENDIX B – FIELD TEST RESULTS

Client: Job #:

Location: Tested By: RG/KP Date:

Weather: Auger Hole (AH)#: 1 AH Location:

AH Depth: AH Diameter (cm): 8 AH Radius (cm):

Permeameter ID#: Height of Air Hole (H): 20 Perm ID =

Time of Day Total Elapsed

Time

min

Interim time

min

Water Level Reading

mm

Drop in

Level

mm

Rate of Fall

mm/min

Test 1 0 0 640

0.5 0.5 375 265 530.0

1 1 320 55 55.0

2 1 313 7 7.0

3 1 308 5 5.0

4 1 303 5 5.0

5 1 298 5 5.0

10 5 275 23 4.6

5 Flow Rate (mL/min)=

C (from chart)= 1.7 Q (mL/min)= 40 a2(cm2)= 25 H/a= 5

α*=f(soil)= 0.36 2πH

2= 2513 πa

2C= 85 2πH/∝

*= 349

2947 0.023074

K(fs) cm/day = 33.23 K(fs) m/day = 0.33

Permeameter Test

Test Results

Mountview Dike

Remarks or Observations

1

2441-01010-00

4/23/2020

TP20-01 0.5m bgs

4

10.15492

40

[2πH2 + πa

2C + 2πH/∝

*] in cm

2 = K(fs) = CQ/[2πH

2 + πa

2C + 2πH/∝

*] cm/min =

Reference: Mooers, J.D., and D.H. Waller, 1993 ON-Site Wastewater Disposal in Nova Scotia, Final Report, On-Site Wastewater

Research Program Phase 2 1990-1993. Technical University of Nova Scotia

Comments:

Mt. McLean Street

19°C

25

Note : K(sat) is larger than K(fs)

Stable rate of fall (mm/min)=

Client: Job #:






Time

min

Interim time

min

Water Level Reading

mm

Drop in

Level

mm

Rate of Fall

mm/min

Test 1 0 0 510

0.5 0.5 170 340 680.0

1 1 50 120 120.0

2 1 0 50 50.0

85 Flow Rate (mL/min)=



2= 2513 πa

2C= 85 2πH/∝

*= 349

2947 0.392263


Permeameter Test

Test Results

Mountview Dike


1

2441-01010-00

4/23/2020

TP20-02 0.45m bgs

4

10.15492

680

[2πH2 + πa

2C + 2πH/∝

*] in cm

2 = K(fs) = CQ/[2πH

2 + πa

2C + 2πH/∝

*] cm/min =



Comments:

Mt. McLean Street

19°C

25



Client: Job #:






Time

min

Interim time

min

Water Level Reading

mm

Drop in

Level

mm

Rate of Fall

mm/min

Test 1 0 0 558

0.5 0.5 365 193 386.0

1 1 357 8 8.0

2 1 344 13 13.0

3 1 328 16 16.0

4 1 312 16 16.0

5 1 295 17 17.0

15.5 Flow Rate (mL/min)=



2= 2513 πa

2C= 82 2πH/∝

*= 1047

3642 0.055837


Permeameter Test

Test Results

Mountview Dike


1

2441-01010-00

4/23/2020

TP20-03 0.25m bgs

4

10.15492

124

[2πH2 + πa

2C + 2πH/∝

*] in cm

2 = K(fs) = CQ/[2πH

2 + πa

2C + 2πH/∝

*] cm/min =



Comments:

Mt. McLean Street

19°C

25



DCP TEST DATA

Project: Mountview Dike Date: 23-Apr-20

Location: TP20-01 0.5m bgs Soil Type(s): Type in the soil type

No. of Accumulative Type of

Blows Penetration Hammer

(mm)

1 0

25 110

0

5

10

15

20

25

30

35

40

0.1 1.0 10.0 100.0

0

127

254

381

508

635

762

889

1016

0.1 1.0 10.0 100.0

DE

PT

H, in

.CBR

DE

PT

H, m

m

10.1 lbs.17.6 lbs.Both hammers used

Soil TypeSoil TypeCHCLAll other soils


Hammer

0

127

254

381

508

635

762

889

1016

0 14 28 42 56 69 83

0

5

10

15

20

25

30

35

40

0 2000 4000 6000 8000 10000 12000

DE

PT

H, m

m

BEARING CAPACITY, psi

DE

PT

H, in

BEARING CAPACITY, psf

Based on approximate interrelationshipsof CBR and Bearing values (Design ofConcrete Airport Pavement, Portland Cement Association, page 8, 1955)

DCP TEST DATA





(mm)

1 525

20 635

0

5

10

15

20

25

30

35

40

0.1 1.0 10.0 100.0

0

127

254

381

508

635

762

889

1016

0.1 1.0 10.0 100.0

DE

PT

H, in

.CBR

DE

PT

H, m

m




Hammer

0

127

254

381

508

635

762

889

1016

0 14 28 42 56 69 83

0

5

10

15

20

25

30

35

40

0 2000 4000 6000 8000 10000 12000

DE

PT

H, m

m


DE

PT

H, in



DCP TEST DATA





(mm)

1 555

17 700

0

5

10

15

20

25

30

35

40

0.1 1.0 10.0 100.0

0

127

254

381

508

635

762

889

1016

0.1 1.0 10.0 100.0

DE

PT

H, in

.CBR

DE

PT

H, m

m




Hammer

0

127

254

381

508

635

762

889

1016

0 14 28 42 56 69 83

0

5

10

15

20

25

30

35

40

0 2000 4000 6000 8000 10000 12000

DE

PT

H, m

m


DE

PT

H, in



Page | 17

APPENDIX C – LABORATORY TEST RESULTS

Project No: 20.0016.AR Lab ID: S20135

Project: McElhanney General

Client: McElhanney Consulting Services Ltd. Client Project: 2441-01010-00

Attn: Ryan Gibbard Date Received:

CC: -

Sample Date:

Sample Time: -

Sample Description: GRAVEL, some sand, trace silt/clay Sample ID: TP20-02 SA1 @ 0.6m

Sample Source: Geotechnical investigation Sampled By: Client

Specification: NA

100.0 #N/A

75.0 100.0

37.5 62.6

19.0 36.9

12.5 28.7

9.5 25.2

4.75 19.7

2.00 16.1

1.18 14.4

0.600 12.0

0.425 9.8

0.300 7.2

0.150 3.2

0.075 2.0

Summary

Cobble : >75mm %

Gravel : < 75mm and > 4.75mm 80.3 %

Sand : < 4.75mm and > 0.075mm 17.7 %

Silt/Clay : < 0.075mm 2.0 %

Moisture Content: 4.1 %

Comments: -

Reviewed By:

Bryan Morrison, BSc.

PARTICLE SIZE ANALYSIS

April 23, 2020

-

Report Date:

Sieve Analysis

Sieve Size (mm) % PassingSpecification

limits

Tested in accordance with ASTM C136 Sieve Analysis of Fine and Coarse Aggregates /C117 Materials Finer than 75-μm (No. 200) Sieve in Mineral

Aggregates by Washing

April 29, 2020

0

10

20

30

40

50

60

70

80

90

100

0.010.1110100

%

p

a

s

s

i

n

g

Particle Size (mm)

% PASSING VS PARTICLE SIZE

------ Specification limits





CC: -

Sample Description: SAND and SILT/CLAY Sample Date:

Sample ID: TP20-03 SA1 @ 0.25m Sample Time: -


Specification: NA

100.0 #N/A

75.0 #N/A

37.5 #N/A

19.0 #N/A

12.5 #N/A

9.5 #N/A

4.75 100.0

2.00 99.9

1.18 99.5

0.600 98.8

0.425 98.3

0.300 97.7

0.150 86.3

0.075 58.3

Summary

Cobble : >75mm %

Gravel : < 75mm and > 4.75mm %

Sand : < 4.75mm and > 0.075mm 41.7 %

Silt/Clay : < 0.075mm 58.3 %


Comments: -

Reviewed By:



April 23, 2020

-

Report Date:

Sieve Analysis


limits



April 29, 2020

0

10

20

30

40

50

60

70

80

90

100

0.010.1110100

%

p

a

s

s

i

n

g

Particle Size (mm)







CC: -

Sample Description: Sandy GRAVEL, trace silt/clay Sample Date:



Specification: NA

100.0 #N/A

75.0 100.0

37.5 83.4

19.0 54.5

12.5 42.2

9.5 37.7

4.75 30.3

2.00 26.2

1.18 24.5

0.600 15.7

0.425 9.4

0.300 5.8

0.150 3.6

0.075 2.9

Summary

Cobble : >75mm %

Gravel : < 75mm and > 4.75mm 69.7 %

Sand : < 4.75mm and > 0.075mm 27.4 %

Silt/Clay : < 0.075mm 2.9 %


Comments: -

Reviewed By:



April 23, 2020

-

Report Date:

Sieve Analysis


limits



April 29, 2020

0

10

20

30

40

50

60

70

80

90

100

0.010.1110100

%

p

a

s

s

i

n

g

Particle Size (mm)







CC: -

Sample Description: Sandy GRAVEL, trace silt/clay Sample Date:



Specification: NA

100.0 #N/A

75.0 100.0

37.5 78.8

19.0 59.7

12.5 51.3

9.5 47.5

4.75 39.5

2.00 32.9

1.18 30.3

0.600 27.3

0.425 25.0

0.300 21.0

0.150 11.2

0.075 7.6

Summary

Cobble : >75mm 0.0 %

Gravel : < 75mm and > 4.75mm 60.5 %

Sand : < 4.75mm and > 0.075mm 31.9 %

Silt/Clay : < 0.075mm 7.6 %


Comments: Sampled partially dried prior to processing - moisture content does not represent as received.

Reviewed By:


Report Date:

Sieve Analysis


limits



April 29, 2020


April 23, 2020

-

0

10

20

30

40

50

60

70

80

90

100

0.010.1110100

%

p

a

s

s

i

n

g

Particle Size (mm)



Page | 18

APPENDIX D – SLIDE ANALYSIS PRINTOUTS

1.8941.8941.894

W

1.8941.8941.894

Material Name Color Unit Weight(kN/m3) Strength Type Cohesion

(kPa)Phi(deg) Water Surface Hu Type Hu Ru

Sand and Silt 18 Mohr‐Coulomb 0 29 Water Surface Custom 1

Hard Till 20 Infinite strength None 0

Clayey Silt 16 Mohr‐Coulomb 10 0 Water Surface Custom 1

Sandy Gravel 20 Mohr‐Coulomb 0 40 Water Surface Custom 1

Topsoil 15 Mohr‐Coulomb 5 15 Water Surface Custom 1

Dike Fill 20.5 Mohr‐Coulomb 0 36 Water Surface Custom 1

FS: 1.89401Method: gle/morgenstern-priceFS: 1.894010Center: 11.803, 10.394Radius: 10.092Left Slip Surface Endpoint: 11.754, 0.302Right Slip Surface Endpoint: 18.672, 3.000Left Slope Intercept: 11.754 2.500Right Slope Intercept: 18.672 3.000

Safety Factor0.0000.2500.5000.7501.0001.2501.5001.7502.0002.2502.5002.7503.0003.2503.5003.7504.0004.2504.5004.7505.0005.2505.5005.7506.000+

105

0-5

-10

-15

-5 0 5 10 15 20 25 30

Analysis Description Full flood htCompany McElhanneyScale 1:160Drawn By RGFile Name MV-typ-dike-sect-3m.slimDate 2020-05-15, 11:12:55 AM

Project

SLIDE - An Interactive Slope Stability Program

SLIDEINTERPRET 6.039

1.5441.5441.544

W

1.5441.5441.544

Material Name Color Unit Weight(kN/m3) Strength Type Cohesion

(kPa)Phi(deg) Water Surface Hu Type Hu Ru

Sand and Silt 18 Mohr‐Coulomb 0 29 Water Surface Custom 1

Hard Till 20 Infinite strength None 0

Clayey Silt 16 Mohr‐Coulomb 10 0 Water Surface Custom 1

Sandy Gravel 20 Mohr‐Coulomb 0 40 Water Surface Custom 1

Topsoil 15 Mohr‐Coulomb 5 15 Water Surface Custom 1

Dike Fill 20.5 Mohr‐Coulomb 0 36 Water Surface Custom 1

Method: gle/morgenstern-priceFactor of Safety: 1.544Center: 28.222, 8.445Radius: 9.446Left Slip Surface Endpoint: 20.504, 3.000Right Slip Surface Endpoint: 32.453, 0.000

Safety Factor0.0000.2500.5000.7501.0001.2501.5001.7502.0002.2502.5002.7503.0003.2503.5003.7504.0004.2504.5004.7505.0005.2505.5005.7506.000+

105

0-5

-10

-15

5 10 15 20 25 30 35 40

Analysis Description Full flood ht landsideCompany McElhanneyScale 1:160Drawn By RGFile Name MV-typ-dike-sect-3m.slimDate 2020-05-15, 11:12:55 AM

Project

SLIDE - An Interactive Slope Stability Program

SLIDEINTERPRET 6.039

Page | 19

Contact Ryan Gibbard, P.Eng 778-550-2002 [email protected]