Post on 03-Mar-2021
Prepared for:
Lex3 Engineering Inc.
Red Deer, Alberta 10-Jul-20
Geotechnical Investigation Report
BF09254 Bridge Replacement
Range Road 70 – Approx. 550 m South of Hwy 16
Parkland County, AB
Project No. EA16425
‘Wood’ is a trading name for John Wood Group PLC and its subsidiaries
Geotechnical Investigation Report
BF09254 Bridge Replacement
Parkland County, AB
Project No. EA16425
Prepared for: Lex3 Engineering Inc.
Prepared by: Wood Environment & Infrastructure Solutions
5681 70 Street
Edmonton, AB T6B 3P6
10-Jul-20
Copyright and non-disclosure notice The contents and layout of this report are subject to copyright owned by Wood (© Wood Environment & Infrastructure Solutions).
save to the extent that copyright has been legally assigned by us to another party or is used by Wood under license. To the extent
that we own the copyright in this report, it may not be copied or used without our prior written agreement for any purpose other than
the purpose indicated in this report. The methodology (if any) contained in this report is provided to you in confidence and must not
be disclosed or copied to third parties without the prior written agreement of Wood. Disclosure of that information may constitute
an actionable breach of confidence or may otherwise prejudice our commercial interests. Any third party who obtains access to this
report by any means will, in any event, be subject to the Third-Party Disclaimer set out below.
Third-party disclaimer Any disclosure of this report to a third party is subject to this disclaimer. The report was prepared by Wood at the instruction of, and
for use by, our client named on the front of the report. It does not in any way constitute advice to any third party who is able to access
it by any means. Wood excludes to the fullest extent lawfully permitted all liability whatsoever for any loss or damage howsoever
arising from reliance on the contents of this report. We do not however exclude our liability (if any) for personal injury or death
resulting from our negligence, for fraud or any other matter in relation to which we cannot legally exclude liability.
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page ii
Table of contents
1.0 Introduction ........................................................................................................................................................................... 1
2.0 Geotechnical Investigation ............................................................................................................................................... 1
2.1 Field Program ....................................................................................................................................................... 1
2.2 Visual Pavement Assessment ......................................................................................................................... 2
2.3 Laboratory Testing .............................................................................................................................................. 2
3.0 Subsurface Conditions ....................................................................................................................................................... 2
3.1 Soil Stratigraphy .................................................................................................................................................. 2
3.2 General Stratigraphy .......................................................................................................................................... 2
3.2.1 Pavement Structure ........................................................................................................................... 3
3.2.2 Clay Fill .................................................................................................................................................... 3
3.2.3 Clay ........................................................................................................................................................... 4
3.2.4 Gravel and Clay Till ............................................................................................................................ 4
3.2.5 Sand ......................................................................................................................................................... 4
3.2.6 Gravel ...................................................................................................................................................... 4
3.3 Groundwater ......................................................................................................................................................... 4
4.0 Geotechnical Evaluation and Recommendations ................................................................................................... 5
4.1 General Geotechnical Considerations ......................................................................................................... 5
4.2 Site Grading and Backfill .................................................................................................................................. 5
4.3 Excavations ............................................................................................................................................................ 6
4.4 Sideslopes .............................................................................................................................................................. 6
4.5 Frost Action ........................................................................................................................................................... 7
4.6 Limit States Foundation Design .................................................................................................................... 7
4.7 Driven Steel Pile Foundations ........................................................................................................................ 8
4.7.1 Design for Compressive/Tensile Loading ................................................................................. 8
4.7.2 Lateral Load Resistance of Piles .................................................................................................... 9
4.7.3 Group Effects ......................................................................................................................................10
4.7.4 Negative Skin Friction .....................................................................................................................10
4.8 Retaining Walls ..................................................................................................................................................11
4.9 Site Classification for Seismic Response ..................................................................................................11
4.10 Pavement Design Recommendations .......................................................................................................12
4.11 Drainage ...............................................................................................................................................................12
4.12 Testing and Inspection ....................................................................................................................................12
5.0 Closure ...................................................................................................................................................................................13
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page iii
List of Tables
Table 1: Borehole Location and Depth Summary .................................................................................................................... 2
Table 2: Pavement Structure Thicknesses ................................................................................................................................... 3
Table 3: Atterberg Limits of A Clay Fill Sample......................................................................................................................... 3
Table 4: Atterberg Limits of A Clay Sample ............................................................................................................................... 4
Table 5: Groundwater Observations ............................................................................................................................................. 5
Table 6: Soil Parameters Used in Slope Stability Analyses ................................................................................................... 6
Table 7: Typical Geotechnical Resistance Factors for Deep Foundations ...................................................................... 8
Table 8: Unfactored ULS Parameters for Axial Capacity of Driven Piles ......................................................................... 9
Table 9: Reduction Factors for Laterally Loaded Pile Groups .......................................................................................... 10
Table 10: Soil Parameters for Retaining Walls and Soil Retention Systems ............................................................... 11
Table 11: Spectral Acceleration (5% Damped) – NBCC 2015 ........................................................................................... 11
Table 12: Minimum Pavement Structures ................................................................................................................................ 12
Appendices
Appendix A: Borehole Location Plan
Appendix B: Borehole Logs and Explanation of Terms and Symbols
Appendix C: Slope Stability Analyses Results
Appendix D: Limitations
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 1 of 13
1.0 Introduction
Wood Environment & Infrastructure Solutions, a division of Wood Canada Limited (Wood) was retained by
Lex3 Engineering Inc., to conduct a geotechnical investigation for the proposed BF09254 bridge
replacement, located on Range Road 70, approximately 550 m South of Highway 16, in Parkland County,
Alberta. The bridge replacement is in the Legal Subdivision (LSD) NW-18-53-6-W5. The purpose of the
geotechnical evaluation was to investigate the subsoil and groundwater conditions at the site and to
provide geotechnical design and construction recommendations for bridge foundations for the bridge
replacement. It is understood that driven steel piles are the preferred foundation type for this bridge.
It was understood from Lex3, that the final grade of the roadway will be raised by up to 2.8 m prior to the
bridge replacement.
This report summarizes the results of the field and laboratory testing programs, and provides discussion
and recommendations on the design of the bridge substructure, deep foundation design parameters,
excavation and backfilling procedures, seismic site classification, and other associated geotechnical aspects
of the development.
2.0 Geotechnical Investigation
2.1 Field Program
Prior to field drilling, Wood conducted the necessary underground utility clearances on the site through
Alberta One-Call. A pre-drilling hazard assessment, traffic accommodation strategy and a toolbox safety
meeting were conducted by the field crew before commencing the borehole drilling.
The field drilling program was carried out on 16 June 2020. Two boreholes, BH20-01 and BH20-02, were
drilled on the south and north sides of the existing bridge BF09254, to depths of 16.3 m and 17.8 m below
ground surface (bgs), respectively. Both boreholes were advanced using a truck-mounted drill rig equipped
with solid stem augers owned and operated by SPT Drilling Ltd., of St. Albert, Alberta. The borehole locations
are indicated on Figure 1 in Appendix A.
Supervision of the drilling, soil sampling and logging of the various soil strata was performed by Wood
personnel. Disturbed soil samples were obtained from the auger cuttings and from the Standard Penetration
Test (SPT) split barrel sampler for soil classification and laboratory testing. SPTs were conducted at regular
intervals to assess the in-situ strength of the soil types encountered.
A slotted PVC standpipe was installed in borehole BH20-01 at the completion of drilling to allow for future
monitoring of the groundwater levels. The annulus between the PVC standpipe and the borehole wall was
backfilled with sand and soil cuttings and capped at the ground surface with bentonite chips and cold mix
asphalt. A wellhead protection box was installed in borehole BH20-01 to protect the standpipe. The
groundwater conditions encountered in the boreholes during drilling and those measured on 26 June 2020
are reported on the borehole logs.
All soil samples and auger cuttings were visually examined and classified in the field in accordance with the
Modified Unified Soil Classification System (MUSCS) and the results are provided in the borehole logs
included in Appendix B. Summary sheets outlining the terms, abbreviations and symbols used on the
borehole logs are also included with the borehole logs in Appendix B. A summary of the completed
borehole locations and drilling depths is provided in Table 1.
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 2 of 13
Table 1: Borehole Location and Depth Summary
Borehole
ID
Approximate Coordinates (1) Drilled Depth (m) (2)
Northing (m) Easting (m)
BH20-01 5938915 639949 16.3
BH20-02 5938869 639954 17.8 (1) Coordinates are Universal Transverse Mercator (UTM), Zone 11, NAD 83 datum. Borehole coordinates were measured using a
hand-held GPS and should be considered approximate. (2) Drill depths were measured from top of ground surface at time of the investigation.
2.2 Visual Pavement Assessment
A visual assessment of the current pavement condition in the vicinity of the bridge was conducted on 16
June 2020. The visual observation results were as follows:
Generally, the roadway surface condition was considered to be good;
Slight centerline cracking was observed;
No transverse cracks were observed; and
No fatigue cracking or structural failures were observed.
2.3 Laboratory Testing
All geotechnical soil samples were transported to our Edmonton laboratory for routine laboratory testing.
The tests included soil moisture contents, and two Atterberg limits. The results of the testing can be found
on the borehole logs in Appendix B.
3.0 Subsurface Conditions
3.1 Soil Stratigraphy
Detailed descriptions of the subsurface conditions encountered in each borehole are presented on the
borehole logs provided in Appendix B. The boundaries indicated on the borehole log typically represent
transitions from one soil type/consistency to another, and due to the method of drilling, do not necessarily
represent exact depths between soil layers/consistencies. Due to the method of drilling, depths of the
various soil types/consistencies/densities noted on the borehole log may vary by ±0.3 m from the actual
depth. The subsurface conditions were established only at the borehole locations and might vary beyond
the borehole locations.
3.2 General Stratigraphy
The generalized subsurface stratigraphy (from uppermost to lowermost strata) encountered in the
boreholes comprised:
Asphalt Concrete Pavement (ACP) with a thickness of 100 to 110 mm, and gravel fill extending to depths
ranging from 400 mm to 500 mm bgs;
Clay fill, encountered below the pavement structure in both boreholes, extending to a depth of 2.6 m
in borehole BH20-01 and 6.4 m in borehole BH20-02;
Native clay, encountered below the clay fill in both boreholes, extending up to depths of up to 8.5 m
bgs;
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 3 of 13
Gravel, encountered below the native clay in BH20-02, extending to a depth of 10.1 m bgs;
Clay till, encountered below the native clay and extended to a depth of 10.1 m in borehole BH20-01;
and encountered below the gravel and extended to a depth of 12.1 m bgs in BH20-02;
Sand, encountered below the clay till, and extended to a depth of 15.5 m in borehole BH20-01 and to
16.5 m in borehole BH20-02; and
Gravel, encountered below the sand and extended to the termination depth of both boreholes.
3.2.1 Pavement Structure
Both boreholes were advanced through a layer ACP underlain by granular material. A summary of the
pavement structure encountered is shown in Table 2 below.
Table 2: Pavement Structure Thicknesses
Borehole ID
Approximate
Borehole
Location
ACP Thickness
(mm)
Granular Thickness
(mm)
Total Pavement
Structure (mm)
BH20-01
11 m N of
bridge deck,
SBL
100 300 400
BH20-02
9 m S of
bridge deck,
NBL
110 390 500
3.2.2 Clay Fill
Clay fill was encountered underneath the pavement structure gravel in both boreholes, extending to depths
of 2.6 m bgs in in borehole BH20-01 and 6.4 m bgs in boreholes BH20-02. The clay fill was silty, and
contained trace to some organic, some to no sand, and trace to no gravel. A layer of organics with a
thickness of 25 mm was encountered at 1.5 m depth in borehole BH20-01 and at 2.0 m depth in borehole
BH20-02. Wood debris were also encountered in the clay fill in borehole BH20-02 at depths of 3.1 m and
5.6 m bgs. Generally, the clay fill was dark grey in colour.
Moisture contents in the clay fill generally ranged from 30 percent to 46 percent.
One Atterberg limit test was conducted in this soil unit, with the results shown below.
Table 3: Atterberg Limits of a Clay Fill Sample
Sample
ID
Sample
Depth
(m)
In-Situ
Moisture
Content
(%)
Liquid
Limit,
WL
Plastic
Limit
WP
Plasticity
Index
IP
Soil
Classification
BH20-02 1.5 40.4 80.8 30.0 50.8 CH
CH= High plastic clay
SPT N values in the clay fill typically ranged from 6 to 10, indicating a firm to stiff consistency.
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 4 of 13
3.2.3 Clay
Native clay was encountered below the clay fill, extending to depths of 8.5 m bgs in in borehole BH20-01
and 8.3 m bgs in boreholes BH20-02. The clay was silty with trace sand, and dark grey in colour. Moisture
contents in the clay ranged from 36 percent to 60 percent.
One Atterberg limit test was conducted in the clay, with the results shown below.
Table 4: Atterberg Limits of a Clay Sample
Sample
ID
Sample
Depth
(m)
In-Situ
Moisture
Content
(%)
Liquid
Limit,
WL
Plastic
Limit
WP
Plasticity
Index
IP
Soil
Classification
BH20-01 5.3 50.1 73.7 31.8 41.9 CH
SPT N values in the clay typically ranged from 4 to 9, indicating a firm to stiff consistency.
3.2.4 Gravel and Clay Till
A layer of gravel was encountered below the high plastic native clay in borehole BH20-02, extending from
8.3 m to 10.1 m bgs. The gravel was poorly graded, sandy and contained some clay. SPT N values in the
gravel ranged from 12 to 17, indicating a compact density.
Clay till was encountered below the native clay and below the gravel, extending to depths of 10.1 m bgs in
borehole BH20-01 and 12.1 m bgs in boreholes BH20-02, respectively. The clay till was silty with some sand,
medium plastic, dark grey, and contained trace gravel, trace coal and trace shale inclusions. Moisture
contents in the clay till ranged from 18 percent to 31 percent.
SPT N values in the clay till ranged from 7 to 12, indicating a firm to stiff consistency.
3.2.5 Sand
Sand was encountered below the clay till in both boreholes, extending to a depth of 15.5 m in borehole
BH20-01 and 16.5 m in borehole BH20-02. The sand was medium grained, silty, contained trace gravel, and
was dark brown in colour. Moisture contents in the sand ranged from 16 percent to 25 percent.
SPT N values in the sand ranged from 8 to 21, indicating a loose to compact density.
3.2.6 Gravel
Gravel was encountered below the sand, extending to the termination depths of both boreholes. The gravel
was sandy, poorly graded and saturated. Moisture contents in the sand ranged from 16 percent to 25
percent.
SPT N values in the gravel ranged from 53 to 50 for 125 mm, indicating very dense density.
3.3 Groundwater
A standpipe piezometer was installed in borehole BH20-01 to permit short term monitoring of groundwater
levels. Table 5 summarizes groundwater seepage observed during drilling and the groundwater level
measured in the standpipe ten days later.
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 5 of 13
Table 5: Groundwater Observations
Borehole
ID
Depth of
Standpipe
(m)
Depth of Slough at
Drilling Completion
(m)
Depth of Water at
Drilling Completion
(m)
Measured
Groundwater Level on
June 26, 2020 (m)
BH20-01 9.4 8.5 3.9 2.7
BH20-02 - 9.3 3.4 -
These water level measurements are considered preliminary and may not represent stabilized conditions.
The groundwater level is likely related to the water level in the creek under the bridge. Seasonal fluctuations
in groundwater levels should be expected in response to snow melt, heavy rainfall, flooding or other weather
events. Future water level monitoring can be conducted to confirm the magnitude of groundwater
fluctuations at the site.
4.0 Geotechnical Evaluation and Recommendations
4.1 General Geotechnical Considerations
The investigation showed that the site has satisfactory soil conditions for the proposed replacement bridge
foundations. Steel piles driven into the very dense gravel are considered a suitable foundation option for
the bridge foundations. Further information on driven steel piles can be found in Section 4.7.
4.2 Site Grading and Backfill
It is understood that the grade of the roadway will be raised by up to 2.8 m to accommodate the new
bridge. Prior to fill placement, the existing surface ACP should be stripped and removed from site. The
underlying subsurface granular fill materials (existing gravel fill) may be suitable for reuse as Granular Base
Course (GBC) provided they meet the Alberta Transportation requirements for Designation 2 Class 20
granular material, or equivalent.
Following the removal of the pavement structure, the uppermost 150 mm of the exposed surface should
be scarified and recompacted to no less than 98% of the Standard Proctor Maximum Dry Density (SPMDD)
at or near the Optimum Moisture Content (OMC), prior to placement of engineered fill. In general, the
engineered fill should consist of low to medium plastic clay, be placed in uniform 300 mm thick loose lifts
and compacted to 98 percent SPMDD at a moisture content of optimum to 2 percent above optimum
moisture content. If hand-portable compaction equipment is required in confined compaction zones then
thinner lifts should be used such that lift thickness is compatible with the compaction effort available with
the portable equipment (i.e. jumping jack equipment should be 150 mm loose lifts in thickness)
The final prepared subgrade should be proof roll tested, with an axle load of 80 kN, to check for soft, loose
or non-uniform areas. Any such areas detected should reworked and recompacted. To promote positive
drainage, the surface of the subgrade should be prepared with a cross slope of 2% or greater.
In addition to the general site grading required to prepare the road surface, the bridge abutments will
require placement of backfill behind the abutment retaining walls. It is recommended that granular material
consisting of Alberta Transportation Designation 2 Class 25 Granular fill be used for backfill behind the
backwalls. Granular material should be compacted to a minimum of 95 percent SPMDD at a moisture
content within 2 percent of the optimum moisture content. The upper 300 mm beneath the approach slab
should be compacted to a minimum of 100 percent SPMDD at a moisture content within 2 percent of the
optimum moisture content. Only hand operated compaction equipment should be used to compact fill
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 6 of 13
within 0.9 m of wing walls, or other walls with unbalanced earth pressure, to avoid damage due to lateral
stresses caused by compaction.
It should be noted that organic soils were encountered in the fill materials below the existing pavement
structure. If the existing clay fill is re-used for backfill, it must contain no more than 5 percent organic
material. Clay that contains more than 5 percent organic content should be removed and disposed of off-
site or be used for landscaping.
Fill should not be frozen at the time of placement, nor should the fill be placed on a frozen subgrade.
4.3 Excavations
Permanent slopes less than 4 m in height, such as backslopes or headslopes for abutments, may be
designed at slopes of 2H:1V within the near surface clay soils. Where the recommended slope angle cannot
be accommodated, the soil should be removed for a distance of approximately 3 m behind the slope face
and be replaced with compacted engineered fill. Groundwater control and drainage should be provided as
necessary to prevent buildup of hydrostatic groundwater pressure behind the replacement fill. Slope angles
for slopes more than 4 m in height should be reviewed on a case-by-case basis. Traffic safety and roadway
maintenance considerations may require slopes flatter than 2H:1V. Temporary excavations may be designed
at 1H:1V in the clay soils encountered at the site.
4.4 Sideslopes
Slope stability analyses were carried out to assess the sideslope slope stability for 3H:1V, 2.5H:1V, and 2H:1V
slopes using the limit equilibrium slope stability analysis software program Slope/W. Based on the existing
ground condition and the maximum design thickness for the new fill, the soil profile used in the analyses
consisted of 2.8 m of new fill material over 3.5 m of existing clay fill, overlying foundation clay soil.
The soil parameters used in the analyses as presented in Table 6 below, were determined based on the
results of the geotechnical investigation and our past experiences with similar soils.
Table 6: Soil Parameters Used in Slope Stability Analyses
Soil Type
Bulk Unit
Weight
(kN/m3)
Effective
Cohesion C’
(kPa)
Effective Friction
Angle φ’ (º)
New Low to Medium Plastic Clay Fill 19 3 28
Existing High Plastic Embankment Clay
Fill and Foundation Soil 18 2 22
For the sideslope stability analysis, the groundwater table was conservatively estimated as being at the same
elevation as the surrounding ground surface, to provide an allowance for porewater pressure increase
during construction of the new fill.
As shown on Figure 2 through 4 in Appendix C, the calculated factors of safety for the sideslope are 1.47,
1.32, and 1.15 for slopes of 3H:1V, 2.5H:1V, and 2H:1V, respectively.
Based on a minimum long-term sideslope factor of safety 1.3, the sideslope of the embankment can be
constructed with a slope of 2.5H:1V. If the locally accepted minimum long-term sideslope factor of safety is
1.5, the sideslopes should be constructed at a slope of 3H:1V.
The existing 3.5 m high fill was successfully constructed over the native high plastic clay subgrade many
years previous and porewater pressures in the subgrade have returned to equilibrium levels. Thus, it is not
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 7 of 13
expected that instability will develop in the embankment subgrade or sideslopes in response to the addition
of a 2.8 m thickness of new fill. As a precaution, it is recommended that vibrating wire piezometers be
installed in the new fill areas for each embankment to monitor the response of the groundwater level to the
addition of the new fill during the construction period.
The sideslopes should be constructed in accordance with applicable health and safety standards, specifically
the Alberta Occupational Health and Safety Code.
4.5 Frost Action
The near surface clay fill on the site is expected to be moderately frost susceptible. The estimated average
depth of frost penetration for the near surface soils is 1.7 m for a mean annual Air Freezing Index (AFI) of
1,450 degree-days Celsius, and 2.2 m for a 50 year return period AFI of 2,400 degree-days.
The 50-year return period frost penetration depth is generally used for design purposes.
The estimated frost penetration depth is for a uniform soil type with no insulative cover.
4.6 Limit States Foundation Design
The design parameters provided in the following sections are under the framework of Limit State Design
(LSD) methodology. Limit states are defined as conditions under which a structure or its component
members no longer perform their intended function, and are generally classified into the main groups of
Ultimate Limit State or Serviceability Limit State. Each of these limit states are discussed in more detail
below.
Ultimate Limit State (ULS)
Ultimate Limit States are primarily concerned with collapse mechanisms for the structure and, hence, safety.
Foundation designs using a limit states design approach should satisfy the following design equation:
niinSR
Where:
Rn - Factored geotechnical resistance.
- Geotechnical resistance factor.
Rn - Nominal (ultimate) geotechnical resistance determined using unfactored geotechnical
parameters.
iSni - Summation of the factored overall load effects for a given load combination condition.
i - Load factor corresponding to a particular load.
Sni - Specified load component of the overall load effects (e.g. dead load due to weight of
structure or live load due to wind).
i - Various types of loads such as dead load, live load, wind load, etc.
Geotechnical resistance factors as provided by the Canadian Highway Bridge Design Code for deep
foundations are provided in Table 7. The critical design events and their corresponding load combination
and load factors should be assessed and determined by the structural engineer.
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 8 of 13
Table 7: Typical Geotechnical Resistance Factors for Deep Foundations
Limit State Test Method/Model Geotechnical
Resistance Factors
Compression
Static analysis 0.4
Static test 0.6
Dynamic analysis 0.4
Dynamic test 0.5
Tension Static analysis 0.3
Static test 0.5
Lateral Static analysis 0.5
Static test 0.5
Settlement or lateral deflection Static analysis 0.8
Static test 0.9
Note: Canadian Highway Bridge Design Code, S6-14. April 2016. Table 6.2, p 232
Serviceability Limit State (SLS)
Serviceability Limit States are primarily concerned with mechanisms that restrict or constrain the intended
use or function of the structure. For foundation design, serviceability limit states are usually associated with:
► Excessive foundation movements (e.g. settlement, differential settlement, heave, etc.)
► Unacceptable foundation vibrations.
In general, the format criteria for serviceability limit states can be expressed as follows:
Serviceability Limit ≥ Effect of Service Loads
Serviceability Limit States are evaluated using unfactored geotechnical settlement properties (i.e.
compressibility, Young’s Modulus, etc.) to determine a SLS bearing pressure which, when applied to the
foundation soil, will not exceed a specified serviceability criteria. However, the load settlement behaviour of
foundations is complex, and, notwithstanding the non-linear nature of the soil, depends on the foundation
type and foundation configuration. Generally, the recommended pile design parameters provided for the
bridge foundation in this report are based on a vertical pile settlement of less than 10 mm under the design
load.
4.7 Driven Steel Pile Foundations
It is understood that the preferred foundation system for the support of structural loads is driven steel piles.
As previously discussed in Section 4.1, driven steel piles founded in the very dense gravel are considered a
feasible option at the site given the site subsurface conditions.
4.7.1 Design for Compressive/Tensile Loading
The unfactored shaft and toe resistance parameters presented in Table 8 are recommended for the design
of driven steel piles at the site. Geotechnical resistance factors of 0.4 and 0.3 should be applied for
compressive and uplift loads respectively, for ULS design.
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 9 of 13
Table 8: Unfactored ULS Parameters for Axial Capacity of Driven Piles
Depth Below Ground Surface (m) Shaft Resistance
(kPa) Toe Resistance (kPa) 1
Frost and Existing Fill Zone (0 to 6.5) 0 0
Firm Clay (6.5 to 8.5) 25 0
Stiff Clay Till, Gravel, and Sand (8.5 to 12) 40 0
Loose to Compact Sand (12 to 16) 70 1500
Gravel (below 16) 120 2500 1 Unfactored ULS toe resistance for pile diameters less than 0.5 m.
The shaft resistance should not be considered in the existing or new fill zone. The frost zone is considered
to be the soil 2.2 m in thickness extending below where the vertical abutment wall intersects the
embankment slope.
Where practical driving refusal occurs, the piles may be designed on the basis of the allowable fibre stress
of the steel. The factored ULS geotechnical resistance of the pile should be determined by multiplying the
cross-sectional area of steel at the pile tip by 0.4fy, where fy is the yield strength of the steel. The design
value for the steel yield strength for determining allowable load should be limited to 250 MPa.
Piles should be designed to resist uplift due to adfreeze based on an adfreeze uplift value of 100 kPa (for
steel piles) applied over a 2.2 m thick frost zone. Resistance to adfreeze uplift is provided by shaft friction
below the frost zone as well as by dead load carried by the pile.
As a preliminary guide, steel piles should be driven using maximum hammer energies per blow of 450 to
600 J per square centimetre of pile cross section. Piles should not be driven beyond practical refusal, which
may be taken, on a preliminary basis, as 10 to 12 blows per each 25 mm interval for the last 150 mm of
driving. The value for practical driving refusal should be determined using WEAP analysis when the pile
sections/lengths and type of driving equipment are known.
When uniform high driving resistance has been observed over a substantial length of driving, without
practical refusal being obtained, adjustment to the pile length could be considered in consultation with the
designer. Driving should be stopped immediately if abrupt penetration refusal is encountered, or if pile
damage is occurring, and the pile capacity should be assessed in consultation with this office.
Where the design is based on driving set criteria, the elevations of the tops of previously installed piles
within 5 pile diameters should be monitored during subsequent adjacent pile installation. Piles that have
heaved should be re-driven.
In the case of H-piles, the skin friction values should be applied to the net perimeter of the piles. The end
bearing values should be applied to the gross (plugged) end area of the pile.
4.7.2 Lateral Load Resistance of Piles
The lateral load resistance of piles depends essentially both on the stiffness of the pile and the strength of
the surrounding soil. Analytical methods using soil-pile load interaction curves (p-y curves) offer a widely
accepted basis for predicting pile-soil interaction with practical accuracy and simplicity. However, to use the
p-y curve method to assess pile lateral resistance capacity, the pile configurations, and the operational
requirements of the supported facilities need to be known. Therefore, this may be performed during later
stages of the project when more information on the pile geometry and loading conditions becomes
available.
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 10 of 13
4.7.3 Group Effects
Axial Loading
In accordance with the Canadian Highway Bridge Design Code (CAN/CSA-S6-06), where the centre-to-
centre spacing of piles at the underside of the pile cap is less than 3 pile diameters or less than 750 mm,
the effects of interaction between piles shall be considered. The factored vertical resistance of a pile group
shall be determined as follows:
► The factored geotechnical resistance of a group of piles bearing on rock, dense sand, or hard till
with no weak strata beneath the bearing layer shall be taken as the sum of the factored axial
geotechnical resistances of the individual piles in the group; or
► The factored geotechnical resistance of a group of piles that derive their resistance primarily from
shaft friction shall be taken as the lesser of the following:
► the sum of the factored geotechnical resistances of the individual piles in the group; or
► the factored geotechnical resistance of an equivalent block enclosing the pile group
Lateral Loading
If it is desirable to limit the horizontal deflection of a pile group to that of a single pile, then the load on the
adjacent piles must be multiplied by a reduction factor. The recommended reduction factors for pile groups
are provided in Table 9, below.
Table 9: Reduction Factors for Laterally Loaded Pile Groups
4.7.4 Negative Skin Friction
The final grade of the roadway will be raised and newly added fill materials are expected in the abutment
areas. Driven steel piles installed through the fill may therefore be subjected to downdrag due to long term
settlement of the fill materials.
The downdrag load increases the structural load on the pile and thus has to be accounted for when
evaluating the structural limit state of the pile. The negative skin friction may be calculated as a triangular
distribution through the newly added fill at the pile locations, equal to 6.6 x H kPa, where H varies from zero
to the new fill depth. The downdrag loads are unfactored and an appropriate structural load factor should
be applied.
It is important to note that downdrag load and transient live load do not combine, and that two separate
structural loading cases should be considered: permanent load plus downdrag load, but no transient load;
and permanent load plus transient live load, but no downdrag load. The structural pile capacity is not
Spacing Between Pile Centres (Pile Diameters) Reduction Factor
8 1.00
7 0.90
6 0.75
5 0.65
4 0.50
3 0.40
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 11 of 13
expected to be a governing factor for driven steel piles for this project. Downdrag does not reduce the ULS
geotechnical pile capacity.
4.8 Retaining Walls
Retaining walls up to approximately 4 m in height may be required at the bridge abutment areas to limit
the lateral extent of sideslopes and headslopes. The following soil parameters may be used in design of
gravity retaining wall systems. It should be noted that the following assumptions are associated with the
parameters provided in Table 10.
► The retained fill has a level backslope;
► No surcharge loads and earthquake load are considered; and
► Sufficient sub-drainage will be provided behind the wall, and hence water pressure will not build
up behind the wall.
Table 10: Soil Parameters for Retaining Walls and Soil Retention Systems
Soil Type
Active Earth
Pressure
Coefficient
Ka
At Rest Earth
Pressure
Coefficient K0
Passive Earth
Pressure
Coefficient Kp
Friction Angle
(º)
Soil Unit
Weight
(kN/m3)
Engineered Fill
Cohesive Soil 0.38 0.55 2.66 27 18
Engineered Fill
Granular Soil 0.27 0.43 3.69 35 21
For protection against the effects of frost, positive drainage should be provided behind earth retaining
structures, and the bases of the structures should be provided with 2.2 m of soil cover, or an equivalent
amount of insulation.
4.9 Site Classification for Seismic Response
In the National Building Code of Canada (NBCC, 2015), the seismic hazard is described by spectral
acceleration values at various periods and the peak ground acceleration (PGA). The spectral acceleration is
a measure of ground motion that takes into account the sustained shaking energy produced by an
earthquake at a particular period. The spectral acceleration values for the site under a 1 in 2,475-year
earthquake were obtained by using the Online Seismic Hazard Interpolator provided by Natural Resources
Canada. Table 11 summarizes the spectral acceleration for firm ground at the subject site.
Table 11: Spectral Acceleration (5% Damped) – NBCC 2015
Period (s) PGA Sa(0.2) Sa(0.5) Sa(2.0) Sa(5.0) Sa(10.0)
Acceleration 0.076 g 0.125 g 0.079 0.023 0.006 0.003
For foundation effects, the NBCC incorporates site effects by categorizing the subsoil into six types based
on the average shear wave velocity (Vs) or standard penetration resistance (N60) for the upper 30 m.
A site class D may be used for the design of the proposed structures. Shear wave velocity data was not
obtained from this site, and borings were not advanced to 30 m depth. This seismic classification is based
Geotechnical Investigation Report
BF09254 Bridge Replacement
Project No. EA16425 | 7/10/2020 Page 12 of 13
on the SPT ‘N’ values within the depths drilled at the site, as well as on the assumption that the soil strength
below the depths drilled is at least as high as that encountered at the borehole termination depths.
4.10 Pavement Design Recommendations
It is understood that roadway reconstruction is required to accommodate the proposed change in bridge
elevation. The roadway section requiring reconstruction is approximately 200 to 300 m in length.
A flexible pavement design was performed in accordance with the guidelines described in the Alberta
Transportation (AT) Pavement Design Manual 1997 which adopts the pavement design procedures of
American Association of State Highway and Transportation Officials (AASHTO), 1993. Based on a reliability
of 85%, and a 20 year estimated design traffic volume of 3 x 105 Equivalent Single Axle Loads (ESALs).
Based on the performance of the existing roadway, a pavement structure similar to the pavement structure
observed on site is recommended, as provided in Table 12.
Table 12: Minimum Pavement Structures
Layer Thickness (mm)
Asphalt Concrete Pavement (ACP) 100
Granular Base Course (GBC) 350
Design SN 89
SN Required 85
The GBC materials should be uniformly compacted to a minimum of 100 percent of SPMDD within +/-3.0
percent of OMC, and consist of consisting of AT Designation 2, Class 20 aggregate, or equivalent.
The ACP should be constructed in 2 lifts, be compacted to a minimum of 97 % of the Marshal Mix Design
and should comply with the latest Parkland County Hot-Mix Asphalt Concrete Paving procedures.
4.11 Drainage
It is recommended that the geometric design of the roadway includes provision for an adequate ditch
drainage system capable of directing surface and sub-surface water away from the top of subgrade and
pavement structure. The design of the drainage system should be in accordance with the Highway
Geometric Design Guide published by Alberta Transportation, or equivalent. Roadside ditches should be
sized adequately to accommodate the anticipated flows during storm events and should be graded towards
low-lying discharge points. To protect the subgrade from wetting and weakening, it is also recommended
to maintain the bottom of ditches a minimum of 1.0 m below the top of subgrade.
4.12 Testing and Inspection
All engineering design recommendations presented in this report are based on the two boreholes advanced
on the site, and on the assumption that an adequate level of inspection will be provided during construction
and that all construction will be carried out by a suitably qualified contractor experienced in foundation and
earthworks construction. An adequate level of inspection is considered to be:
► For deep foundations: design review and full-time inspection during construction
► For earthworks: full time monitoring and compaction testing
Appendix A
Borehole Location Plan
NTS
PROJECT:
A1
Pri
nte
d:
07
/08
/20
1
1:4
4 A
MA
:\M
at\
PR
OJE
CT
S\A
ll P
roje
cts
\16
40
1-1
64
50
\EA
16
42
5 -
Le
x3
BF
09
25
4 -
RR
70
- G
eo
In
v\R
ep
ort
\[F
igu
re 1
- B
H L
oca
tio
ns.x
lsx]L
an
dsca
pe
EA16425
CLIENT:
LEX3 ENGINEERING INC. July 2020
BF09254 BRIDGE REPLACEMENT
TITLE:BOREHOLE LOCATION PLAN
DATE: JOB No.: FIGURE No.: REV.
BH20-01
BH20-02
Appendix B
Borehole Logs and Explanation of Terms and Symbols
ASPHALT100 mm thickGRAVEL FILLsandy, some silt, well graded, brown, damp, 300 mm thickCLAY FILLsilty, trace organics, high plastic, stiff, dark grey, moist
... organic seam, 25 mm thick at 1.5 m
... some sand, trace gravel below 1.6 m
... some organic, black below 2.3 m
CLAYsilty, trace sand, high plastic, stiff, dark grey, moist
... no sand, firm, wet below 3.2 m
... sand layer, 25 mm thick, some seepage at 8.3 mCLAY TILLsilty, some sand, trace gravel, trace coal, medium plastic,firm, dark grey, moist
... trace shale inclusions below 9.3 m
9
12
6
6
4
9
D1
G2
D3
G4
D5
G6
D7
G8
D9
G10
D11
G12
ASPH
FILL
CH
CH
CI
6/26/2020
6/16/2020
COMPLETION DEPTH: 16.3 mCOMPLETION DATE: 6/16/20
BLOW COUNT (N)
20 40 60 80
1
2
3
4
5
6
7
8
9
20 40 60 80
Page 1 of 2
1
2
3
4
5
6
7
8
9
M.C.PLASTIC
SOILDESCRIPTION D
epth
(m)
SOIL
SYM
BOL
Dep
th (m
)
10
LIQUID
OTHER TESTSCOMMENTS
0
ENTERED BY: NRLOGGED BY: NRREVIEWED BY: YY
Grab Sample
Grout
SPT Test (N)
Slough
CoreSAMPLE TYPE
BOREHOLE NO.: BH20-01
PROJECT NO.: EA16425
ELEVATION:
BF09254 Bridge Replacement
SITE: RR70, 500 m S of Hwy 16
SBL, 11 m N of Bridge, 11U N:5938915 E:639949
BACKFILL TYPE
Split-Pen
Drill Cuttings
Shelby Tube
Bentonite Sand
No Recovery
Pea Gravel
Lex3 Engineering Ltd.
SPT Drilling Ltd.
Solid Stem Auger
Environment & Infrastructure Solutions5681 - 70 Street NW
Edmonton, Alberta, T6B 3P6A:\
MA
T\P
RO
JEC
TS
\AL
L P
RO
JEC
TS
\16
40
1-1
64
50
\EA
16
42
5 -
LE
X3
BF
09
25
4 -
RR
70
- G
EO
IN
V\B
H L
OG
S\E
A1
64
25
BH
LO
GS
.GP
J 2
0/0
7/1
0 1
1:5
0 A
M
(BO
RE
HO
LE
RE
PO
RT
; W
OO
D G
EO
.GL
B)
SPT
(N)
SAM
PLE
NO
SAM
PLE
TYPE
USC
S
SLO
TTED
PIEZ
OM
ETER
SANDsilty, medium grained, compact, dark brown, wet, seepage
... gravelly below 15 m
GRAVELsandy, poorly graded, very dense, saturated
BOREHOLE TERMINATED AT 16.3 m DEPTHBorehole remained open to 8.5 m with water accumulationat 3.9 m below existing grade 10 minutes after drillingcompletion.Borehole was installed with a 25 mm standpipe, slotted from6.4 to 9.4 m.Borehole was backfilled with drill cuttings, bentonite and aroad box installed at the surface.Water level at 2.7 m on 26 June 2020.
7
14
21
50/125
D13
G14
D15
G16
D17
G18
G19
G20
D21
SM
GP
COMPLETION DEPTH: 16.3 mCOMPLETION DATE: 6/16/20
BLOW COUNT (N)
20 40 60 80
11
12
13
14
15
16
17
18
19
20 40 60 80
Page 2 of 2
11
12
13
14
15
16
17
18
19
M.C.PLASTIC
SOILDESCRIPTION D
epth
(m)
SOIL
SYM
BOL
Dep
th (m
)
20
LIQUID
OTHER TESTSCOMMENTS
10
ENTERED BY: NRLOGGED BY: NRREVIEWED BY: YY
Grab Sample
Grout
SPT Test (N)
Slough
CoreSAMPLE TYPE
BOREHOLE NO.: BH20-01
PROJECT NO.: EA16425
ELEVATION:
BF09254 Bridge Replacement
SITE: RR70, 500 m S of Hwy 16
SBL, 11 m N of Bridge, 11U N:5938915 E:639949
BACKFILL TYPE
Split-Pen
Drill Cuttings
Shelby Tube
Bentonite Sand
No Recovery
Pea Gravel
Lex3 Engineering Ltd.
SPT Drilling Ltd.
Solid Stem Auger
Environment & Infrastructure Solutions5681 - 70 Street NW
Edmonton, Alberta, T6B 3P6A:\
MA
T\P
RO
JEC
TS
\AL
L P
RO
JEC
TS
\16
40
1-1
64
50
\EA
16
42
5 -
LE
X3
BF
09
25
4 -
RR
70
- G
EO
IN
V\B
H L
OG
S\E
A1
64
25
BH
LO
GS
.GP
J 2
0/0
7/1
0 1
1:5
0 A
M
(BO
RE
HO
LE
RE
PO
RT
; W
OO
D G
EO
.GL
B)
SPT
(N)
SAM
PLE
NO
SAM
PLE
TYPE
USC
S
SLO
TTED
PIEZ
OM
ETER
50/125
ASPHALT110 mm thickGRAVEL FILLsandy, some silt, well graded, brown, damp, 390 mm thickCLAY FILLsilty, trace sand, trace gravel, trace organics, high plastic,firm, dark grey, moist
... organic layer, 25 mm thick at 2.0 m
... wood debris, some organic at 3.1 m
... wood debris, gravelly, some organic, seepage below 5.6m
CLAYsilty, trace sand, high plastic, firm, dark grey, moist
GRAVELsandy, some clay, poorly graded, dark grey, wet, seepage
6
7
10
6
5
12
G1
D2
G3
D4
G5
D6
G7
D8
G9
D10
G11
D12
G13
ASPH
FILL
CH
CH
GP
6/16/2020
COMPLETION DEPTH: 17.8 mCOMPLETION DATE: 6/16/20
BLOW COUNT (N)
20 40 60 80
1
2
3
4
5
6
7
8
9
20 40 60 80
Page 1 of 2
1
2
3
4
5
6
7
8
9
M.C.PLASTIC
SOILDESCRIPTION D
epth
(m)
SOIL
SYM
BOL
Dep
th (m
)
10
LIQUID
OTHER TESTSCOMMENTS
0
ENTERED BY: NRLOGGED BY: NRREVIEWED BY: YY
Grab Sample
Grout
SPT Test (N)
Slough
CoreSAMPLE TYPE
BOREHOLE NO.: BH20-02
PROJECT NO.: EA16425
ELEVATION:
BF09254 Bridge Replacement
SITE: RR70, 500 m S of Hwy 16
NBL, 11 m N of Bridge, 11U N:5938869 E:639954
BACKFILL TYPE
Split-Pen
Drill Cuttings
Shelby Tube
Bentonite Sand
No Recovery
Pea Gravel
Lex3 Engineering Ltd.
SPT Drilling Ltd.
Solid Stem Auger
Environment & Infrastructure Solutions5681 - 70 Street NW
Edmonton, Alberta, T6B 3P6A:\
MA
T\P
RO
JEC
TS
\AL
L P
RO
JEC
TS
\16
40
1-1
64
50
\EA
16
42
5 -
LE
X3
BF
09
25
4 -
RR
70
- G
EO
IN
V\B
H L
OG
S\E
A1
64
25
BH
LO
GS
.GP
J 2
0/0
7/1
0 1
1:5
0 A
M
(BO
RE
HO
LE
RE
PO
RT
; W
OO
D G
EO
.GL
B)
SPT
(N)
SAM
PLE
NO
SAM
PLE
TYPE
USC
S
BAC
KFIL
LD
ETAI
LS
CLAY TILLsilty, some sand, trace gravel, trace coal, medium plastic,stiff, dark grey, moist... highly weathered shale layer, 150 m thick, at 10.3 m
SANDsilty, trace gravel, medium grained, loose, dark brown, wet
... no soil recovery on auger below 15.5 m
GRAVELsandy, poorly graded, very dense, saturated
BOREHOLE TERMINATED AT 17.8 m DEPTHBorehole remained open to 9.3 m with water accumulationat 3.4 m below existing grade 10 minutes after drillingcompletion.Borehole was backfilled with drill cuttings, bentonite and acold mix asphalt at the surface.
17
12
8
11
53
D14
G15
D16
G17
D18
G19
D20
D24
CI
SM
GP
COMPLETION DEPTH: 17.8 mCOMPLETION DATE: 6/16/20
BLOW COUNT (N)
20 40 60 80
11
12
13
14
15
16
17
18
19
20 40 60 80
Page 2 of 2
11
12
13
14
15
16
17
18
19
M.C.PLASTIC
SOILDESCRIPTION D
epth
(m)
SOIL
SYM
BOL
Dep
th (m
)
20
LIQUID
OTHER TESTSCOMMENTS
10
ENTERED BY: NRLOGGED BY: NRREVIEWED BY: YY
Grab Sample
Grout
SPT Test (N)
Slough
CoreSAMPLE TYPE
BOREHOLE NO.: BH20-02
PROJECT NO.: EA16425
ELEVATION:
BF09254 Bridge Replacement
SITE: RR70, 500 m S of Hwy 16
NBL, 11 m N of Bridge, 11U N:5938869 E:639954
BACKFILL TYPE
Split-Pen
Drill Cuttings
Shelby Tube
Bentonite Sand
No Recovery
Pea Gravel
Lex3 Engineering Ltd.
SPT Drilling Ltd.
Solid Stem Auger
Environment & Infrastructure Solutions5681 - 70 Street NW
Edmonton, Alberta, T6B 3P6A:\
MA
T\P
RO
JEC
TS
\AL
L P
RO
JEC
TS
\16
40
1-1
64
50
\EA
16
42
5 -
LE
X3
BF
09
25
4 -
RR
70
- G
EO
IN
V\B
H L
OG
S\E
A1
64
25
BH
LO
GS
.GP
J 2
0/0
7/1
0 1
1:5
0 A
M
(BO
RE
HO
LE
RE
PO
RT
; W
OO
D G
EO
.GL
B)
SPT
(N)
SAM
PLE
NO
SAM
PLE
TYPE
USC
S
BAC
KFIL
LD
ETAI
LS
EXPLANATION OF TERMS AND SYMBOLS
The terms and symbols used on the borehole logs to summarize the results of field investigation and subsequent laboratory testing are described in these pages. It should be noted that materials, boundaries and conditions have been established only at the borehole locations at the time of investigation and are not necessarily representative of subsurface conditions elsewhere across the site. TEST DATA
Data obtained during the field investigation and from laboratory testing are shown at the appropriate depth interval. Abbreviations, graphic symbols, and relevant test method designations are as follows:
*C Consolidation test *ST Swelling test DR Relative density TV Torvane shear strength *k Permeability coefficient VS Vane shear strength *MA Mechanical grain size analysis w Natural Moisture Content (ASTM D2216) and hydrometer test wl Liquid limit (ASTM D 423) N Standard Penetration Test
(CSA A119.1-60) wp Plastic Limit (ASTM D 424)
Nd Dynamic cone penetration test Ef Unit strain at failure NP Non plastic soil γ Unit weight of soil or rock pp Pocket penetrometer strength (kg/cm²) γd Dry unit weight of soil or rock *q Triaxial compression test ρ Density of soil or rock qu Unconfined compressive strength ρd Dry Density of soil or rock *SB Shearbox test Cu Undrained shear strength SO4 Concentration of water-soluble sulphate → Seepage ▼ Observed water level
* The results of these tests are usually reported separately
Soils are classified and described according to their engineering properties and behaviour. The soil of each stratum is described using the Unified Soil Classification System1
modified slightly so that an inorganic clay of “medium plasticity” is recognized.
The modifying adjectives used to define the actual or estimated percentage range by weight of minor components are consistent with the Canadian Foundation Engineering Manual2
.
Relative Density and Consistency:
Cohesionless Soils Cohesive Soils Relative Density SPT (N) Value Consistency Undrained Shear Approximate Strength cu (kPa) SPT (N) Value Very Loose 0-4 Very Soft 0-12 0-2 Loose 4-10 Soft 12-25 2-4 Compact 10-30 Firm 25-50 4-8 Dense 30-50 Stiff 50-100 8-15 Very Dense >50 Very Stiff 100-200 15-30 Hard >200 >30
The number of blows by a 63.6kg hammer dropped 760 mm to drive a 50 mm diameter open sampler attached to “A” drill rods for a distance of 300 mm.
Standard Penetration Resistance (“N” value)
1 “Unified Soil Classification System”, Technical Memorandum 36-357 prepared by Waterways Experiment Station, Vicksburg,
Mississippi, Corps of Engineers, U.S. Army. Vol. 1 March 1953. 2 ”Canadian Foundation Engineering Manual”, 4th Edition, Canadian Geotechnical Society, 2006.
FIN
E-G
RA
INE
D S
OIL
S
(MO
RE
TH
AN
HA
LF
BY
WE
IGH
T S
MA
LL
ER
TH
AN
75
µm)
OR
GA
NIC
SIL
TS
& C
LA
YS
BE
LO
W "
A"
LIN
E
CLA
YS
AB
OV
E "
A"
LIN
E
NE
GL
IGIB
LE
OR
GA
NIC
CO
NT
EN
T
SIL
TS
BE
LO
W "
A"
LIN
E
NE
GL
IGIB
LE
OR
GA
NIC
CO
NT
EN
T
SA
ND
S
MO
RE
TH
AN
HA
LF
TH
E
CO
AR
SE
FR
AC
TIO
N
SM
ALL
ER
TH
AN
4.7
5m
m
GR
AV
ELS
MO
RE
TH
AN
HA
LF
TH
E
CO
AR
SE
FR
AC
TIO
N
LA
RG
ER
TH
AN
4.7
5m
m
CO
AR
SE
GR
AIN
ED
SO
ILS
(MO
RE
TH
AN
HA
LF
BY
WE
IGH
T L
AR
GE
R T
HA
N 7
5µm
)MAJOR DIVISION TYPICAL DESCRIPTION
MODIFIED UNIFIED CLASSIFICATION SYSTEM FOR SOILS
GW
GP
GM
GC
SW
SP
SM
SC
ML
MH
CL
CI
CH
OL
OH
PtHIGHLY ORGANIC SOILS
LIMESTONE
SANDSTONE
OILSAND
SHALE
FILL (UNDIFFERENTIATED)SILTSTONE
SOIL COMPONENTS
SPECIAL SYMBOLS
FRACTION
PASSING PERCENT
DEFINING RANGES OF
PERCENTAGE BY WEIGHT OF
MINOR COMPONENTS
DESCRIPTORGRAVEL
COARSE
FINE
SAND
COARSE
MEDIUM
FINE
35-50
20-35
10-20
1-10
76mm 19mm
19mm 4.75mm
4.75mm 2.00mm
2.00mm
OVERSIZED MATERIAL
ROUNDED OR SUBROUNDED:
COBBLES 76mm TO 200mm
BOULDERS > 200mm
NOT ROUNDED:
ROCK FRAGMENTS > 76mm
ROCKS > 0.76 CUBIC METRE IN VOLUME
AND
Y/EY
SOME
TRACE
ALL SIEVE SIZES MENTIONED ON THIS CHART ARE U.S. STANDARD A.S.T.M. E.11
RED
RED
YELLOW
YELLOW
RED
RED
YELLOW
YELLOW
SILTY SANDS, SAND-SILT MIXTURES
GREEN
BLUE
GREEN
BLUE
GREEN
BLUE
ORANGE
ORGANIC CLAYS OF HIGH PLASTICITY
60
W < 50%L
W < 50%L
W < 30%L
30% <W < 50%L
W > 50%L
W < 50%L
W > 50%L
D (D )
D10
CU >6; CC D DX10 60
602
= = = 1 to 3
60D (D )
D10
CU >4; CCD DX10 60
302
= =
75µm
425µm 75µm
425µm
FINES (SILT OR CLAY
BASED ON
PLASTICITY)
1.
2. COARSE GRAIN SOILS WITH 5 TO 12% FINES GIVEN COMBINED GROUP SYMBOLS,
E.G. GW-GC IS A WELL GRADED GRAVEL SAND MIXTURE WITH CLAY BINDER
BETWEEN 5 AND 12% FINES.
CL - ML
CL
CI
CH
OH & MH
ML & OL
0
4
7
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100
'' A ''
LINE
PLA
ST
ICIT
Y IN
DE
X (%
)
LIQUID LIMIT (%)
PLASTICITY CHART FOR
SOILS PASSING 425 µm SIEVE
ATTERBERG LIMITS
BELOW "A" LINE OR
P.I. LESS THAN 4
ATTERBERG LIMITS
ABOVE "A" LINE
P.I. MORE THAN 7
ATTERBERG LIMITS
BELOW "A" LINE OR
P.I. LESS THAN 4
ATTERBERG LIMITS
ABOVE "A" LINE
P.I. MORE THAN 7
= 1 to 3
STRONG COLOUR OR ODOUR, AND OFTEN
FIBEROUS TEXTURE
NOT MEETING ABOVE
REQUIREMENTS
NOT MEETING ABOVE
REQUIREMENTS
CLASSIFICATION IS
BASED UPON
PLASTICITY CHART
(SEE BELOW)
WHENEVER THE NATURE OF THE FINES
CONTENT HAS NOT BEEN DETERMINED, IT
IS DESIGNATED BY THE LETTER "F", E.G. SF
IS A MIXTURE OF SAND WITH SILT OR CLAY
PEAT AND OTHER HIGHLY
ORGANIC SOILS
ORGANIC SILTS AND ORGANIC SILTY
CLAYS OF LOW PLASTICITY
INORGANIC CLAYS OF HIGH
PLASTICITY, FAT CLAYS
INORGANIC CLAYS OF MEDIUM
PLASTICITY, SILTY CLAYS
INORGANIC CLAYS OF LOW
PLASTICITY, GRAVELLY, SANDY
OR SILTY CLAYS, LEAN CLAYS
INORGANIC SILTS, MICACEOUS OR
DIATOMACEOUS, FINE SANDS OR
SILTY SOILS
INORGANIC SILTS AND VERY FINE SANDS,
ROCK FLOUR, SILTY SANDS OF SLIGHT
PLASTICITY
CLAYEY SANDS, SAND-CLAY
MIXTURES
POORLY GRADED SANDS, GRAVELLY
SANDS, LITTLE OR NO FINES
WELL GRADED SANDS, GRAVELLY
SANDS, LITTLE OR NO FINES
CLAYEY GRAVELS, GRAVEL-SAND-
CLAY MIXTURES
SILTY GRAVELS, GRAVEL-SAND-SILT
MIXTURES
POORLY GRADED GRAVELS,
GRAVEL-SAND MIXTURES, LITTLE OR
NO FINES
WELL GRADED GRAVELS, GRAVEL-SAND
MIXTURES, LITTLE OR NO FINES
CONTENT
OF FINES
EXCEEDS
12 %
CONTENT
OF FINES
EXCEEDS
12 %
GROUP
SYMBOL
GRAPH
SYMBOL
COLOUR
CODE
LABORATORY
CLASSIFICATION
CRITERIA
U.S. STANDARD
SIEVE SIZE
RETAINED
GREEN-
BLUE
CLEAN GRAVELS
(LITTLE OR NO
FINES)
DIRTY GRAVELS
(WITH SOME
FINES)
CLEAN SANDS
(LITTLE OR NO
FINES)
DIRTY SANDS
(WITH SOME
FINES)
NOTES:
Appendix C
Slope Stability Analysis Results
1.468
-34 -29 -24 -19 -14 -9 -4 1 6 11 16 21 26 31 36-15
-13
-11
-9
-7
-5
-3
-1
1
3
5
7
9
11
13
Name: High Plastic ClayModel: Mohr-CoulombUnit Weight: 18 kN/m³Cohesion': 2 kPaPhi': 22 °
Name: Low to Medium Plastic Clay FillModel: Mohr-CoulombUnit Weight: 19 kN/m³Cohesion': 3 kPaPhi': 28 °
Figure 2. 3H:1V Slope
1.317
-34 -29 -24 -19 -14 -9 -4 1 6 11 16 21 26 31 36-15
-13
-11
-9
-7
-5
-3
-1
1
3
5
7
9
11
13
Name: High Plastic ClayModel: Mohr-CoulombUnit Weight: 18 kN/m³Cohesion': 2 kPaPhi': 22 °
Name: Low to Medium Plastic Clay FillModel: Mohr-CoulombUnit Weight: 19 kN/m³Cohesion': 3 kPaPhi': 28 °
Figure 3. 2.5H:1V Slope
1.148
-34 -29 -24 -19 -14 -9 -4 1 6 11 16 21 26 31 36-15
-13
-11
-9
-7
-5
-3
-1
1
3
5
7
9
11
13
Name: High Plastic ClayModel: Mohr-CoulombUnit Weight: 18 kN/m³Cohesion': 2 kPaPhi': 22 °
Name: Low to Medium Plastic Clay FillModel: Mohr-CoulombUnit Weight: 19 kN/m³Cohesion': 3 kPaPhi': 28 °
Figure 4. 2H:1V Slope
Appendix D
Limitations
Project No. EA16425 | 7/10/2020 Page 18 of 25
LIMITATIONS TO GEOTECHNICAL REPORTS
1. The work performed in the preparation of this report and the conclusions presented herein are subject
to the following:
a) The contract between Wood and the Client, including any subsequent written amendment or
Change Order dully signed by the parties (hereinafter together referred as the “Contract”);
b) Any and all time, budgetary, access and/or site disturbance, risk management preferences,
constraints or restrictions as described in the contract, in this report, or in any subsequent
communication sent by Wood to the Client in connection to the Contract; and
c) The limitations stated herein.
2. Standard of care: Wood has prepared this report in a manner consistent with the level of skill and are
ordinarily exercised by reputable members of Wood’s profession, practicing in the same or similar
locality at the time of performance, and subject to the time limits and physical constraints applicable
to the scope of work, and terms and conditions for this assignment. No other warranty, guaranty, or
representation, expressed or implied, is made or intended in this report, or in any other
communication (oral or written) related to this project. The same are specifically disclaimed, including
the implied warranties of merchantability and fitness for a particular purpose.
3. Limited locations: The information contained in this report is restricted to the site and structures
evaluated by Wood and to the topics specifically discussed in it, and is not applicable to any other
aspects, areas or locations.
4. Information utilized: The information, conclusions and estimates contained in this report are based
exclusively on: i) information available at the time of preparation, ii) the accuracy and completeness of
data supplied by the Client or by third parties as instructed by the Client, and iii) the assumptions,
conditions and qualifications/limitations set forth in this report.
5. Accuracy of information: No attempt has been made to verify the accuracy of any information
provided by the Client or third parties, except as specifically stated in this report (hereinafter “Supplied
Data”). Wood cannot be held responsible for any loss or damage, of either contractual or extra-
contractual nature, resulting from conclusions that are based upon reliance on the Supplied Data.
6. Report interpretation: This report must be read and interpreted in its entirety, as some sections could
be inaccurately interpreted when taken individually or out-of-context. The contents of this report are
based upon the conditions known and information provided as of the date of preparation. The text of
the final version of this report supersedes any other previous versions produced by Wood.
7. No legal representations: Wood makes no representations whatsoever concerning the legal
significance of its findings, or as to other legal matters touched on in this report, including but not
limited to, ownership of any property, or the application of any law to the facts set forth herein. With
respect to regulatory compliance issues, regulatory statutes are subject to interpretation and change.
Such interpretations and regulatory changes should be reviewed with legal counsel.
Project No. EA16425 | 7/10/2020 Page 19 of 25
8. Decrease in property value: Wood shall not be responsible for any decrease, real or perceived, of the
property or site’s value or failure to complete a transaction, as a consequence of the information
contained in this report.
9. No third party reliance: 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 or reproduction which any third party
makes of the report, in whole or in 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 does not
represent or warrant the accuracy, completeness, merchantability, fitness for purpose or usefulness of
this document, or any information contained in this document, for use or consideration by any 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 this
report or anything set out therein. including without limitation, any indirect, special, incidental,
punitive or consequential loss, liability or damage of any kind.
10. Assumptions: Where design recommendations are given in this report, they apply only if the project
contemplated by the Client is constructed substantially in accordance with the details stated in this
report. It is the sole responsibility of the Client to provide to Wood changes made in the project,
including but not limited to, details in the design, conditions, engineering or construction that could in
any manner whatsoever impact the validity of the recommendations made in the report. Wood shall
be entitled to additional compensation from Client to review and assess the effect of such changes to
the project.
11. Time dependence: If the project contemplated by the Client is not undertaken within a period of
18 months following the submission of this report, or within the time frame understood by Wood to
be contemplated by the Client at the commencement of Wood’s assignment, and/or, if any changes
are made, for example, to the elevation, design or nature of any development on the site, its size and
configuration, the location of any development on the site and its orientation, the use of the site,
performance criteria and the location of any physical infrastructure, the conclusions and
recommendations presented herein should not be considered valid unless the impact of the said
changes is evaluated by Wood, and the conclusions of the report are amended or are validated in
writing accordingly.
Advancements in the practice of geotechnical engineering, engineering geology and hydrogeology
and changes in applicable regulations, standards, codes or criteria could impact the contents of the
report, in which case, a supplementary report may be required. The requirements for such a review
remain the sole responsibility of the Client or their agents.
Wood will not be liable to update or revise the report to take into account any events or emergent
circumstances or facts occurring or becoming apparent after the date of the report.
12. Limitations of visual inspections: Where conclusions and recommendations are given based on a
visual inspection conducted by Wood, they relate only to the natural or man-made structures, slopes,
etc. inspected at the time the site visit was performed. These conclusions cannot and are not
extended to include those portions of the site or structures, which were not reasonably available, in
Wood’s opinion, for direct observation.
Project No. EA16425 | 7/10/2020 Page 20 of 25
13. Limitations of site investigations: Site exploration identifies specific subsurface conditions only at
those points from which samples have been taken and only at the time of the site investigation. Site
investigation programs are a professional estimate of the scope of investigation required to provide a
general profile of subsurface conditions.
The data derived from the site investigation program and subsequent laboratory testing are
interpreted by trained personnel and extrapolated across the site to form an inferred geological
representation and an engineering opinion is rendered about overall subsurface conditions and their
likely behaviour with regard to the proposed development. Despite this investigation, conditions
between and beyond the borehole/test hole locations may differ from those encountered at the
borehole/test hole locations and the actual conditions at the site might differ from those inferred to
exist, since no subsurface exploration program, no matter how comprehensive, can reveal all
subsurface details and anomalies.
Final sub-surface/bore/profile logs are developed by geotechnical engineers based upon their
interpretation of field logs and laboratory evaluation of field samples. Customarily, only the final
bore/profile logs are included in geotechnical engineering reports.
Bedrock, soil properties and groundwater conditions can be significantly altered by environmental
remediation and/or construction activities such as the use of heavy equipment or machinery,
excavation, blasting, pile-driving or draining or other activities conducted either directly on site or on
adjacent terrain. These properties can also be indirectly affected by exposure to unfavorable natural
events or weather conditions, including freezing, drought, precipitation and snowmelt.
During construction, excavation is frequently undertaken which exposes the actual subsurface and
groundwater conditions between and beyond the test locations, which may differ from those
encountered at the test locations. It is recommended practice that Wood be retained during
construction to confirm that the subsurface conditions throughout the site do not deviate materially
from those encountered at the test locations, that construction work has no negative impact on the
geotechnical aspects of the design, to adjust recommendations in accordance with conditions as
additional site information is gained and to deal quickly with geotechnical considerations if they arise.
Interpretations and recommendations presented herein may not be valid if an adequate level of
review or inspection by Wood is not provided during construction.
14. Factors that may affect construction methods, costs and scheduling: The performance of rock and
soil materials during construction is greatly influenced by the means and methods of construction.
Where comments are made relating to possible methods of construction, construction costs,
construction techniques, sequencing, equipment or scheduling, they are intended only for the
guidance of the project design professionals, and those responsible for construction monitoring. The
number of test holes may not be sufficient to determine the local underground conditions between
test locations that may affect construction costs, construction techniques, sequencing, equipment,
scheduling, operational planning, etc.
Any contractors bidding on or undertaking the works should draw their own conclusions as to how
the subsurface and groundwater conditions may affect their work, based on their own investigations
and interpretations of the factual soil data, groundwater observations, and other factual information.
Project No. EA16425 | 7/10/2020 Page 21 of 25
15. Groundwater and Dewatering: Wood will accept no responsibility for the effects of drainage and/or
dewatering measures if Wood has not been specifically consulted and involved in the design and
monitoring of the drainage and/or dewatering system.
16. Environmental and Hazardous Materials Aspects: Unless otherwise stated, the information contained in
this report in no way reflects on the environmental aspects of this project, since this aspect is beyond
the Scope of Work and the Contract. Unless expressly included in the Scope of Work, this report
specifically excludes the identification or interpretation of environmental conditions such as
contamination, hazardous materials, wild life conditions, rare plants or archeology conditions that
may affect use or design at the site. This report specifically excludes the investigation, detection,
prevention or assessment of conditions that can contribute to moisture, mould or other microbial
contaminant growth and/or other moisture related deterioration, such as corrosion, decay, rot in
buildings or their surroundings. Any statements in this report or on the boring logs regarding
odours, colours, and unusual or suspicious items or conditions are strictly for informational
purposes
17. Sample Disposal: Wood will dispose of all uncontaminated soil and rock samples after 30 days
following the release of the final geotechnical report. Should the Client request that the samples
be retained for a longer time, the Client will be billed for such storage at an agreed upon rate.
Contaminated samples of soil, rock or groundwater are the property of the Client, and the Client
will be responsible for the proper disposal of these samples, unless previously arranged for with
Wood or a third party.