A REPORT TO ICON DUNFAIR LIMITED A GEOTECHNICAL INVESTIGATION … · 2018-02-07 · a report to...

A REPORT TO ICON DUNFAIR LIMITED

A GEOTECHNICAL INVESTIGATION

PROPOSED RESIDENTIAL DEVELOPMENT

2024 AND 2026 ALTONA ROAD AND 200 FINCH AVENUE

CITY OF PICKERING

REFERENCE NO. 1701-S023

MARCH 2017

DISTRIBUTION 3 Copies - Icon Dunfair Limited 1 Copy - Soil Engineers Ltd. (Oshawa) 1 Copy - Soil Engineers Ltd. (Toronto)

Reference No. 1701-S023 ii

TABLE OF CONTENTS

1.0 INTRODUCTION ................................................................................... 1

2.0 SITE AND PROJECT DESCRIPTION .................................................. 2

3.0 FIELD WORK ........................................................................................ 3

4.0 SUBSURFACE CONDITIONS .............................................................. 4

4.1 Topsoil ............................................................................................ 4 4.2 Earth Fill ......................................................................................... 5 4.3 Sandy Silt Till ................................................................................. 5 4.4 Sand ............................................................................................... 7 4.5 Silty Clay ........................................................................................ 8 4.6 Compaction Characteristics of the Revealed Soils ........................ 9

5.0 GROUNDWATER CONDITIONS ........................................................ 12 6.0 DISCUSSION AND RECOMMENDATIONS ...................................... 14

6.1 Foundations .................................................................................... 16 6.2 Engineered Fill ............................................................................... 19 6.3 Basement and Slab-On-Grade ........................................................ 22 6.4 Underground Services .................................................................... 23 6.5 Backfilling in Trenches and Excavated Areas ............................... 24 6.6 Sidewalk, Interlocking Stone Pavement and Landscaping ............ 26 6.7 Pavement Design ............................................................................ 27 6.8 Soil Parameters ............................................................................... 29 6.9 Excavation ...................................................................................... 29

7.0 LIMITATIONS OF REPORT ................................................................. 31

Reference No. 1701-S023 iii

TABLES

Table 1 - Estimated Water Content for Compaction ........................................ 10

Table 2- Groundwater Levels ........................................................................... 12

Table 3 - Founding Levels ................................................................................ 17

Table 4 - Pavement Design ............................................................................... 27

Table 5 - Soil Parameters .................................................................................. 29

Table 6 - Classification of Soils for Excavation ............................................... 30

DIAGRAM

Diagram 1- Frost Protection Measures (Foundations) ..................................... 19

ENCLOSURES Borehole Logs ...................................................................... Figures 1 to 9 Grain Size Distribution Graphs ........................................... Figures 10 and 11 Borehole Location Plan ....................................................... Drawing No. 1 Subsurface Profile ................................................................ Drawing No. 2

Reference No. 1701-S023 1

1.0 INTRODUCTION

In accordance with written authorization dated January 3, 2017, from

Mr. Stephen Brown of Icon Dunfair Limited, a geotechnical investigation was carried

out at 2024 and 2026 Altona Road and 200 Finch Avenue, in the City of Pickering,

for a Proposed Residential Development.

The purpose of the investigation was to reveal the subsurface conditions and to

determine the engineering properties of the disclosed soils for the design and

construction of the proposed project.

The geotechnical findings and resulting recommendations are presented in this

Report.


2.0 SITE AND PROJECT DESCRIPTION

The City of Pickering is situated on Iroquois (glacial lake) plain where, in places, the

glacial till stratigraphy has been partly eroded by the water action of the glacial lake

and filled with lacustrine sands, silts, clays and reworked till.

The site, approximately 2.19 hectares (5.4 acres) in area, is located at the northwest

quadrant of Altona Road and Finch Avenue in the City of Pickering. At the time of

investigation, the site is mostly covered with trees and vegetation, with existing

residences at the northeast and southwest portions. Near the west boundary of the

property, there is an existing scrap yard. The existing site gradient is relatively flat,

with a slight drop towards the southwest.

We understand that the site will be developed into a residential subdivision,

consisting of semi-detached houses and townhouse blocks. The new development

will be provided with municipal services, paved access roadway and parking spaces,

meeting urban standards.


3.0 FIELD WORK

The field work, consisting of 9 boreholes was performed on February 3, 2017 at the

locations shown on the Borehole Location Plan, Drawing No. 1. Borehole 1,

terminated at a depth of 0.6 m from the ground surface, was conducted for surface

soil sampling and limited for environmental assessment. Boreholes 6 and 7 were

terminated at a depth of 4.7 m due to refusal to augering on probable boulder. The

remaining boreholes were extended to depths of 6.3 to 6.7 m from grade.

Upon completion of drilling and soil sampling, four (4) monitoring wells were

installed one each in selected boreholes for Environmental Site Assessment.

The holes were advanced at intervals to the sampling depths by a track-mounted,

continuous-flight power-auger machine equipped for soil sampling. Standard

Penetration Tests, using the procedures described on the enclosed “List of

Abbreviations and Terms”, were performed at the sampling depths. The test results

are recorded as the Standard Penetration Resistance (or ‘N’ values) of the subsoil.

The relative density of the granular strata and the consistency of the cohesive strata

are inferred from the ‘N’ values. Split-spoon samples were recovered for soil

classification and laboratory testing.

The field work was supervised and the findings were recorded by a Geotechnical

Technician.

The elevation at each of the borehole locations was determined using Trimble 6000

GeoXH Global Navigation Satellite System survey equipment, which has an accuracy

of 10 cm.


4.0 SUBSURFACE CONDITIONS

Detailed descriptions of the encountered subsurface conditions are presented on the

Borehole Logs, comprising Figures 1 to 9, inclusive. The revealed stratigraphy is

plotted on the Subsurface Profile, Drawing No. 2, and the engineering properties of

the disclosed soils are discussed herein.

The investigation has revealed that beneath a topsoil veneer and a layer of earth fill,

the site is underlain by sandy silt till with occasional sand and silty clay layers.

4.1 Topsoil (Boreholes 1, 2, 3, 6, 7, 8 and 9)

The revealed topsoil thickness ranges between 25 cm and 60 cm. It is dark brown in

colour, indicating that it contains appreciable amounts of roots and humus. This

material is unstable and compressible under loads; therefore, the topsoil is considered

to be void of engineering value. Due to the humus content, the topsoil will generate

an offensive odour and may produce volatile gases under anaerobic conditions.

Therefore, the topsoil must not be buried below any structures or deeper than 1.2 m

below the exterior finished grade so it will not have an adverse impact on the

environmental well-being of the developed area.

Borehole 1, drilled for environmental assessment, was terminated at a depth of 0.6 m

from the prevailing ground surface.

Since the topsoil is considered void of engineering value, it can only be used for

general landscaping or landscape contouring purposes.


4.2 Earth Fill (All Boreholes)

The earth fill, consisting of silty sand with silty clay, gravel, occasional topsoil and

organics, was contacted. The earth fill in Boreholes 4 and 5 was found to contain

debris of wood, plastic and a mixture of topsoil. The earth fill extends to depths of

0.7 to 1.4 m below the prevailing ground surface.

The natural water content values of the earth fill range from 12% to 20%, with a

median of 14%, indicating that the earth fill is in a moist to wet condition.

The obtained ‘N’ values range from 1 to 22 blows per 30 cm of penetration,

indicating the relative density of the earth fill was non-uniform.

In using the earth fill for structural backfill, it must be subexcavated, inspected, sorted

free of debris, concentrated topsoil inclusions and deleterious materials, if any, and

properly recompacted in layers.

One must be aware that the samples retrieved from boreholes 10 cm in diameter may

not be truly representative of the geotechnical and environmental quality of the fill,

and do not indicate whether the topsoil beneath the earth fill was completely stripped.

This should be further assessed by laboratory testing and/or test pits.

4.3 Sandy Silt Till (All Boreholes)

The sandy silt till stratum was contacted at depths of 0.8 to 2.9 m below the

prevailing ground surface. It consists of a random mixture of soils; the particle sizes

range from clay to gravel, with the silt fraction exerting the dominant influence on its

soil properties. It structure is heterogeneous, showing a glacial deposit.


The obtained ‘N’ values range from 10 to over 50, with a median of 29 blows per

30 cm of penetration, indicating that the relative density of the sandy silt till is

compact to very dense, being generally compact.

The natural water content was determined and the results are plotted on the borehole

logs. These values range from 5% to 16%, with a median of 10%, indicating that the

silt till is in a damp to very moist condition, being generally moist.

Grain size analyses were performed on 3 representative samples; the results are

plotted on Figure 10.

Based on the above findings, the engineering properties of the silt till relating to the

project are given below:

• High frost susceptibility and soil-adfreezing potential.

• Low water erodibility.

• Moderately low permeability, with an estimated coefficient of permeability of

10-6 cm/sec, an average percolation rate of 60 min/cm, and runoff coefficients

of:

Slope

0% - 2% 0.15

2% - 6% 0.20

6% + 0.28

• A frictional soil, its shear strength is primarily derived from internal friction

and is augmented by cementation. Therefore, its strength is primarily soil

density dependent.

• In steep cuts, the till will be stable; however, under prolonged exposure,

localized sheet collapse will occur, particularly in the zone where wet sand and

silt layers are prevalent.


• A poor pavement-supportive material with an estimated CBR value of 5%.

• Moderate corrosivity to buried metal, with an estimated electrical resistivity of

4000 to 4500 ohm·cm.

4.4 Sand (Boreholes 4, 5, 8 and 9)

The sand deposit was contacted below the earth fill. It is fine grained or fine to

medium, with silt and occasional gravel.

The obtained ‘N’ values range from 11 to 31 blows per 30 cm of penetration,

indicating that the relative density of the sand deposit is compact to dense.

The natural water content was determined and the results are plotted on the borehole

logs. These values range from 7% to 21%, with a median of 17%, indicating that the

sand is in a damp to wet condition, being generally wet or saturated.

A grain size analysis was performed on 1 representative sample; the result is plotted

on Figure 11.

Based on the above findings, the deduced engineering properties pertaining to the

project are given below:

• Moderate frost susceptibility and low soil-adfreezing potential.

• High water erodibility.

• Pervious, with an estimated coefficient of permeability of 10-3 cm/sec, an

average percolation rate of 10 min/cm, and runoff coefficients of:


Slope

0% - 2% 0.04

2% - 6% 0.09

6% + 0.13

• A frictional soil, the shear strength is primarily derived from internal friction;

therefore, the strength is density dependent. Due to the dilatancy, the shear

strength of the wet sand is susceptible to impact disturbance; i.e., the

disturbance will induce a build-up of pore pressure within the soil mantle,

resulting in soil dilation and a reduction of shear strength.

• The sand will slough if it is wet and run with water seepage and the bottom

will boil under a piezometric head of 0.4 m.

• Fair pavement-supportive material, with an estimated CBR value of 8%.

• Moderately low corrosivity to buried metal, with an estimated electrical

resistivity of 6000 ohm·cm.

4.5 Silty Clay (Boreholes 4 and 5)

The silty clay was contacted underlying the sand deposit. It contains occasional

seams of silty sand.

The obtained ‘N’ values are 7 and 13 blows per 30 cm of penetration, indicating the

consistency of the clay is firm to stiff.

The natural water content was determined at 19% and 21%, indicating a very moist

condition.

The deduced engineering properties pertaining to the project are given below:

• High frost susceptibility and soil-adfreezing potential.


• The laminated silty sand layers are water erodible.

• Low permeability, with an estimated coefficient of permeability of 10-7 cm/sec,

an average percolation rate of more than 80 min/cm, and runoff coefficients of:

Slope

0% - 2% 0.15

2% - 6% 0.20

6% + 0.28

• A cohesive-frictional soil, its shear strength is derived from consistency and

augmented by the internal friction of the silt. Its shear strength is moisture

dependent, due to the dilatancy of the silt, the overall shear strength of the silty

clay is susceptible to impact disturbance; i.e., the disturbance will induce a

build-up of pore pressure within the soil mantle, resulting in soil dilation and a

reduction of shear strength.

• In steep cuts, the weathered clay with high moisture will slough readily and a

cut face in the sound clay may collapse as the wet silt slowly sloughs.

• A very poor pavement-supportive material, with an estimated CBR value of

3% or less.

• Moderately high to moderate corrosivity to buried metal, with an estimated

electrical resistivity of 3000 to 4000 ohm⋅cm.

4.6 Compaction Characteristics of the Revealed Soils

The obtainable degree of compaction is primarily dependent on the soil moisture and,

to a lesser extent, on the type of compactor used and the effort applied.

As a general guide, the typical water content values of the revealed soils for Standard

Proctor compaction are presented in Table 1.


Table 1 - Estimated Water Content for Compaction

Soil Type Determined Natural Water Content (%)

Water Content (%) for Standard Proctor Compaction

100% (optimum) Range for 95% or +

Existing Earth Fill 12 to 20 (median 14) 12 8 to 15

Sandy Silt Till 5 to 16 (median 10) 13 8 to 16

Sand 7 to 21 (median 17) 10 6 to 13

Silty Clay 19 and 21 17 13 to 21

The above values show that most of the on-site material is suitable for 95% or +

Standard Proctor compaction. However, part of the earth fill and the saturated sand

are too wet and will require aeration prior to structural compaction. Aeration can be

achieved by spreading them thinly on the ground in the dry, warm weather or the

saturated sand can be stockpiled to drain the excess water prior to structural

compaction.

The till and clay should be compacted using a heavy-weight, kneading-type roller.

The sand can be compacted by a smooth roller with or without vibration, depending

on the water content of the soils being compacted. The lifts for compaction should be

limited to 20 cm, or to a suitable thickness as assessed by test strips performed by the

equipment which will be used at the time of construction.

One should be aware that with considerable effort, a 90%± Standard Proctor

compaction of the wet silty sand is achievable. Further densification is prevented by

the pore pressure induced by the compactive effort; however, large random voids will

have been expelled and, with time, the pore pressure will dissipate and the percentage


of compaction will increase. There are many cases on record where after a few

months of rest, the density of the compacted mantle had increased to over 95% of its

maximum Standard Proctor dry density.

When compacting the till or clay on the dry side of the optimum, the compactive

energy will frequently bridge over the chunks in the soil and be transmitted laterally

into the soil mantle. Therefore, the lifts of this soil must be limited to 20 cm or less

(before compaction). It is difficult to monitor the lifts of backfill placed in deep

trenches; therefore, it is preferable that the compaction of backfill at depths over

1.0 m below the road subgrade be carried out on the wet side of the optimum. This

would allow wider latitude of lift thickness.

If the compaction of the soils is carried out with the water content within the range

for 95% Standard Proctor dry density but on the wet side of the optimum, the surface

of the compacted soil mantle will roll under the dynamic compactive load. This is

unsuitable for pavement construction since each component of the pavement structure

is to be placed under dynamic conditions which will induce the rolling action of the

subgrade surface and cause structural failure of the new pavement. The slab-on-

grade, foundations for buildings and utilities will be placed on a subgrade which will

not be subjected to impact loads. Therefore, the structurally compacted soil mantle

with the water content on the wet side or dry side of the optimum will provide an

adequate subgrade for the construction.

The presence of boulders in the till will prevent transmission of the compactive

energy into the underlying material to be compacted. If an appreciable amount of

boulders over 15 cm in size mixed with the material, it must either be sorted or must

not be used for structural backfill and/or construction of engineered fill.


5.0 GROUNDWATER CONDITIONS

The boreholes and monitoring wells were checked for the presence of groundwater

and the occurrence of cave-in upon their completion and on February 10, 2017. The

levels are plotted on the Borehole Logs and listed in Table 2.

Table 2- Groundwater Levels

BH No. Ground El.

(m)

Borehole Depth

(m)

Well Installed

Depth (m)

Measured Groundwater/

Cave-in* Level On Completion

Groundwater Level on

February 10, 2017

Depth (m)

El. (m)

Depth (m)

El. (m)

2 139.4 6.3 - 1.8 137.6 - -

3 139.4 6.6 - 1.2/1.5* 138.2/137.9* - -

4 139.9 6.7 5.2 3.7/4.0* 136.2/135.9* 2.7 137.2

5 139.0 6.7 5.5 3.7/4.0* 135.3/135.0* 1.3 137.7

6 138.9 4.7 - 0.9* 138.0* - -

7 138.6 4.7 3.7 0.8 137.8 0.2 138.4

8 138.5 6.3 - 0.9/1.2* 137.6/137.3* - -

9 138.1 6.6 4.0 1.2/1.4* 136.9/136.7* 0.9 137.2

Groundwater and/or cave-in of boreholes were recorded at depths of 0.8 to 4.0 m

below the prevailing ground surface, upon completion of drilling. On February 10,

2017, the stabilized groundwater level was recorded at depths of 0.2 to 2.7 m from

the ground surface, or El. 138.4 to 137.2 m in the monitoring wells.

The detected groundwater is likely due to infiltrated precipitation trapped in the earth

fill or in the sand and silt layers rendering perched groundwater above the strata of

low permeable clay or till. It is expected to fluctuate with the seasons.


In excavation, the groundwater yield from the clay and till, due to their low

permeability, is expected to be small and limited, while the yield from the saturated

sand is expected to be moderate to appreciable and likely persistent. The water can

be collected to a sump and removed by conventional pumping.


6.0 DISCUSSION AND RECOMMENDATIONS

The investigation has disclosed that beneath a topsoil veneer, 25 to 60 cm in

thickness, and a layer of earth fill, extending to depths of 0.7 to 1.4 m, the site is

underlain by compact to very dense sandy silt till with occasional compact to dense

sand and firm to stiff silty clay layers.

Groundwater and/or cave-in of boreholes were recorded at depths of 0.8 to 4.0 m

below the prevailing ground surface upon completion of drilling. Stabilized

groundwater levels in the monitoring wells were recorded at depths of 0.2 to 2.7 m

from the ground surface, or El. 138.4 to 137.2 m on February 10, 2017. The detected

groundwater is likely due to infiltrated precipitation trapped in the earth fill or in the

sand layers rendering perched groundwater above the strata of low permeable clay or

till. It is expected to fluctuate with the seasons.

We understand that the existing structures will be demolished and the site will be

regraded for the development of a residential subdivision. The geotechnical findings

which warrant special consideration are presented below:

1. The topsoil is void of engineering value, unsuitable for engineering

applications. Due to its humus content, the topsoil will generate an offensive

odour and may produce volatile gases under anaerobic conditions. For the

environmental as well as the geotechnical well-being of the future

development, the topsoil should not be buried below any structures or deeper

than 1.2 m below the external finished grade.

2. Due to the unknown history of the earth fill, and the presence of topsoil and

other deleterious materials, the fill is unsuitable for supporting any structure

sensitive to movement. In using the fill for structural backfill, or in pavement

or slab-on-grade construction, it should be subexcavated, inspected, sorted free


of debris, concentrated topsoil inclusions and any deleterious materials, and

properly recompacted in layers. If it is impractical to sort the debris, topsoil

and other deleterious material from the fill, the fill must be wasted.

3. The sound natural soil below the topsoil and earth fill is suitable for normal

spread and strip footing construction for the proposed houses and townhouse

blocks.

4. The footing subgrade must be inspected by either a geotechnical engineer, or a

geotechnical technician under the supervision of a geotechnical engineer, or by

a building inspector who has geotechnical experience, to ensure that its

condition is compatible with the design of the foundation.

5. Where cut and fill is necessary for site grading, substantial savings can be

realized by placing the fill in an engineered manner suitable for foundation,

underground services and access roadway construction. This must, however,

be properly planned and implemented during the site grading stage.

6. In the west portion of the site where saturated sand is present, the basement

structure should be constructed above the saturation level unless the

submerged portion is waterproofed, otherwise, dewatering from the foundation

subdrains will be required. The stabilized groundwater level will be specified

in the hydrogeological assessment report.

7. The subgrade for the underground services should consist of properly

compacted inorganic earth fill or sound natural soil. A Class ‘B’ bedding is

recommended for the underground services construction. The bedding

material should consist of compacted 20-mm Crusher-Run Limestone, or

equivalent. In areas where the subgrade is saturated, a Class ‘A’ bedding

should be considered.

8. Curb subdrains will be required for road construction.

9. Excavation should be carried out in accordance with Ontario Regulation

213/91.


10. The till contains occasional cobbles and boulders. Boulders over 15 cm in size

must not be used for structural backfill and/or construction of engineered fill.

Excavation into the till containing boulders will require extra effort and the use

of a heavy-duty backhoe.

The recommendations appropriate for the project described in Section 2.0 are

presented herein. One must be aware that the subsurface conditions may vary

between boreholes. Should this become apparent during construction, a geotechnical

engineer must be consulted to determine whether the following recommendations

require revision.

6.1 Foundations

Based on the borehole findings, normal spread and strip footings of the proposed

structures must be placed below the earth fill and onto the sound, natural soil. As a

general guide, the recommended soil pressures for use in the design of conventional

footings, together with the corresponding suitable founding levels, are presented in

Table 3.


Table 3 - Founding Levels

Borehole No.

Recommended Maximum Allowable Soil Pressure (SLS)/ Factored Ultimate Soil Bearing Pressure (ULS) and

Suitable Founding Level

100 kPa (SLS) 160 kPa (ULS)



Depth (m) El. (m) Depth (m) El. (m) Depth (m)

El. (m)

2 - - 1.4 or + 138.0 or - 2.4 or + 137.0 or -

3 - - 1.4 or + 138.0 or - 2.4 or + 137.0 or -

4 1.6 or + 138.3 or - 4.8 or + 135.1 or - - -

5 1.0 or + 138.0 or - 2.4 or + 136.6 or - - -

6 1.2 or + 137.7 or - - - 2.4 or + 136.5 or -

7 - - 1.0 or + 137.6 or - 2.4 or + 136.2 or -

8 - - 1.0 or + 137.5 or - 3.2 or + 135.3 or -

9 1.0 or + 137.1 or - 3.2 or + 134.9 or - - -

Where cut and fill is required for site grading, it is generally more practical and

economical to place an engineered fill suitable for a Maximum Allowable Soil

Pressure (SLS) of 100 kPa for normal footing construction. The requirements and

procedures for engineered fill construction are discussed in Section 6.2.

The recommended soil pressure (SLS) incorporates a safety factor of 3. The total and

differential settlements of the footings are estimated to be 25 mm and 15 mm,

respectively.


The footings must meet the requirements specified in the latest version of the Ontario

Building Code. As a guide, the structure should be designed to resist an earthquake

force using Site Classification ‘D’ (stiff soil).

In the west portion of the site, where a saturated sand stratum is present, the basement

structure should be constructed above the saturated level unless the submerged

portion is waterproofed, otherwise, permanent dewatering from the foundation

subdrains will be required. The subdrains will consist of perimeter drains and under-

floor drains, connecting into sump pits where water can be removed by gravity or

pumping. All the subdrains should be encased in a fabric-filter to protect them

against blockage by silting.

If groundwater is encountered in the footing excavation, or the subgrade is found to

be wet, the subgrade should be protected by a concrete mud-slab placed immediately

after exposure. This will prevent construction disturbance and costly rectification.

Due to the presence of earth fill, the footing subgrade must be inspected by either a

geotechnical engineer, or by a geotechnical technician under the supervision of a

geotechnical engineer, or a building inspector who has geotechnical experience, to

assess its suitability for bearing the designed foundations.

Foundations exposed to weathering or in unheated areas should be protected against

frost action by a minimum of 1.2 of earth cover.

The on site soils are high in soil-adfreezing potential. If they are used for the

foundation backfill, the foundation walls should be constructed in concrete and

shielded by a polyethylene slip-membrane for protection against soil adfreezing. The

recommended measures are schematically illustrated below in Diagram 1.


Diagram 1- Frost Protection Measures (Foundations)

Vapour Barrier

Slip-Membrane (Closed End Up)Folded Heavy Polyethylene

Covered with 19-mm Clear StoneSubdrain Encased in Fabric Filter

1.2m

Floor Subdrain

(Subject to

Conditions)Groundwater

The membrane will allow vertical movement of the heaving soil (due to frost)

without imposing structural distress on the foundations. The external grading should

be such that runoff is directed away from the foundation.

6.2 Engineered Fill

It is generally more economical to place engineered fill for normal footing,

underground services and pavement construction. The engineering requirements for

a certifiable fill for pavement construction, municipal services, slab-on-grade, and

footings designed with a Maximum Allowable Soil Pressure (SLS) of 100 kPa and a

Factored Ultimate Soil Bearing Pressure (ULS) of 160 kPa are presented below:

1. All of the topsoil, earth fill and organics must be removed and the subgrade

must be inspected and proof-rolled prior to any fill placement. The weathered

soils must be subexcavated, sorted and recompacted and the subgrade must be

inspected and proof-rolled prior to any fill placement.

2. Inorganic soils must be used, and they must be uniformly compacted in lifts

20 cm thick to 98% or + of their maximum Standard Proctor dry density up to

1.4 m


the proposed finished grade and/or slab-on-grade subgrade. The soil moisture

must be properly controlled on the wet side of the optimum.

3. If imported fill is to be used, the hauler is responsible for its environmental

quality and must provide a document to certify that the material is free of

hazardous contaminants.

4. If the residential units’ foundations are to be built soon after the fill placement,

the densification process for the engineered fill must be increased to 100% of

the maximum Standard Proctor compaction.

5. If the engineered fill is to be left over the winter months, adequate earth cover,

or equivalent, must be provided for protection against frost action.

6. The engineered fill must extend over the entire graded area; the engineered fill

envelope and the finished elevations must be clearly and accurately defined in

the field, and they must be precisely documented by qualified surveyors.

Foundations partially on engineered fill must be reinforced by two

15-mm steel reinforcing bars in the footings and upper section of the

foundation walls, or be designed by a structural engineer, to properly distribute

the stress induced by the abrupt differential settlement (estimated to be

15± mm) between the natural soils and engineered fill.

7. The engineered fill must not be placed during the period from late November

to early April, when freezing ambient temperatures occur either persistently or

intermittently. This is to ensure that the fill is free of frozen soils, ice or snow.

8. Where the ground is wet due to subsurface water seepage, an appropriate

subdrain scheme must be implemented prior to the fill placement.

9. Where the fill is to be placed on sloping ground steeper than 1 vertical:

3 horizontal, the face of the sloping ground must be flattened to 3 + so that it is

suitable for safe operation of the compactor and the required compaction can

be obtained.


10. The fill operation must be inspected on a full-time basis by a technician under

the direction of a geotechnical engineer.

11. The footing and underground services subgrade must be inspected by the

geotechnical consulting firm that inspected the engineered fill placement. This

is to ensure that the foundations are placed within the engineered fill envelope,

and the integrity of the fill has not been compromised by interim construction,

environmental degradation and/or disturbance by the footing excavation.

12. Any excavation carried out in certified engineered fill must be reported to the

geotechnical consultant who supervised the fill placement in order to

document the locations of the excavation and/or to supervise reinstatement of

the excavated areas to engineered fill status. If construction on the engineered

fill does not commence within a period of 2 years from the date of

certification, the condition of the engineered fill must be assessed for

re-certification.

13. Despite stringent control in the placement of the engineered fill, variations in

soil type and density may occur in the engineered fill. Therefore, the strip

footings and the upper section of the foundation walls constructed on the

engineered fill may require continuous reinforcement with steel bars,

depending on the uniformity of the soils in the engineered fill and the

thickness of the engineered fill underlying the foundations. Should the

footings and/or walls require reinforcement, the required number and size of

reinforcing bars must be assessed by considering the uniformity as well as the

thickness of the engineered fill beneath the foundations. In sewer

construction, the engineered fill is considered to have the same structural

proficiency as a natural inorganic soil.


6.3 Basement and Slab-On-Grade

The soil parameters outlined in Section 6.8 can be used for calculating the lateral

earth pressure imposed on the basement walls. In order to prevent water ponding

against the perimeter walls and wetting the basement, perimeter subdrains should be

installed and the walls should be dampproofed or waterproofed. If groundwater

seepage is encountered during basement excavation, the conditions must be further

assessed and under-floor subdrains consisting of filter-sleeved weepers connecting

into a positive outlet will be required.

The subgrade for slab-on-grade construction should comprise sound natural soils or

properly compacted earth fill. The existing topsoil must be removed. Any soft or

loose areas detected must be subexcavated and replaced with inorganic fill,

compacted to at least 98% of its maximum Standard Proctor dry density prior to

placement of the granular base.

If the subgrade has been loosened due to construction traffic, it must be proof-rolled

before placement of the granular base.

The slab should be constructed on a granular base 20 cm thick, consisting of

20-mm Crusher-Run Limestone, or equivalent, compacted to 100% of its maximum

Standard Proctor dry density.

A Modulus of Subgrade Reaction of 25 MPa/m can be used for the design of the floor

slab.


The ground around the buildings must be graded to direct water away from the

structure to minimize the frost heave phenomenon generally associated with the

disclosed soils.

6.4 Underground Services

The subgrade for the underground services should consist of sound natural soil or

properly compacted, organic-free earth fill. Where badly weathered or loose soils are

encountered, they should be subexcavated and replaced with the bedding material

compacted to at least 95% or + of its Standard Proctor compaction.

A Class ‘B’ bedding is generally recommended for the underground services

construction. The bedding material should consist of compacted 20-mm Crusher-Run

Limestone, or equivalent. In areas where the subgrade is saturated, a Class ‘A’

bedding should be considered or anti-seepage collars will be required.

In order to prevent pipe floatation when the sewer trench is deluged with water, a soil

cover at least equal in thickness to the diameter of the pipe should be in place at all

times after completion of the pipe installation.

Openings to subdrains and catch basins should be shielded with a fabric filter to

prevent blockage by silting.

Sewer excavation must be sloped at 1 vertical:1 or + horizontal for stability.

Alternatively, a trench box can also be used for the construction of the sewer.

The water main should be protected against corrosion. In determining the mode of

protection, an electrical resistivity of 3000 ohm∙cm should be used. This, however,

should be confirmed by testing the soil along the water main alignment at the time of

sewer construction.


6.5 Backfilling in Trenches and Excavated Areas

The on-site inorganic soil is mostly suitable for trench backfill. However, the earth

fill should be sorted free of any topsoil, deleterious materials and foreign matter prior

to the backfilling. In addition, most of the existing earth fill and saturated sand are

wet and will require aeration or mixing with drier soils prior to structural compaction.

The sandy silt till should be sorted free of boulders, if encountered, for backfilling.

The backfill in the trenches should be compacted to at least 95% of its maximum

Standard Proctor dry density and increased to 98% or + below the floor slab. In the

zone within 1.0 m below the road subgrade, the materials should be compacted with

the water content 2% to 3% drier than the optimum, and the compaction should be

increased to at least 98% of the respective maximum Standard Proctor dry density.

This is to provide the required stiffness for pavement construction. In the lower zone,

the compaction should be carried out on the wet side of the optimum; this allows

wider latitude of lift thickness. Backfill below any slab-on-grade which is sensitive

to settlement must be compacted to at least 98% of its maximum Standard Proctor

dry density.

In normal construction practice, the problem areas of settlement largely occur

adjacent to manholes, catch basins, services crossings, foundation walls and columns.

In areas which are inaccessible to a heavy compactor, imported sand backfill should

be used. Unless compaction of the backfill is carefully performed, the interface of the

native soils and the sand backfill will have to be flooded for a period of several days.

The narrow trenches for services crossings should be cut at 1 vertical:

2 or + horizontal so that the backfill can be effectively compacted. Otherwise, soil

arching will prevent the achievement of proper compaction. The lift of each backfill


layer should either be limited to a thickness of 20 cm, or the thickness should be

determined by test strips.

One must be aware of the possible consequences during trench backfilling and

exercise caution as described below:

• When construction is carried out in freezing winter weather, allowance should

be made for these following conditions. Despite stringent backfill monitoring,

frozen soil layers may inadvertently be mixed with the structural trench

backfill. Should the in situ soils have a water content on the dry side of the

optimum, it would be impossible to wet the soils due to the freezing condition,

rendering difficulties in obtaining uniform and proper compaction.

Furthermore, the freezing condition will prevent flooding of the backfill when

it is required, such as in a narrow vertical trench section, or when the trench

box is removed. The above will invariably cause backfill settlement that may

become evident within 1 to several years, depending on the depth of the trench

which has been backfilled.

• In areas where the underground services construction is carried out during the

winter months, prolonged exposure of the trench walls will result in frost

heave within the soil mantle of the walls. This may result in some settlement

as the frost recedes, and repair costs will be incurred prior to final surfacing of

the new pavement and the slab-on-grade.

• To backfill a deep trench, one must be aware that future settlement is to be

expected, unless the side of the cut is flattened to at least 1 vertical:

1.5+ horizontal, and the lifts of the fill and its moisture content are stringently

controlled; i.e., lifts should be no more than 20 cm (or less if the backfilling

conditions dictate) and uniformly compacted to achieve at least 95% of the


maximum Standard Proctor dry density, with the moisture content on the wet

side of the optimum.

• It is often difficult to achieve uniform compaction of the backfill in the lower

vertical section of a trench which is an open cut or is stabilized by a trench

box, particularly in the sector close to the trench walls or the sides of the box.

These sectors must be backfilled with sand. In a trench stabilized by a trench

box, the void left after the removal of the box will be filled by the backfill. It

is necessary to backfill this sector with sand, and the compacted backfill must

be flooded for 1 day, prior to the placement of the backfill above this sector,

i.e., in the upper sloped trench section. This measure is necessary in order to

prevent consolidation of inadvertent voids and loose backfill which will

compromise the compaction of the backfill in the upper section. In areas

where groundwater movement is expected in the sand fill mantle, anti-seepage

collars should be provided.

6.6 Sidewalk, Interlocking Stone Pavement and Landscaping

Due to the high frost susceptibility of on site soils, heaving of the pavement and

sidewalk is expected to occur during the cold weather.

Interlocking stone pavement, slab-on-grade and landscaping structures in areas which

are sensitive to frost-induced ground movement, such as in front of building

entrances, must be constructed on a free-draining, non-frost-susceptible granular

material such as Granular ‘B’. This material must extend to at least 0.3 to 1.2 m

below the slab or pavement surface, depending on the degree of tolerance of ground

movement, and be provided with positive drainage, such as weeper subdrains

connected to manholes or catch basins. Alternatively, the landscaping structures,

slab-on-grade and interlocking stone pavement should be properly insulated with

50-mm Styrofoam, or equivalent.


The grading around structures must be such that it directs runoff away from the

structures.

6.7 Pavement Design

The on site soils are poor to fair pavement-supportive materials; the recommended

pavement designs for the proposed roads are presented in Table 4.

Table 4 - Pavement Design

Course Thickness (mm) OPS Specifications

Asphalt Surface 40 HL-3

Asphalt Binder 60 HL-8

Granular Base 150 OPSS Granular ‘A’ or equivalent

Granular Sub-base 350 OPSS Granular ‘B’ or equivalent

In preparation of the subgrade, the topsoil must be removed. The final subgrade must

be proof-rolled. Any soft subgrade as identified should be subexcavated and replaced

by properly compacted, organic-free earth fill.

In the zone within 1.0 m below the pavement subgrade, the backfill should be

compacted to at least 98% of its maximum Standard Proctor dry density, with the

water content 2% to 3% drier than the optimum. In the lower zone, a 95% or +

Standard Proctor compaction is considered adequate.

All the granular bases should be compacted to their maximum Standard Proctor dry

density.


The pavement subgrade will suffer a strength regression if water is allowed to

saturate the mantle. The following measures should, therefore, be incorporated in the

construction procedures and pavement design:

• If the pavement construction does not immediately follow the trench

backfilling, the subgrade should be properly crowned and smooth-rolled to

allow interim precipitation to be properly drained.

• Areas adjacent to the pavement should be properly graded to prevent ponding

of large amounts of water during the interim construction period.

• Curb subdrains will be required. The subdrains should consist of filter-sleeved

weepers to prevent blockage by silting. The subdrains should be installed to a

depth of at least 0.4 m below the pavement subgrade surface and then

backfilled with free-draining granular material.

• If the pavement is to be constructed during wet seasons and extensively soft

subgrade occurs, the granular sub-base should be thickened in order to

compensate for the inadequate strength of the subgrade. This can be assessed

during construction.

In the paved areas, catch basins should be provided; they should drain into the storm

sewer or a suitable outlet. The trenches for the connections to the catch basins should

be backfilled with free-draining granular material such as Granular ‘B’, and filter-

sleeved weeper stubs should be installed at the manholes and catch basins into the

granular backfill. This will allow water in the trenches to drain into the storm sewers.


6.8 Soil Parameters

The recommended soil parameters for the project design are given in Table 5.

Table 5 - Soil Parameters

Unit Weight and Bulk Factor Unit Weight (kN/m3)

Estimated Bulk Factor

Bulk Submerged Loose Compacted

Earth Fill 20.5 11.5 1.20 0.98

Sand 20.0 10.0 1.25 1.00

Silty Clay 21.0 11.5 1.30 1.00

Sandy Silt Till 22.5 12.5 1.33 1.05

Lateral Earth Pressure Coefficients

Active Ka

At Rest K0

Passive Kp

Compacted Earth Fill/Silty Clay 0.45 0.60 2.20

Sand 0.35 0.52 2.80

Sandy Silt Till 0.30 0.46 3.30

6.9 Excavation

Excavation should be carried out in accordance with Ontario Regulation 213/91.

For excavation purposes, the types of soils are classified in Table 6.


Table 6 - Classification of Soils for Excavation

Material Type

Sound Silty Clay, Sandy Silt Till 2

Earth Fill, drained Sand 3

Saturated Sand 4

In excavation, the groundwater yield from the clay and till, due to their low

permeability, is expected to be small and limited, while the yield from the sand is

expected to be moderate to appreciable and likely persistent. Any groundwater

seepage can be collected in to sumps and removed by conventional pumping.

Prospective contractors must assess the in situ subsurface conditions prior to

excavation by digging test pits to at least 0.5 m below the sewer subgrade. These test

pits should be allowed to remain open for a period of at least 4 hours to assess the

trenching conditions.

LIST OF ABBREVIATIONS AND DESCRIPTION OF TERMS The abbreviations and terms commonly employed on the borehole logs and figures, and in the text of the report, are as follows: SAMPLE TYPES

AS Auger sample CS Chunk sample DO Drive open (split spoon) DS Denison type sample FS Foil sample RC Rock core (with size and percentage

recovery) ST Slotted tube TO Thin-walled, open TP Thin-walled, piston WS Wash sample PENETRATION RESISTANCE

Dynamic Cone Penetration Resistance:

A continuous profile showing the number of blows for each foot of penetration of a 2-inch diameter, 90° point cone driven by a 140-pound hammer falling 30 inches. Plotted as ‘ • ’

Standard Penetration Resistance or ‘N’ Value:

The number of blows of a 140-pound hammer falling 30 inches required to advance a 2-inch O.D. drive open sampler one foot into undisturbed soil. Plotted as ‘’

WH Sampler advanced by static weight PH Sampler advanced by hydraulic pressure PM Sampler advanced by manual pressure NP No penetration

SOIL DESCRIPTION

Cohesionless Soils:

‘N’ (blows/ft) Relative Density

0 to 4 very loose 4 to 10 loose

10 to 30 compact 30 to 50 dense

over 50 very dense

Cohesive Soils:

Undrained Shear Strength (ksf) ‘N’ (blows/ft) Consistency

less than 0.25 0 to 2 very soft 0.25 to 0.50 2 to 4 soft 0.50 to 1.0 4 to 8 firm 1.0 to 2.0 8 to 16 stiff 2.0 to 4.0 16 to 32 very stiff

over 4.0 over 32 hard

Method of Determination of Undrained Shear Strength of Cohesive Soils:

x 0.0 Field vane test in borehole; the number denotes the sensitivity to remoulding

Laboratory vane test

Compression test in laboratory

For a saturated cohesive soil, the undrained shear strength is taken as one half of the undrained compressive strength

METRIC CONVERSION FACTORS 1 ft = 0.3048 metres 1 inch = 25.4 mm 1lb = 0.454 kg 1ksf = 47.88 kPa

0.0

(No geotechnical data retained)

This borehole was sampled for the environmental scope of work.

8

7

6

5

4

3

2

1

00

1LOG OF BOREHOLE NO.:1701-S023JOB NO.:

Proposed Residential DevelopmentPROJECT DESCRIPTION:

2024 and 2026 Altona Road and 200 Finch Avenue City of Pickering

PROJECT LOCATION:

1FIGURE NO.:

ShovelMETHOD OF BORING:

February 3, 2017DRILLING DATE:

Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)

Atterberg LimitsPL LL

WA

TER

LE

VE

L

Dynamic Cone (blows/30 cm)

9070503010

Penetration Resistance(blows/30 cm)

9070503010

Shear Strength (kN/m2)

20015010050

Moisture Content (%)40302010

Soil Engineers Ltd.1 of 1Page:

0.0

0.3

1.2

6.3

139.1

138.2

133.1

END OF BOREHOLE

30 cm TOPSOIL

EARTH FILL

brown silty sand, some gravel, cobble and rootlets

Grey, compact to very dense

SANDY SILT TILL

a trace to some clay and gravel occ. sand and clay seams and layers, cobbles and boulders

10

15

21

50/15

60/15

50/15

55/15

DO

DO

DO

DO

DO

DO

DO

1A

1B

2

3

4

5

6

7

8

7

6

5

4

3

2

1

0 4620

16

7

6

7

6

7W

.L. @

El.

137.

6 m

on

com

plet

ion

139.4




PROJECT LOCATION:

2FIGURE NO.:

Flight-AugerMETHOD OF BORING:


Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)


WA

TER

LE

VE

L


9070503010


9070503010


20015010050



0.0

0.3

1.2

6.6

139.1

138.2

132.8

END OF BOREHOLE

30 cm TOPSOIL

EARTH FILL

brown silty sand, some clay and gravel, occ. cobble and organics


SANDY SILT TILL


4

22

16

50/15

53/15

74

63

DO

DO

DO

DO

DO

DO

DO

1A

1B

2

3

4

5

6

7

8

7

6

5

4

3

2

1

0 2213

13

11

5

6

7

7

W.L

. @ E

l. 13

8.2

m o

n co

mpl

etio

nC

ave-

in @

El.

137.

9 m

on

com

plet

ion

139.4




PROJECT LOCATION:

3FIGURE NO.:



Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)


WA

TER

LE

VE

L


9070503010


9070503010


20015010050



0.0

1.4

2.2

2.5

6.7

138.5

137.7

137.4

133.2

END OF BOREHOLE

Installed 50 mm Ø monitoring well to 5.2 m. (3.1 m screen) Sand backfill from 1.6 m to 5.2 m. Bentonite seal from 0.2 m to 1.6 m. Provided with monument protective casing.

EARTH FILL

dark brown to brown sand and gravel some debris of wood and plastic occ. topsoil and organics

Brown, compact

SAND

fine grained, some siltBrown, stiff

SILTY CLAY occ. seams of silty sandGrey, compact

SANDY SILT TILL


9

10

17

13

10

12

22

16

28

DO

DO

DO

DO

DO

DO

DO

DO

DO

1

2

3

4

5

6

7

8

9

8

7

6

5

4

3

2

1

0 12

13

7

19

12

11

11

10

10 W.L

. @ E

l. 13

6.2

m o

n co

mpl

etio

nC

ave-

in @

El.

135.

9 m

on

com

plet

ion

W.L

. @ E

l. 13

7.2

m o

n Fe

brua

ry 1

0, 2

017

139.9




PROJECT LOCATION:

4FIGURE NO.:



Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)


WA

TER

LE

VE

L


9070503010


9070503010


20015010050



0.0

0.8

1.7

2.2

6.7

138.2

137.3

136.8

132.3

END OF BOREHOLE


EARTH FILL

dark brown silty sand mixed with topsoil

Brown, compact

SAND

fine grained, some silt

Brown, firm

SILTY CLAY occ. seams of silty sandCompact to dense

SANDY SILT TILL


browngrey

8

11

7

20

16

26

25

35

29

DO

DO

DO

DO

DO

DO

DO

DO

DO

1

2

3

4

5

6

7

8

9

8

7

6

5

4

3

2

1

0 19

17

21

16

10

9

9

11

8 W.L

. @ E

l. 13

5.3

m o

n co

mpl

etio

nC

ave-

in @

El.

135.

0 m

on

com

plet

ion

W.L

. @ E

l. 13

7.7

m o

n Fe

brua

ry 1

0, 2

017

139




PROJECT LOCATION:

5FIGURE NO.:



Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)


WA

TER

LE

VE

L


9070503010


9070503010


20015010050



0.0

0.3

1.0

4.7

138.6

137.9

134.2

END OF BOREHOLE

Refusal to augering on probable boulder

30 cm TOPSOIL

EARTH FILL dark brown to brown sand and gravel, some silt, trace of organics


SANDY SILT TILL


10

20

12

50/15

53/15

50/15

DO

DO

DO

DO

DO

DO

1A

1B

2A2B

3

4

5

6

8

7

6

5

4

3

2

1

0 2215

1311

11

7

7

6

Cav

e-in

@ E

l. 13

8.0

m o

n co

mpl

etio

n

138.9




PROJECT LOCATION:

6FIGURE NO.:



Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)


WA

TER

LE

VE

L


9070503010


9070503010


20015010050



0.0

0.8

4.7

138.3

137.8

133.9

END OF BOREHOLE

Refusal to augering on probable boulder Installed 50 mm Ø monitoring well to 3.7 m. (3.1 m screen) Sand backfill from 0.3 m to 3.7 m. Bentonite seal from 0.2 m to 0.3 m. Provided with monument protective casing.

25 cm TOPSOIL

EARTH FILL brown silty clay, some sand trace of organics

Compact to very dense

SANDY SILT TILL


browngrey

1

20

27

63

105

90/15

70/15

DO

DO

DO

DO

DO

DO

DO

1A

1B

2A

2B

3

4

5

6

7

8

7

6

5

4

3

2

1

017

15

10

10

7

10

W.L

. @ E

l. 13

7.8

m o

n co

mpl

etio

n

W.L

. @ E

l. 13

8.4

m o

n Fe

brua

ry 1

0, 2

017

138.6




PROJECT LOCATION:

7FIGURE NO.:



Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)


WA

TER

LE

VE

L


9070503010


9070503010


20015010050



0.0

0.3

0.7

2.9

6.3

138.2

137.8

135.6

132.2

END OF BOREHOLE

33 cm TOPSOIL

EARTH FILL dark brown to brown sand and gravel, some silt, trace organicsBrown, compact to dense

SAND

fine grained, a trace to some silt

Grey, very dense

SANDY SILT TILL


boulder

4

28

31

24

30/0

53/15

50/15

DO

DO

DO

DO

DO

DO

DO

1A

1B

2

3

4

5

6

7

8

7

6

5

4

3

2

1

0 2414

15

20

16

10

7

5W

.L. @

El.

137.

6 m

on

com

plet

ion

Cav

e-in

@ E

l. 13

7.3

m o

n co

mpl

etio

n

138.5




PROJECT LOCATION:

8FIGURE NO.:



Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)


WA

TER

LE

VE

L


9070503010


9070503010


20015010050



0.0

0.3

0.8

1.8

6.6

137.8

137.3

136.3

131.5 END OF BOREHOLE


28 cm TOPSOIL

EARTH FILL dark brown to brown silty sand, some gravel, trace of organicsBrown, compact

SAND fine to medium grained some silt, a trace of gravel occ. cobbles

Grey, compact

SANDY SILT TILL


tr. gravel

browngrey

5

21

29

13

24

19

18

DO

DO

DO

DO

DO

DO

DO

1A

1B

2

3A3B3C

4

5

6

7

8

7

6

5

4

3

2

1

014

20

21810

12

9

11

10

W.L

. @ E

l. 13

6.9

m o

n co

mpl

etio

nC

ave-

in @

El.

136.

7 m

on

com

plet

ion

W.L

. @ E

l. 13

7.2

m o

n Fe

brua

ry 1

0, 2

017

138.1




PROJECT LOCATION:

9FIGURE NO.:



Ground Surface

El.(m)

Depth(m)

SOILDESCRIPTION

SAMPLES

Num

ber

Type

N-V

alue

Dep

th S

cale

(m)


WA

TER

LE

VE

L


9070503010


9070503010


20015010050



Reference No: 1701-S023

U.S. BUREAU OF SOILS CLASSIFICATION

COARSE

UNIFIED SOIL CLASSIFICATION

COARSE

Project: Proposed Residential Development BH./Sa. 2/6 3/3 5/5

Location: 2024 and 2026 Altona Road and 200 Finch Avenue Liquid Limit (%) = - - -

City of Pickering Plastic Limit (%) = - - -

Borehole No: 2 3 5 Plasticity Index (%) = - - -

Sample No: 6 3 5 Moisture Content (%) = 6 11 10

Depth (m): 4.6 1.7 3.4 Estimated Permeability Elevation (m): 134.8 137.7 135.6 (cm./sec.) = 10-6 10-6 10-6

Classification of Sample [& Group Symbol]: SANDY SILT TILL, some clay, a trace of gravel

GRAIN SIZE DISTRIBUTION

SAND

V. FINE

GRAVELSILT

COARSE FINEFINE

SILT & CLAY

Figure: 10

COARSE

MEDIUM

FINE

CLAY

SAND

MEDIUMFINE

GRAVEL

3" 2-1/2" 2" 1-1/2" 1" 3/4" 1/2" 3/8" 4 8 10 16 20 30 40 50 60 100 140 200 270 325

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Perc

ent P

assi

ng

Grain Size in millimeters

BH.2/Sa.6

BH.5/Sa.

BH.3/Sa.3

Soil Engineers Ltd. Reference No: 1701-S023

U.S. BUREAU OF SOILS CLASSIFICATION

COARSE

UNIFIED SOIL CLASSIFICATION

COARSE

Project: Proposed Residential Development

Location: 2024 and 2026 Altona Road and 200 Finch Avenue Liquid Limit (%) = -

City of Pickering Plastic Limit (%) = -

Borehole No: 8 Plasticity Index (%) = -

Sample No: 3 Moisture Content (%) = 20

Depth (m): 1.7 Estimated Permeability

Elevation (m): 136.8 (cm./sec.) = 10-3

Classification of Sample [& Group Symbol]: FINE SAND, traces of silt and medium sand

FINE

GRAVELSILT & CLAY

MEDIUM

FINE

CLAY

SAND

MEDIUM

Figure: 11GRAIN SIZE DISTRIBUTION

SAND

V. FINE

GRAVELSILT

COARSE FINEFINE

COARSE

3" 2-1/2" 2" 1-1/2" 1" 3/4" 1/2" 3/8" 4 8 10 16 20 30 40 50 60 100 140 200 270 325

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100Perc

ent P

assi

ng

Grain Size in millimeters

BH1

BH3

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90 WEST BEAVER CREEK, SUITE #100, RICHMOND HILL, ONTARIO L4B 1E7 · TEL: (416) 754-8515 · FAX: (905) 881-8335

Soil Engineers Ltd.CONSULTING ENGINEERS

GEOTECHNICAL | ENVIRONMENTAL | HYDROGEOLOGICAL | BUILDING SCIENCE

SITE:

DESIGNED BY: CHECKED BY: DWG NO.:

SCALE: REF. NO.: DATE:

REV

1

Adrian Lo

2024 and 2026 Altona Road and 200 Finch Avenue

1

1 1701-S023 November 2017

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