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Appendix F Geotechnical and Hydrogeological Investigations Report

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Downsview PDR Appendix F_Geotechnical Report - Copy2.pdfCity of Toronto
Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class Environmental Assessment Study City of Toronto, Ontario
Prepared by: AECOM 105 Commerce Valley Drive West, Floor 7 905 886 7022 tel Markham, ON, Canada L3T 7W3 905 886 9494 fax www.aecom.com
November, 2017 Project Number: 60491185
City of Toronto Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class
Environmental Assessment Study City of Toronto, Ontario
60491185_Draft Premilinary Geotechnical Invesetigation Report_20171108.Docx
Distribution List
Revision History
00 Nov. 11, 2017 S. Shah Draft Report
City of Toronto Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class
Environmental Assessment Study City of Toronto, Ontario
AECOM: 2015-04-13 © 2009-2015 AECOM Canada Ltd. All Rights Reserved. 60491185_Draft Premilinary Geotechnical Invesetigation Report_20171108.Docx
Statement of Qualifications and Limitations
The attached Report (the “Report”) has been prepared by AECOM Canada Ltd. (“AECOM”) for the benefit of the Client (“Client”) in accordance with the agreement between AECOM and Client, including the scope of work detailed therein (the “Agreement”). The information, data, recommendations and conclusions contained in the Report (collectively, the “Information”):
is subject to the scope, schedule, and other constraints and limitations in the Agreement and the qualifications contained in the Report (the “Limitations”);
represents AECOM’s professional judgement in light of the Limitations and industry standards for the preparation of similar reports;
may be based on information provided to AECOM which has not been independently verified; has not been updated since the date of issuance of the Report and its accuracy is limited to the time period and
circumstances in which it was collected, processed, made or issued; must be read as a whole and sections thereof should not be read out of such context; was prepared for the specific purposes described in the Report and the Agreement; and in the case of subsurface, environmental or geotechnical conditions, may be based on limited testing and on the
assumption that such conditions are uniform and not variable either geographically or over time. AECOM shall be entitled to rely upon the accuracy and completeness of information that was provided to it and has no obligation to update such information. AECOM accepts no responsibility for any events or circumstances that may have occurred since the date on which the Report was prepared and, in the case of subsurface, environmental or geotechnical conditions, is not responsible for any variability in such conditions, geographically or over time. AECOM agrees that the Report represents its professional judgement as described above and that the Information has been prepared for the specific purpose and use described in the Report and the Agreement, but AECOM makes no other representations, or any guarantees or warranties whatsoever, whether express or implied, with respect to the Report, the Information or any part thereof. Without in any way limiting the generality of the foregoing, any estimates or opinions regarding probable construction costs or construction schedule provided by AECOM represent AECOM’s professional judgement in light of its experience and the knowledge and information available to it at the time of preparation. Since AECOM has no control over market or economic conditions, prices for construction labour, equipment or materials or bidding procedures, AECOM, its directors, officers and employees are not able to, nor do they, make any representations, warranties or guarantees whatsoever, whether express or implied, with respect to such estimates or opinions, or their variance from actual construction costs or schedules, and accept no responsibility for any loss or damage arising therefrom or in any way related thereto. Persons relying on such estimates or opinions do so at their own risk. Except (1) as agreed to in writing by AECOM and Client; (2) as required by-law; or (3) to the extent used by governmental reviewing agencies for the purpose of obtaining permits or approvals, the Report and the Information may be used and relied upon only by Client. AECOM accepts no responsibility, and denies any liability whatsoever, to parties other than Client who may obtain access to the Report or the Information for any injury, loss or damage suffered by such parties arising from their use of, reliance upon, or decisions or actions based on the Report or any of the Information (“improper use of the Report”), except to the extent those parties have obtained the prior written consent of AECOM to use and rely upon the Report and the Information. Any injury, loss or damages arising from improper use of the Report shall be borne by the party making such use. This Statement of Qualifications and Limitations is attached to and forms part of the Report and any use of the Report is subject to the terms hereof.
AECOM 105 Commerce Valley Drive West, Floor 7 905 886 7022 tel Markham, ON, Canada L3T 7W3 905 886 9494 fax www.aecom.com
60491185_Draft Premilinary Geotechnical Invesetigation Report_20171108.Docx
November 11, 2017 Ms. Dina Kuvandykova, P. Eng. Trunk Sewers and Transmission Mains Engineering & Construction Services City of Toronto Metro Hall, 20th Floor 55 John Street Toronto, Ontario M5V 3C6 Dear Ms. Kuvandykova: Project No: 60491185 Regarding: Preliminary Geotechnical Investigation for Downsview Area Long Term Water
Servicing - Municipal Class Environmental Assessment Study City of Toronto, Ontario
AECOM Canada Ltd. (AECOM) is pleased to submit this draft report to City of Toronto (the City) providing the findings and recommendations of our preliminary geotechnical investigation for the above captioned site, located within City of Toronto, Ontario. Should you have any questions, please do not hesitate to contact the undersigned. Sincerely, AECOM Canada Ltd. Douglas McLachlin, M.Sc., P.Eng. Geotechnical Practice Area Lead DM:gz Encl. cc:
City of Toronto Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class
Environmental Assessment Study City of Toronto, Ontario
60491185_Draft Premilinary Geotechnical Invesetigation Report_20171108.Docx
Quality Information
Geotechnical Engineer
Report Reviewed By:
Geotechnical Practice Area Lead
City of Toronto Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class
Environmental Assessment Study City of Toronto, Ontario
60491185_Draft Premilinary Geotechnical Invesetigation Report_20171108.Docx 1
Table of Contents
2. Investigation Procedures ................................................................................................ 2
3. Subsurface Conditions .................................................................................................... 5
3.1 Regional Geology .............................................................................................................. 5 3.2 Subsurface Conditions ....................................................................................................... 5
3.2.1 Topsoil ................................................................................................................... 5 3.2.2 Pavement Structure ................................................................................................ 5 3.2.3 Fill .......................................................................................................................... 5 3.2.4 Clayey Silt .............................................................................................................. 6 3.2.5 Glacial Till .............................................................................................................. 6
Clayey Silt Till ........................................................................................................................ 6 Sandy Silt / Silty Sand Till ...................................................................................................... 7
3.2.6 Silty Clay ................................................................................................................ 7 3.2.7 Sand....................................................................................................................... 8 3.2.8 Groundwater Conditions ......................................................................................... 8
4. Discussions and Recommendations for Design and Construction ............................ 9
4.1 General Discussions .......................................................................................................... 9 4.2 Recommendations for Design and Construction ................................................................ 9
4.2.1 Open Cut Sections ............................................................................................... 10 4.2.2 Pipe Bedding and Cover....................................................................................... 12 4.2.3 Trench Backfilling ................................................................................................. 12 4.2.4 Trenchless Method ............................................................................................... 12 4.2.5 Groundwater Control and Dewatering .................................................................. 14 4.2.6 Soil Corrosivity ..................................................................................................... 15 4.2.7 Environmental Soil Test Results ........................................................................... 16
5. Closure............................................................................................................................ 16
City of Toronto Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class
Environmental Assessment Study City of Toronto, Ontario
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List of Tables Table 1: Summary of Borehole Locations, Depths and Elevations ......................................................................... 3 Table 2: Summary of Number of Samples and Analytical Parameters ................................................................... 4 Table 3: Groundwater Level Measurements ........................................................................................................... 8 Table 4: Diameter of Proposed Watermain and Thickness of All-Around Encased Concrete .............................. 10 Table 5: Geotechnical Resistances ....................................................................................................................... 11 Table 6: Geotechnical Design Parameters............................................................................................................ 11 Table 7: Geotechnical Resistances ....................................................................................................................... 13 Appendices Appendix A. Borehole Location Plans and Borehole Profiles Appendix B. Record of Borehole Sheets Appendix C. Geotechnical Laboratory Test Results Appendix D. Corrosivity and Environmental Soil Testing Results Appendix E. Lateral Earth Pressure Distribution Diagram
City of Toronto Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class
Environmental Assessment Study City of Toronto, Ontario
60491185_Draft Premilinary Geotechnical Invesetigation Report_20171108.Docx 1
1. Introduction
AECOM Canada Ltd. (AECOM) was retained by City of Toronto (the City) to carry out a preliminary geotechnical investigation for the proposed transmission watermain construction connecting the Keele Pumping station, located near The Chimneystack Road and Keele Street to the Downsview Water Distribution System in City of Toronto, Ontario.
Based on the AECOM’s initial study, the alignment of the transmission watermain will be running south from Keele Pumping Station along Keele Street, Tangiers Road, Toro Road, Ceramic Road, St. Regis Crescent North, St. Regis Crescent South, Tuscan Gate, and Sheppard Avenue West to Downsview Water Distribution System. The preliminary investigation field work plan was developed to support the preliminary design of original alignment.
However, during design progress, an alignment change at the southern end was proposed and the proposed watermain will be running along St. Regis Crescent North, then south on Bakersfield Street, as confirmed in August, 2017. Given the timing of the alignment change, additional investigations were not included in this preliminary geotechnical investigation program and report. The additional investigations should be carried out during the detailed design stage.
At the time of developing the investigation program and preparing the report, the detailed design of the proposed transmission watermain, including the watermain size, the invert levels and the detailed watermain alignment (i.e. boulevard, road lane, median, etc.) had not been finalized. Based on the available information, it is understood that the construction methods are proposed to be a combination of open cut and trenchless technologies. The open cut method for the watermain construction is proposed from the Keele Pumping Station to approximately 150 m east of the intersection of Keele Street and Murray Ross Parkway and from the intersection of Tangiers Road and Toro Road to the Downsview Water Distribution System. The trenchless method is proposed to be carried out along Tangiers Road between the entry and exit shafts. The entry and exit shafts are proposed to be at the north and south ends of Tangiers Road, however, the depths of the shafts and watermain had not been finalized at the time of preparing this report.
The purpose of the geotechnical investigation was to obtain information about the subsurface conditions at the site by means of advancing boreholes, and to assess the engineering characteristics of the subsurface soils by means of field and laboratory tests at the preliminary design stage. This report provides factual information including subsurface conditions and laboratory test results, and discussions and recommendations for preliminary design purposes, and during the construction stage.
A total of ten (10) boreholes, BH 17-1 to BH 17-10 were advanced along the original proposed watermain alignment. However, due to the alignment change at the southern end, two (2) boreholes, BH 17-9 and BH 17-10, were no longer applicable to support the new alignment. As a result, this report will provide the subsurface information and recommendations for the alignment from Keele Pumping Station to the intersection of Ceramic Road and St. Regis Crescent North based on boreholes BH 17-1 to BH 17-8.
City of Toronto Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class
Environmental Assessment Study City of Toronto, Ontario
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1.1 Scope of Work
The scope of work includes the following services to be provided by AECOM to the City of Toronto: Preparing a geotechnical investigation plan, layout of boreholes, and clearing of underground utilities; Engaging a drilling sub-contractor, advancing boreholes to collect soil samples, and installing monitoring
wells; Laboratory testing of selected soil samples; Completing a detailed visual analysis of soil samples, preparing borehole logs, and preparing borehole
location plan; and, Preparing a geotechnical report presenting the findings of the geotechnical investigation, laboratory test
results and geotechnical recommendations including construction considerations.
2. Investigation Procedures
The borehole locations are provided in the Site Plan and Borehole Location Plans, Figures 1.0 to 10.0 in Appendix A.
The borehole locations were established in the field by AECOM engineering staff in relation to existing features. The underground utilities at the borehole locations were cleared by the designated public locate companies through Ontario One Call system and they were field verified by a private locator, Utility Marx Inc. in Ontario.
The fieldwork was carried out on July 26 and 31, and August 2 and 8, 2017. It consisted of drilling and sampling ten (10) boreholes (BHs 17-1 to BH 17-10) that were advanced at the proposed locations using a truck-mounted CME 75 drilling rig to a depth ranging from 6.2 to 10.5 m below ground surface (bgs), and the monitoring wells were installed in all ten (10) drilled boreholes.
The boreholes were drilled using continuous flight hollow stem augers. Both drilling and traffic control services were provided by Geotech Support Services Inc. based in Markham, Ontario under the full-time supervision of AECOM engineering staff.
Standard Penetration Tests (SPTs) were carried out at selected intervals to assess the soil strength and to obtain samples for testing purposes. SPTs were carried out in general accordance with ASTM D1586. The test consists of freely dropping a 63.5 kg hammer over a vertical distance of 0.76 m to drive a 51 mm outside diameter (O.D.) split- barrel (split-spoon) sampler into the ground. The number of blows of the hammer required to drive the sampler into the relatively undisturbed ground over a vertical distance of 0.30 m is recorded as the Standard Penetration Resistance or the N-value of the soil, which is indicative of the compactness condition of granular (or cohesionless) soils (gravels, sands and silts) or the consistency of cohesive soils (clays and clayey soils).
Monitoring wells were installed in the open boreholes upon completion of augering in accordance with the requirements prescribed in R.R.O. 1990, Ontario Regulation 903 “Wells” (as amended) (Ontario Water Resources Act, 1990), and they were constructed using 51 mm diameter PVC Schedule 40 well screens and solid riser pipes. Commercially manufactured well screen pipe with a standard slot size of 10 were used for these installations. Monitoring wells were completed using a well point cap that was threated to the screen bottom. A J-plug was used to cover the top of the well riser pipe. A filter pack consisting of clean, inert rounded to sub-rounded 1 to 3 mm
City of Toronto Preliminary Geotechnical Investigation for Downsview Area Long Term Water Servicing - Municipal Class
Environmental Assessment Study City of Toronto, Ontario
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diameter silica sand was installed around each well screen, and the bentonite in pellet (free of chemical additives) was used as an non-permeable seal within the borehole annulus above the silica sand. The wells were completed using a flush-mounted steel cap and a cement mixture. The monitoring wells were tagged in accordance with O. Reg. 903 (as amended) and a water well record was submitted by the drilling contractor to the Ministry of Environment and Climate Change (MOECC).
The groundwater levels were observed in the boreholes upon the completion of drilling, where encountered, and they will be measured and monitored in the monitoring wells.
Table 1 below presents a summary of the borehole locations and the borehole termination depths in meters below the ground surface (mbgs) and elevations in meters above sea level (mASL).
Table 1: Summary of Borehole Locations, Depths and Elevations
Borehole Number1 Borehole Location2 Ground Surface Elevation (mASL)
Borehole Depth (mbgs)
Borehole Bottom Elevation (mASL)
BH 17-1 Keele St.
204.6 6.2 198.4 BH 17-2 200.0 6.7 193.3 BH 17-3 198.2 6.7 191.5 BH 17-4
Tangiers Rd. 197.7 9.6 188.1
BH 17-5 197.3 9.8 187.5 BH 17-6 196.4 10.5 185.9 BH 17-7 Ceramic Rd. 195.2 6.7 188.5 BH 17-8 194.4 6.7 187.7 BH 17-9 St. Regis Cres. - 6.7 -
BH 17-10 Tuscan Gt. - 6.7 - Notes: 1.BH 17-9 and BH 17-10 are no longer applicable for the revised alignment, and they were not surveyed. 2. Borehole locations are presented in Figures 1.0 to 10.0 in Appendix A.
Soil samples were transported to AECOM’s Geotechnical Laboratory in Etobicoke, Ontario for visual and tactile examination and classification. Selected soil samples were tested, and the laboratory testing program consisted of natural moisture content tests, Grain Size Distribution analyses and Atterberg Limits tests. All the laboratory tests are in accordance with ASTM Standards. Selected soil samples were tested at AGAT Laboratories, Ontario for corrosivity.
Environmental soil sampling program was completed as a part of geotechnical investigation for evaluating the environmental quality of fill material and native subsurface soil for the on-site waste management. The selected soil samples were submitted for chemical laboratory analysis for general chemistry and inorganic parameters (including metals, SAR, EC, pH, etc.), Volatile Organic Compounds (VOCs), Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) / Petroleum Hydrocarbon (PHCs) in fraction F1-F4, Polycylic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs) and Toxic Characteristic Leachate Procedure Testing (TCLP) (including VOC’s, PAHs, Metals and Inorganics, and PCBs).
All the soil samples selected for testing based on the vapour readings, visual (i.e. staining, discoloration) and olfactory observations, and “worst case” soil samples were selected for subsequent laboratory analysis. In addition, sampling depths and different soil strata, as well as the depth of the groundwater were all taken into consideration in selecting soil samples for testing. No visual aesthetic impacts (i.e. oil staining, odours, unusual debris, etc.) were observed in any soil sample collected from fill and native during the sampling events, unless noted in the borehole logs.
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Environmental Assessment Study City of Toronto, Ontario
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For the waste management consideration, one composite soil sample from soil cutting was collected and labelled as TCLP-1 (worst case scenario) and submitted to the laboratory toxicity characteristic leaching procedure (TTCLP- Soil Cutting) for VOCs, Metals and Inorganics, PAHs, PCBs parameters.
All collected soil samples were submitted to the AGAT Laboratories of Mississauga, Ontario. AGAT is a member of the Canadian Association for Laboratory Accreditation Inc. (CALA) and meets the requirements of Section 47 of O.Reg.153/04 certifying that the analytical laboratory be accredited in accordance with the International Standard ISO/IEC 17025 and with standards developed the Standards Council of Canada.
A total of 26 soil samples were collected during the investigation event from BH 17-1 to BH 17-8, and submitted for the laboratory analysis as follows in Table 2.
Table 2: Summary of Number of Samples and Analytical Parameters
Number of Samples
8
BH 17-8 SS 3, BH 17-5-SS 2, BH 17-7-SS 2, BH 17-6 SS 3,
BH 17-3 SS 3, BH 17-4 SS 11 (Bottom), BH 17-1 SS 3, BH 17-2 SS 4
General Chemistry and Inorganic Parameters (including metals, SAR, EC, pH etc.)
7
BH 17-5 SS 9A, BH 17-7 SS 6, BH 17-6 SS 6, BH 17-3 SS 5,
BH 17-4 SS 7, BH 17-1 SS 4, BH 17-2 SS 6
Volatile Organic Compounds (VOCs)
3 BH 17-8 SS 1B, BH 17-4 SS 1 (Bottom),
BH 17-1 SS 3
F1-F4
4 BH 17-5 SS 2, BH 17-6 SS 4, BH 17-4 SS 2
BH 17-2 SS 5 Polycyclic Aromatic Hydrocarbons (PAHs)
3 BH 17-6 SS 5, BH 17-4 SS 5, BH 17-1 SS 5 Polychlorinated Biphenyls (PCBs)
1 TCLP-Soil Cutting
(Including VOC’s, PAHs, Metals and inorganics, PCBs)
Note: Results of selected samples from BH 17-9 and BH 17-10 are not included as these 2 boreholes are on the initial alignment.
The Borehole Location Plan and Borehole Profiles are presented in Appendix A. The Record of Borehole Sheets is included in Appendix B. The results of the laboratory tests are presented on the borehole logs in Appendix B, and the test results including the Grain Size Distribution Analysis and Atterberg limit tests in Appendix C. Corrosivity and environmental soil testing results are presented in Appendix D.
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Environmental Assessment Study City of Toronto, Ontario
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3. Subsurface Conditions
3.1 Regional Geology
The project site is located within the physiographic region known as the Peel Plain (Chapman and Putnam 1984), and most of the plain area consists of glacial till partly modified by the former presence of shallow glacial lakes or post-glacial erosion features. The till in the project site is mapped as Halton Till, which is generally considered as a fine-grained deposit with minor fine-grained lacustrine sediments. The Halton Till is typically stiff to hard in consistency, and weathering near the ground surface can result it in it being degraded to consistencies from soft to firm. Cobbles and boulders are contained in the Halton Till.
The surface topography of the plain is characterized by a gradual and fairly uniform slope toward Lake Ontario.
3.2 Subsurface Conditions
In general, the subsurface conditions at all borehole locations consist of topsoil or pavement structure overlying various fill materials, which is underlain by clayey silt overlying glacial till deposits. Underneath the glacial till deposit, granular layers were encountered in BH 17-4 and BH 17-6, while silty clay layer was encountered in BH 17-5 and BH 17-7. The records of Borehole Logs are presented in Appendix B.
3.2.1 Topsoil
A 130 to 175 mm thick layer of topsoil was encountered at the surface in boreholes BH 17-1 to BH 17-4 and BH 17-6 to BH 17-8.
3.2.2 Pavement Structure
A pavement structure with 130 mm thick asphalt and 0.6 m thick pavement granular fill was encountered at the surface in borehole BH 17-5.
3.2.3 Fill
A 0.3 to 2.1 m thick layer of fill was encountered in all boreholes below topsoil, except BH 17-5. The fill extended to the depths ranging from 0.5 to 2.3 mbgs (Elevation 192.9 to 203.1 m). Various amounts of clay, silt, sand and gravel with inclusions of organics and rootlets were encountered in the fill materials. N-values ranged between 6 and 43 blows per 30 cm penetration.
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Environmental Assessment Study City of Toronto, Ontario
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The natural moisture contents measured within the fill materials ranged from 3 to 24%.
3.2.4 Clayey Silt
A 0.6 to 1.8 m thick brown to grey clayey silt layer was encountered in all boreholes below pavement structure or fill materials at the depth ranging from 0.5 to 1.7 mbgs (Elevation 193.5 to 199.2 m), except BH 17-1 and BH 17-7, and it extended to depths ranging from 1.7 to 2.7 mbgs (Elevation 191.7 to 197.6 m). N-values ranged from 8 to 24 blows per 30 cm penetration, indicating the clayey silt has a firm to very stiff consistency.
The natural moisture contents measured within the fill materials ranged from 12 to 29%.
3.2.5 Glacial Till
Glacial till deposits consisting of clayey silt and sandy silt to silty sand were encountered in all boreholes. It should be noted that based on resistance encountered during auger advancement/grinding, cobbles and boulders are likely present within the glacial till deposit.
Clayey Silt Till
With the exception of BH 17-7, a 2.8 to 5.0 m thick brown to grey clayey silt till deposit was encountered in all boreholes below fill or clayey silt at the depths ranging from 1.5 to 2.7 mbgs (Elevation 191.7 to 203.1 m), and it extended to the depths ranging from 4.5 to 7.0 mbgs (Elevation 190.3 to 198.8 m). BH 17-8 was terminated within clayey silt till. N-values ranged from 9 to 50 blows per 30 cm penetration, indicating the deposit has a stiff to hard consistency.
The grain size distribution results of three (3) selected clayey silt till samples are presented in Figure GSD-1 in Appendix C. The grain size distribution is as follows:
Grave Sized Particles: 1 to 2 %
Sand Sized Particles: 30 to 37 %
Silt Sized Particles: 35 %
Clay Sized Particles: 26 to 34 %
The corresponding Atterberg limits results of the selected samples are given in Figure AL-1, Appendix C and are summarized below:
Liquid Limit: 17 to 22 %
Plastic Limit: 12 to 15 %
Plasticity Index: 5 to 7 %
The natural moisture contents measured within the clayey silt till samples were 7 and 18%.
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Sandy Silt / Silty Sand Till
A 0.3 to 3.3 m thick light brown to grey sandy silt to silty sand till deposit was encountered below the fill or clayey silt till at depths ranging from 2.3 to 9.3 mbgs (Elevation 188.4 to 198.8 m) in all boreholes except BH 17-8, and it extended to 5.6 to 9.6 mbgs (Elevation 187.9 to 189.6 m). BH 17-1 and BH 17-3 were terminated within this till deposits. A 0.5 m thick sand layer was also encountered at depth 8.8 mbgs (Elevation 188.9 m) within sandy silt to silty sand till deposit in BH 17-4. The SPT N-value was 26 to in excess of 100 blows per 30 cm penetration, indicating the deposit has compact to very dense relative density.
The grain size distribution results of one (1) selected samples are presented in Figure GSD-2 in Appendix C. The grain size distribution is as follows:
Grave Sized Particles: 2 %
Sand Sized Particles: 43 %
Silt Sized Particles: 36 %
Clay Sized Particles: 19 %
The natural moisture contents measured within the silty sand to sandy silt till samples were 6% and 15%.
3.2.6 Silty Clay
In two of the boreholes (BH 17-5 and BH 17-7), a 0.4 and 1.1 m thick grey silty clay was encountered below the sandy silt till deposit at the depths ranging from 5.6 to 9.4 mbgs (Elevation 187.9 to 189.6 m). Both boreholes were terminated within this deposit at depths ranging from 6.7 to 9.8 mbgs (Elevation 187.5 to 188.5 m). N-values were 31 and 48 per 30 cm penetration, indicating the deposit has a hard consistency.
The grain size distribution results of one (1) selected silty clay sample are presented in Figure GSD-3 in Appendix C. The grain size distribution is as follows:
Grave Sized Particles: 0 %
Sand Sized Particles: 7 %
Silt Sized Particles: 37 %
Clay Sized Particles: 56 %
The corresponding Atterberg limits results of the selected sample are given in Figure AL-2, Appendix C and are summarized below:
Liquid Limit: 33 %
Plastic Limit: 21 %
Plasticity Index: 12 %
The natural moisture contents measured within the silty clay samples were 15%.
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Environmental Assessment Study City of Toronto, Ontario
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3.2.7 Sand
A 0.2 and 0.5 m thick brown to grey sand layer was encountered within the glacial till deposit at 8.8 and 4.5 mbgs (Elevation 188.9 to 191.9 m), and it extended to 9.3 and 4.7 mbgs (Elevation 188.4 and 191.7 m) in boreholes BH 17-4 and BH 17-6, respectively.
A 2.9 m thick lower sand layer was encountered below the sandy silt to silty sand till in BH 17-6 at the depth of 7.6 mbgs (Elevation 188.8 m), and it extended to the borehole termination depth of 10.5 mbgs (Elevation 185.9 m).
In general, N-values were 21 to 97 blows per 30 cm penetration, indicating the sand has a compact to very dense relative density. A low N-value of 8 blows per 30 cm penetration was encountered locally in BH 17-6, and this was likely due to possible hydraulic disturbance.
The grain size distribution results of one (1) selected sand sample are presented in Figure GSD-4 in Appendix C. The grain size distribution is as follows:
Grave Sized Particles: 5 %
Sand Sized Particles: 78 %
Silt Sized Particles: 9 %
Clay Sized Particles: 8 %
The natural moisture contents measured within the sand samples were 8 and 17%.
3.2.8 Groundwater Conditions
Groundwater was observed upon the completion of the drilling in the boreholes BH 17-2 to BH 17-6. Monitoring wells were installed with 51 mm PVC risers and screens in all the boreholes. The groundwater levels were measured upon the completion of drilling and in the monitoring wells (before well development), and these are presented in Table 3 below.
Table 3: Groundwater Level Measurements
Borehole Number Borehole Location1
(not stabilized)
(before well development)
Depth (mbgs) Elevation (mASL) Depth (mbgs) Elevation (mASL) BH 17-1 Keele St. - - 4.2 200.4 BH 17-2 4.5 195.5 2.9 197.1 BH 17-3 5.6 192.6 2.1 196.1 BH 17-4 Tangiers Rd. 6.1 191.6 2.2 195.5 BH 17-5 7.7 189.6 6.3 191.0 BH 17-6 Toro Rd. 4.6 191.8 2.8 193.6 BH 17-7 Ceramic Rd. - - 2.0 193.2 BH 17-8 - - 2.1 192.3
Note: 1.The borehole locations are presented in Figures 1.0 to 10.0 in Appendix A.
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It should be noted that the groundwater levels from the monitoring wells were measured before well development. The static groundwater levels are reported in a separate hydrogeology addendum. It should also be noted that the groundwater levels are subject to seasonal fluctuations.
4. Discussions and Recommendations for Design and Construction
4.1 General Discussions
The transmission watermain is proposed to be constructed to connect the Keele Pumping Station and Downsview Water Distribution System in City of Toronto, Ontario. The original proposed alignment runs south along Keele Street, Tangiers Road, Toro Road, Ceramic Road, St. Regis Crescent North, St. Regis Crescent South, Tuscan Gate, and Sheppard Avenue West. However, due to an alignment change at the south end connecting to the Downsview Water Distribution System in August 2017, this report provides the findings of the subsurface conditions and general recommendations for construction for the alignment from Keele Pumping Station to the intersection of St. Regis Crescent North and Ceramic Road only. It is noted that an additional investigation for the revised southern alignment along St. Regis Crescent North and Bakersfield Street should be carried out during the detailed design stage.
It is understood that the open cut construction method will be implemented for the stretch between Keele Pumping Station to approximately 150 m east of the intersection of Keele Street and Tangiers Road and from the intersection of Tangiers Road and Toro Road to Downsview Water Distribution System. It is also understood that the trenchless methods together with shafts excavation (at both ends) will be adopted for the watermain construction along Tangiers Road. However, the details of the proposed watermain, including the watermain size, invert depth, shaft depths, and the detailed watermain alignment (i.e. boulevard, road lane, median etc.) had not been finalized at the time of preparing this report. Therefore, it is assumed that the invert depth of the watermain along the open cut section may be between 2.0 and 5.0 m below the existing surface grade, and the invert depth along the trenchless section may be about 7.0 m to 10.0 m below the existing surface grade.
The subsurface conditions at the borehole locations generally consists of topsoil or pavement structure overlying various fill materials, and this is further underlain by clayey silt overlying glacial till deposits. Compact to very dense sand layers were encountered in boreholes BH 17-4 and BH 17-6, and a hard silty clay was encountered in BH 17- 5 and BH 17-7.
Groundwater was observed at the depths ranging from 4.5 to 7.7 mbgs upon completion of drilling in five (5) boreholes. Based on a single set of monitoring well readings (before well development) in all the boreholes, the groundwater depth ranged from 2.0 to 6.3 mbgs.
4.2 Recommendations for Design and Construction
The following recommendations are for preliminary design purposes only, and further detailed investigation may be required during the detailed design stages, when more design details of the proposed watermain become available.
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4.2.1 Open Cut Sections
The open cut method was proposed for the watermain construction from the Keele Pumping Station to north shaft of trenchless (approximately 150 m east of the intersection of Keele Street and Murray Ross Parkway) and from the south shaft of the trenchless section (the intersection of Tangiers Road and Toro Road) to the Downsview Water Distribution System.
At the time of preparation of this report, no information was available on the invert level/depth of the proposed watermain and it was therefore assumed that the invert level of watermain, in the open cut section will be at approximately 2.0 to 5.0 m below existing grade. Based on this assumption, it is anticipated that the proposed watermain would be supported on native clayey silt or clayey silt till or sand or sandy silt till. It is noted that at Borehole (BH 17-7), fill was encountered to a depth of 2.3 m and it is recommended that the fill be removed and replaced with engineered fill in the vicinity of BH 17-7.
From the available information, it is understood that the proposed transmission watermain pipe material will be steel, and it will be encased with concrete as per City Standards. The steel pipe material and welding joints related requirements shall conform to City Standard TS-1802 and OPSS 1802. The encasement material should be minimum 20 MPa Reinforced Concrete as per City Standard Drawing T-1110.01-10. The width of the all-around encased concrete should be between 150 mm and 300 mm, depending on diameter of proposed watermain, as shown below (Table 4):
Table 4: Diameter of Proposed Watermain and Thickness of All-Around Encased Concrete
Diameter of Proposed Watermain (Welded Steel Pipe) (mm)
Thickness of All-Around Encased Concrete (mm)
750 – 1500 150
1550 – 1900 200
>1900 300
The width of the trench should be a minimum of 800 mm plus the width of encasement block (for example: if 1600 mm diameter pipe will be proposed, the concrete encasement block will be 2.0 m wide and the trench width should not be less than 2.8 m), as required by the City of Toronto Standard Drawing.
Temporary excavations within the open cut sections should be carried out in accordance with Occupational Health and Safety Act (OHSA) regulations. The excavation zones along the proposed alignment based on the borehole information will be in fill materials above groundwater table, which can be classified as Type 3 soils and in clayey silt and clayey silt till above groundwater table, which can be classified as Type 2 soils. The soils below groundwater table can be classified as Type 4. The temporary excavation slopes should be battered not steeper than 1H:1V for Type 1, 2 and 3 soils. For Type 4 soils, the excavation slopes should be battered not steeper than 3H:1V, unless a shoring/support of excavation is included in the design. OPSD 802 series should be referenced for excavations in each type of soil.
Temporary excavation support (i.e. shoring) will be required in areas where sufficient space is not available to use open cut methods and/or in other areas where existing features and facilities (i.e. existing underground utilities) require protection. The apparent lateral earth pressure distribution diagram is represented in Appendix E. The temporary excavation support may consist of multiple trench boxes, sheet piling, and timber shoring system or
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equivalent. The design and construction of the temporary excavation support system should follow OPSS.MUNI 539 (Construction Specification for Temporary Protection Systems).
The surcharge loading such as vehicular traffic movement, construction equipment or material should not be allowed within safe horizontal distance of 1H:2V line for excavation up to 3.0 m depth or horizontal distance of 1H:1V line for excavation exceeding 3.0 m depth. The line measurements should be projected from the dredge line at the face of the protection system to the roadway surface as per OPSS MUNI 539. In the planning of trench shoring and excavation, the presence of adjacent existing utilities and structures should be considered including their stability, and they must be maintained without detrimental settlements/movements.
For preliminary design purposes, the geotechnical resistance at Ultimate Limit State (ULS) and geotechnical reaction at Serviceability Limit State (SLS) of the undisturbed native soil at the anticipated invert depth of the watermain based on the borehole information and the geotechnical design parameters, including coefficient of friction and friction angles, are provided in Table 5 and Table 6 below, respectively. Further investigation and engineering assessment will be required during the final design.
Table 5: Geotechnical Resistances
(kPa)
Geotechnical Reaction at SLS** (kPa)
2.0 to 5.0 mbgs Native stiff to hard clayey silt till / dense to very dense sandy silt till
250 175
Notes: * The invert depth of the watermain along the open cut section was assumed to be between 2.0 to 5.0 mbgs. Near Borehole BH17-7, the fill material up to 2.3 m depth should be replaced if the invert level is above that depth. **Bearing capacities are estimated based on SPT N-values.
Table 6: Geotechnical Design Parameters
Materials Unit Weight (kN/m3)
Undrained Shear Strength (kPa)
Granular 'A' and 'B' Type II
22 - 35 0.27 3.70 0.43
Stiff Clayey Silt 19 50 26** 0.39 2.56 0.56
Stiff to very Stiff Clayey Silt Till
21 100 30** 0.33 3.69 0.50 – 0.80
Sandy Silt Till 21 - 34 0.28 3.54 0.44 – 0.80
Sand 19 - 30 - 33 0.33 3.69 0.45 - 0.50
Notes: * Coefficients of lateral earth pressure were calculated based on Canadian Foundation Engineering Manual (CFEM), 4th Edition. ** Effective friction angles for cohesive soils are for long term (i.e. drained) conditions.
The recommendations for groundwater control and dewatering are provided in Section 4.2.5 of this report.
Concrete for thrust blocks shall be placed against undisturbed soil. The bearing resistance at SLS of 100 kPa and factored bearing resistance at ULS of 150 kPa can be used for stiff to very stiff clayey silt. A bearing resistance at SLS of about 150 kPa and a factored bearing resistance at ULS 225 kPa may be used for clayey silt till.
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4.2.2 Pipe Bedding and Cover
The bedding of the watermain should be compatible with the type and the class of the pipe, the surrounding subsoil and anticipated loading conditions and should be designed in accordance with the Standard Specifications of City of Toronto, TS-401 (amendment to OPSS.MUNI 401), and the bedding materials should be Granular A or Granular A RCM (Recycled Concrete Material) conforming to TS-1010 (amendment to POSS.MUNI 1010). Cover materials may be considered as Granular A, or Granular B Type II as per OPSS.MUNI 401. All bedding and cover materials shall be placed in maximum 200 mm thick uniform loose layers, and each layer shall be compacted to at least 98% of the materials’ Standard Proctor Maximum Dry Density (SPMDD) according to TS-501. Bedding and cover on each side of the pipe shall be completed simultaneously, and at no time are the levels on each side to differ by more than 300 mm.
4.2.3 Trench Backfilling
The selection and placement of the backfill material should be in accordance with Standard Specifications of City of Toronto, TS-401 (amendment to OPSS.MUNI 401). The backfill material should be Granular A or Granular A RCM as per TS 1010 or unshrinkable fill. The trench backfill shall be placed in maximum 300 mm thick lifts for the full width of the trench and compacted to 95% of SPMDD in accordance to TS-501. It is recommended that the upper 1.0 m zone of the trench backfill under the proposed road pavement should be compacted to at least 98% of the SPMDD. The operations of backfilling and compaction should be monitored by qualified geotechnical personnel.
It is recommended that the trench backfilling should be carried out as soon as possible following excavation and service installation.
The trench support system such as trench boxes or equivalent should be removed gradually as the trench is being backfilled. The supporting system should not be removed until the excavation is backfilled, and the area behind the supporting system should be carefully backfilled to ensure that all voids are completely filled.
4.2.4 Trenchless Method
Trenchless construction methods were proposed for the construction along Tangiers Road, from approximately 150 m east of Keel Street to the intersection of Tangiers Road and Toro Road.
This section of the report is based on the information available at the time the report was prepared and only addresses general aspects of typical trenchless methods for the watermain installation. Further geotechnical investigation and engineering assessment should be carried out when the preferred method and more design data including vertical alignment are available. At this time, the invert level along the trenchless section is assumed between about 7.0 m to 10.0 m below the existing surface grade. Based on this assumption, it is anticipated that the proposed trenchless system will be in native dense to very dense sandy silt to silty sand till and hard silty clay. At the southern limit of the proposed trenchless system, a layer of sand having a compact relative density was encountered at about 7.6 m depth from existing grade (Elevation 188.8 m). Therefore it is recommended to investigate the lateral extent of this layer during detailed design stage and also should be considered in final design of invert levels within the lateral extent of this deposit.
Based on subsurface and groundwater conditions encountered in the boreholes, microtunnelling is considered more feasible and safer. Horizontal Directional Drilling (HDD) may also be considered based on final alignment and invert levels. However, the contractor will be fully responsible for the selection of the trenchless technology which
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best fits the contract requirements based on his experience, and the availability of trained staff and equipment. All the trenchless work should be carried out by an experienced specialist contractor employing only qualified workers skilled in their trade under the direction of an experienced foreman. The contractor’s work plan should include a provision for grouting should the need arise. It is recommended that the geotechnical aspects of the contractor’s work plan for the trenchless method be reviewed by a qualified and experienced geotechnical engineer prior to construction.
Typically, a minimum earth cover thickness of about three times the tunnel diameter should be considered for most tunnelling methods.
For preliminary design purposes, the geotechnical resistance at Ultimate Limit State (ULS) and geotechnical reaction at Serviceability Limit State (SLS) of the undisturbed native soil at the anticipated invert depth of the watermain are provided in Table 7. Further investigation and engineering assessment will be required for the final design.
Table 7: Geotechnical Resistances
(kPa)
7.0 to 10.0 mbgs Native compact to very dense
sand/sandy silt to silty sand till / hard silty clay
250 175
Notes: * The invert level of watermain along trenchless section was assumed to be between 7.0 and 10.0 mbgs. **Bearing capacities are estimated based on SPT N-values.
Microtunnelling is an improvement on the use of pipe jacking and it uses a laser guided Micro-Tunnelling Boring Machine (MTBM). It is a remotely controlled, guided pipe-jacking process that provided continuous support to the excavation face. The guidance system usually consists of a GPS mount in the drive shaft, communicating a reference line to a target mounted inside the tunnelling machine. This technique provides an ability to control the excavation face stability by applying mechanical or fluid pressure to counterbalance the earth and hydrostatic pressures. Therefore, no dewatering may be required between the shafts as it is a closed system operation for the entire tunnel alignment. Dewatering will likely be required at the entry and exit shafts depending on the shaft construction method. The main advantage of this technique is that construction typically is faster than other methods, and the project will be completed faster. Care should be taken to minimize the vibration created by the TBM and thereby minimize the deformation of granular soils below groundwater. The main disadvantage of this technology is the relatively higher cost, but it involves comparatively less risk.
Horizontal Directional Drilling (HDD) is becoming more popular for the installation of pipes, conduits and cables along a desired profile using a surface-launched drilling rig. The first step is to set up the launch site. A drilling rig is established which supplies the rotation and thrust to the drill. Additional lengths of drilling rod are than added as the drilling progresses through the bore. The drill bit should be chosen based on the type of soil to provide the most efficient progress possible as it cuts through the ground. The horizontal drilling is performed by fluid-assisted mechanical action of the cutter head. Once the drill reaches the destination point, the first phase is completed and the next step is to enlarge the bore size by pulling a reamer back through the tunnel. A drill bit is removed from the end of the drill string and is replaced with a reaming tool. A number of reaming passes may be required to open the diameter of the bore to approximately 1.5 times the diameter of proposed watermain. The pipe is pulled back through the bore in the same way as the reaming tool was used. A pulling head and swivel is then attached to the
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end of the drill string. The pipe is attached to the pulling head and slowly pulled back through the bore. The main advantage of this technique is that it can be suited to most soil conditions with minimal ground disturbance. The improvements to the technique are continuously in progress. The disadvantage of the techniques is that it can have potential to blow out. It is difficult to maintain the alignment when used in ground having a significant number of cobbles/boulders. The drilling fluid to be used for the drilling should be environmental friendly.
It should be noted that cobbles and boulders may be encountered in the glacial till deposit. Therefore, the selection of cutting tools and methods should be compatible with the subsurface conditions at this site. The rock cutter discs should be properly selected to break cobbles and boulders at the face into sufficiently smaller fragments. Some MTBMs can incorporate a crushing head to crush the cobbles and boulders while the bore is being advanced. However, due to the unknown numbers or sizes of cobbles and boulders, the MTBM may be fully obstructed. If the obstruction cannot be cleared or ingested by the machine, the alignment may have to be abandoned or a rescue shaft may be advanced to free the MTBM and remove the obstructions.
Once the excavation extends to the final grade of the shaft, it is recommended that the exposed soils should be covered with 19 mm clear crushed stone or equivalent. The clear crushed stone base should be immediately covered with a 100 mm thick concrete mud slab to protect the subgrade from disturbance from construction activities. A layer of filter fabric should be used between the subsoil and the crushed stone base to prevent erosion at the interface and ingress of fine soil particles into the crushed stone.
All construction work should be carried in accordance with the OHSA and Ontario Regulation 213/91 for Construction Projects and with local regulations.
4.2.5 Groundwater Control and Dewatering
Based on the available information from the boreholes, groundwater levels were encountered above the anticipated invert level of the pipe along proposed open cut and trenchless sections. The anticipated pipe invert depth is between 2.0 to 5.0 m below the existing surface grade for open cut section and between 7.0 to 10.0 m below the existing surface grade for trenchless section. Therefore, a groundwater control plan is required for the open cut section, including pumping from sumps. The groundwater should be lowered to a minimum of 0.5 m below the base of excavation for dry construction conditions.
Dewatering will also be required for the construction of entry and exit shafts, based on the groundwater levels encountered in boreholes BH 17-4 and BH 17-6, which were advanced at the approximate shaft locations. The impact of dewatering activities to the surrounding structures should be further evaluated during the detailed design stage. A Permit To Take Water (PTTW) from the MOECC is required when dewatering activities result in groundwater extraction in excess of 50,000 L/day.
Surficial water seepage into the excavations should be expected and will be heavier during periods of sustained precipitation. Pumping from properly filtered sumps located at the base of the excavations may be required to provide additional groundwater control. Sumps should be maintained outside of the actual excavation limits. Surface water runoff should be directed away from the excavations at all times.
For more details on groundwater levels and management, please refer to the Hydrogeology Assessment Report from AECOM. A detailed dewatering assessment and dewatering plan should be prepared / reviewed by the dewatering expert or experienced hydrogeologist, during the detailed design stage.
The water shall be disposed of so as not to be injurious to public health and safety. Dewatering operations shall be directed to a sediment control device prior to discharge.
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4.2.6 Soil Corrosivity
The sulphate (SO4) resistance of concrete in contact with the soils was evaluated by performing water-soluble sulphate test on the three (3) selected samples from BH 17-1 SS 6, BH 17-4 SS 8 and BH 17-7 SS 5. The tests indicated that the sulphate concentrations in the soil samples were between 6 and 68 μg/g or between 0.6 and 6.8%. Compared with Table 3 specified in the Canadian Standard Association (CSA) specification CSA A23.1-14, the test results show that the water-soluble sulphate content of the tested soil samples are above 0.2%, which indicated that the classes of exposure are S-1 and S-2 (severe to very severe degree of exposure). Reference should be made to the above mentioned CSA specifications for appropriate cement type. The corrosivity results are provided by AGAT Laboratories and presented in Appendix D.
The following table summarizes the soil corrosivity evaluation according to the ANSI/AWWA C105 Standard (American Water Works Association (AWWA) Standards approved by American National Standards Institute (ANSI)) for the potential of corrosion for buried grey or ductile cast iron pipe. A score of 10 points or more indicates potential for corrosion.
According to the ANSI/AWWA rating system, the soils in the vicinity of boreholes BH 17-1, BH 17-4, and BH 17-7 at the tested sample depths are considered to be not corrosive for cast iron or ductile iron pipes (3.5 to 8.5 points).
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4.2.7 Environmental Soil Test Results
The laboratory test results for the selected soil samples can be found in Appendix D.
The results of the analysis were compared with the MOECC Table 3 Full Depth Generic Condition Standards (SCS) for industrial/commercial/community property use, in a Non-Potable Groundwater Condition for fine to medium textured soil type.
The results of soil samples analyzed indicated that the concentration of all analyzed parameters met the applicable MOECC Table 3 Standards except Sodium Adsorption Ratio (SAR) value was above the MOECC Table 3 SCS in soil sample BH 17-5 SS 2.
Based on Toxicity Characteristic Leaching Procedure (TCLP) analytical results, the collected composite soil sample TCLP-1 could be classified as non-hazardous material and dispose off-site at licensed facility.
5. Closure
This report is for the preliminary geotechnical investigation and to provide preliminary geotechnical recommendations only based on the subsurface conditions encountered during the geotechnical investigation at the Project location. When the design of the watermain is finalized, the information in this report should be reviewed, and additional investigations should be carried out.
Appendix A Borehole Location Plans and Borehole Profiles
M E
TR O
LI N
X B
A R
R IE
G O
C O
R R
ID O
Distribution System
Keele Street Watermain Upgrade Not Required for Alternative 2A Long Transmission Watermain
Keele Reservoir
Fl in
d
Bratty Rd
Bowsfield Rd
Meters
Downsview Area Long Term Water Servicing Municipal Class EA Study
Geotechnical, Hydrogeological and Environ- mental Investigations
Oct,2017 1:12,500
Datum: MTM 3 Tran.Mer. Source: City of Toronto
This drawing has been prepared for the use of AECOM's client and may not be used, reproduced or relied upon by third parties, except as agreed by AECOM and its client, as required by law or for use by governmental reviewing
agencies. AECOM accepts no responsibility, and denies any liability whatsoever, to any party that modifies this drawing w thout AECOM's express written consent.
N
Region of York
Y O R K R E G I O NY O R K R E G I O N
Long Transmission Watermain - Routing Options
Legend
TERMINOLOGY USED IN BOREHOLE LOGS
Topsoil: Mixture of soil and humus capable of supporting good vegetative growth.
Peat: A mass of organic matter usually fibrous in texture in various stages of decomposition, generally dark brown to black in colour and of spongy consistency.
Fill: The term fill has been used to describe materials which have been placed by non-natural processes. Fills can often be heterogeneous in nature and those relying on this report should expect them to contain deleterious materials. Such materials can include wood, bricks, slag, porcelain, organics, and obstructions such as scrap metal, storage tanks, and abandoned concrete/steel structures.
Due to the uncertainty of the placement method of the material, the boring samples obtained for this report are not expected to represent other materials at any horizontal or vertical distance from where the sample was obtained.
Fill material may be contaminated by toxic/hazardous waste that renders it unacceptable for deposition in any but designated land fill site. Unless specifically stated, the fill on this site has not been tested for contaminants that can be considered toxic or hazardous. Testing to determine the toxicity of fill materials can be conducted, if requested.
Till: The term till on the borehole logs indicates that the material originates from a geological process associated with glaciation. Till must be considered heterogeneous in composition and containing pockets and/or seams of material such as sand, gravel, silt or clay. Till often contains cobbles (60 to 200 mm) and boulders (over 200 mm). Contractors may therefore encounter cobbles and boulders during excavation, even if they are not indicated by the logs. It should be appreciated that normal sampling equipment cannot differentiate the size or type of any obstruction. Due to the horizontal and vertical variability of till, the sample description may be applicable to a very limited zone. Caution is essential when dealing with sensitive excavations or dewatering programs in till materials.
Desiccated: having visible signs of weathering by oxidization of clay minerals, shrinkage cracks, etc.
Stratified: alternating layers of varying material or color with the layers greater than 6 mm thick.
Laminated: alternating layers of varying material or color with the layers less than 6 mm thick.
Fissured: material breaks along plane of fracture.
Varved: composed of regular alternating layers of silt and clay.
Slickensided: fracture planes appear polished or glossy, sometimes striated.
Blocky: cohesive soil that can be broken down into small angular lumps which resist further breakdown.
Lensed: inclusion of small pockets of different soil, such as small lenses of sand scattered through a mass of clay; not thickness.
Seam: a thin, confined layer of soil having different particle size, texture, or color from materials above and below.
Homogeneous: same color and appearance throughout.
Well Graded: having wide range in grain sized and substantial amounts of all predominantly on grain size.
Uniformly Graded: predominantly on grain size.
Residual: completed weathered sedimentary rock mixed with native soils.
Terminology describing soil structure
All soil sample descriptions included in this report generally follow the Canadian Foundations Engineering Manual and the Unified Soil Classification System. These systems follow the standard proposed by the International Society for Soil Mechanics and Foundation Engineering. Laboratory grain size analyses provided by AECOM follow the same system. Note that, with exception of those samples where a grain size distribution analysis has been completed, all samples have been classified by visual inspection. Visual inspection classification is not sufficient to provide exact gain sizing.
ISSMFE / USCS SOIL CLASSIFICATION
CLAY SILT SAND GRAVEL COBBLES BOULDERS F NE MEDIUM COARSE FINE COARSE
0 002 0 075 0.475 2.0 4.75 26.5 75 200
EQUIVALENT GRAIN DIAMETER IN MILLIMETRES
The standard terminology to describe cohesive soils includes consistency, which is based on undrained shear strength as measured by in-situ vane tests, penetrometer tests, unconfined compression tests or similar field and laboratory analysis. Standard Penetration Test ‘N’ values can also be used to provide an approximate indication of the consistency and shear strength of fine grained, cohesive soils.
The standard terminology to describe cohesionless soils includes the compactness condition as determined by the Standard Penetration Test ‘N’ value.
Cohesionless Soils Cohesive Soils Composition
Compactness Condition
Undrained Shear
(blows per 0.3 m) Term Criteria
Very loose 0 – 4 Very soft < 12 < 2 Trace 1% - 10% Loose 4 – 10 Soft 12 - 25 2 – 4 Some 10% - 20%
Compact 10 – 30 Firm 25 – 50 4 – 8 Adjective 20% - 35% Dense 30 – 50 Stiff 50 – 100 8 – 15 And > 35%
Very Dense > 50 Very Stiff 100 - 200 15 – 30 Noun > 35% & largest fraction Hard > 200 > 30
Standard Penetration Test (SPT):
The number of blows required to drive a 50 mm (2 in.) open split spoon sampler from a depth of 150 mm (6 in.) to 450 mm (18 in.) in undisturbed soil. Each blow is driven by a 63.6 kg (140 lb.) hammer free falling a distance of 0.76 m (30 in.).
Sample & Soil Abbreviations Contaminant Abbreviations
CORE Rock core sample BNAE base/neutral/acid extractables AS Auger sample BTEX benzene, toluene,
ethylbenzene, xylenes FV Field vane OCP organochlorine pesticides
PP Pocket penetrometer MI metals & inorganics SG Specific Gravity PAH polycyclic aromatic
hydrocarbons GS Grab sample PCB polychlorinated biphenyls
SS Split spoon sample PHC CCME petroleum hydrocarbons (fractions 1 – 4)
DCPT Dynamic cone penetration test VOC volatile organic compounds (includes BTEX)
GR Gravel Plasticity Description
SI Silt Medium 30 < wl < 50
CL Clay High 50 < wl
Strata/Graphic Plot
Explanatory Sheet To Rock Core Log
Column No. Description 1. Elevation and Depth of Geotechnical Boundary in Borehole 2. Drilling Method Used 3. General Description of Geotechnical Unit: Quantitative description including rock type (s), percentage of rock
types, frequency and sizes of interbeds, colour, texture, weathering, strength and general joint spacing Hardness H1 Extremely Hard Cannot be scratched with a pocket knife or sharp pick. Can only be
chipped with repeated heavy hammer blows H2 Very Hard Cannot be scratched with a pocket knife or sharp pick. Breaks with
repeated heavy hammer blows H3 Hard Can be scratched with a pocket knife or sharp pick with difficulty (heavy
pressure) Breaks with heavy hammer blows H4 Moderately Hard Can be scratched with a pocket knife or sharp pick with light or moderate
pressure. Breaks with moderate hammer blows H5 Moderately Soft
Can be grooved 1.6 mm (1/16 in) with a pocket knife or sharp pick
H6 Soft Can be grooved or gouged easily with a pocket knife or sharp pick with slight pressure, can be scratech with a finger nail. Breaks with light or moderate manual pressure
H7 Very Soft Can readily be indented, grooved or gouged with a finger nail, or Carved with pocket knife. Breaks with light manual pressure
Strength (from ISRM) Approx UCS Svh Very High Strength
>200 MPa
Sh High Strength 50 to 200 MPa Sm Medium Strength 15 to 50 MPa Sl Low Strength 4 to 15 MPa Svl Very Low Strength
1 to 4 MPa
4 Geological Symbol for Rock or Soil Material 5. Elevation of Geotechnical Boundary 6. Run Number: Drill run number 7. Penetration Rate: meters per min 8. Colour & Return Percentage: 9. Core Recovery: Core recovery is the total length of core pieces, irrespective of their individual lengths, obtained in a
core run and expressed as a percentage of the length of that core run. 10. Rock Quality Designation (RQD): The total length of those pieces of sound core which are 10 cm (4 inches) or
greater in length in a core run expressed as a percentage of the total length of that core run. Sound pieces of rack are those pieces separated by natural breaks and not machine breaks or subsequent artificial breaks. 0 - 25 percent Very Poor Quality 25 - 40 percent Poor Quality 40 - 75 percent Fair Quality 75 - 90 percent Good Quality 90 - 100 percent Very Good Quality
11. Fracturing: Fu Unfractured No Fractures Fvs Very Slightly Fractured Core length greater than 0.9 m (3 ft) Fsl Slightly Fractured Core length from 0.3 to 0.9 m (1 to 3 ft) Fm Moderately Fractured Core length from 0.1 to 0.3 m (4 in. to 1 ft) Fi Intensely Fractured Core lengths from 0.25 to 0.1 m (1 in. to 4 in.) Fvi Very Intensely Fractured Mostly chips and fragments
12. Degreed of dip of discontinuity measured from the axis of rock core.
13. Discontinuity Description Fracture Width (FW) FWt Tight No visible separation FWs Slightly Open FW< 0.8 mm (1/32 in.) FWm Moderately Open 0.8 mm (1/32 in.)≤FW<3.2 mm (1/8 in.) FWo Open 3.2 mm (1/8 in.) ≤FW<9.7 mm (3/8 in.) FWmw Moderatley Wide 9.7 mm(3/8 in.) ≤FW<25.4 mm (1 in.) FWw Wide FW≥25.4 mm(1 in.) Fracture Filling or Coating Thickness(FF) FFc Clean No film coating FFvt Very Thin FF< 0.8 mm (1/32 in.) FFm Moderately Thin 0.8 mm (1/32 in.)≤FF<3.2 mm (1/8 in.) FFt Thin 3.2 mm (1/8 in.) ≤FF<9.7 mm (3/8 in.) FFmt Moderately Thick 9.7 mm(3/8 in.) ≤FF<25.4 mm (1 in.) FFw Thick FF≥25.4 mm(1 in.) Roughness Rst Stepped Near normal steps and ridges occur on the fracture surface Rr Rough Large angular asperities can be seen Rm Moderately Rough Asperities are cleanly visible and fracture surface feels abrasive Rs Slightly Rough Small asperities on the fracture surface are visible and can be felt Rsm Smooth No asperities, smooth to the touch Bedding Spacing (Sb) Bm Massive ≤Sb > 3 m (10 ft) Bvt Very Thickly Bedded 0.9 m (3 ft) ≤ Sb ≤ 3 m (10 ft) Bt Thickly Bedded 0.3 m (1 ft) ≤ Sb ≤ 0.9 m (3 ft) Bm Moderately Bedded 0.1 m (4 in.) ≤ Sb ≤ 0.3 m (1 ft) Bt Thinly Bedded 25 mm (1 in.) ≤ Sb ≤ 0.1 m (4 in.) Bvt Very Thinly Bedded 6 mm (1/4 in.) ≤ Sb ≤ 25 mm (1 in.) Bl Laminated SB ≤ 6 mm (1/4 in.) Orientation Of Flat = 0 - 20o Od Dipping = 20 - 50o
Ov Vertical = 50 - 90o
Surface Shape Planar Flat surface Wavy Undulating surface Fracture Type: B Bedding J Fault C Joint F Foliation S Shear Plane M Mechanical Breaks
14. Hydraulic Conductivity (cm/sec)






























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Appendix D Corrosivity and Environmental Soil Testing Results
CLIENT NAME: AECOM CANADA LTD 5080 COMMERCE BLVD MISSISSAUGA, ON L4W4P2 (905) 238-0007
5835 COOPERS AVENUE MISSISSAUGA, ONTARIO
CANADA L4Z 1Y2 TEL (905)712-5100 FAX (905)712-5122
http://www.agatlabs.com
DATE REPORTED:
VERSION*: 1
Should you require any information regarding this analysis please contact your client services representative at (905) 712-5100
17T248892AGAT WORK ORDER:
Laboratories (V1) Page 1 of 5
All samples will be disposed of within 30 days following analysis. Please contact the lab if you require additional sample storage time.
AGAT Laboratories is accredited to ISO/IEC 17025 by the Canadian Association for Laboratory Accreditation Inc. (CALA) and/or Standards Council of Canada (SCC) for specific tests listed on the scope of accreditation. AGAT Laboratories (Mississauga) is also accredited by the Canadian Association for Laboratory Accreditation Inc. (CALA) for specific drinking water tests. Accreditations are location and parameter specific. A complete listing of parameters for each location is available from www.cala.ca and/or www.scc.ca. The tests in his report may not necessarily be included in the scope of accredita ion.
Association of Professional Engineers and Geoscientists of Alberta (APEGA) Western Enviro-Agricultural Laboratory Association (WEALA) Environmental Services Association of Alberta (ESAA)
Member of:
*NOTES
Results relate only to the items tested and to all the items tested All reportable information as specified by ISO 17025:2005 is available from AGAT Laboratories upon request
B H
-1 7-
9 SS
5 B
H -1
7- 7
SS 5
B H
-1 7-
1 SS
6 B
H 17
-4 S
S8 SA
M PL
E D
ES C
R IP
TI O
5
Corrosivity Package Sulfide (S2-) 8638269 8638269 0.16 0.16 NA