GEOTECHNICAL REPORT CBSA Facility Redevelopment Thousand Islands International Crossing Lansdowne, Ontario

Transcription

1 GEOTECHNICAL REPORT CBSA Facility Redevelopment Thousand Islands International Crossing Lansdowne, Ontario Prepared For: The Federal Bridge Corporation Limited SPL Project No.: Report Date: January SPL Consultants Limited

2 Project i Table of Contents 1. INTRODUCTION PROJECT UNDERSTANDING & SITE DESCRIPTION SCOPE OF WORK INVESTIGATION PROCEDURES Desk Study Field Investigation Laboratory Testing SUBSURFACE CONDITIONS Soil Conditions Pavement Structure Topsoil Fill Silty Clay Glacial Till Cobbles and Boulders Bedrock Groundwater Conditions Summary DISCUSSION AND RECOMMENDATIONS General Seismic Considerations Liquefaction Potential Seismic Site Classification Site Grading and Engineered Fill Site Grading Foundations Shallow Foundations on Overburden Materials or Engineered Fill Shallow Foundations on Bedrock Deep Foundations Compressive Resistance Uplift Resistance Lateral Resistance Construction Considerations Frost Protection Slab on Grade Lateral Earth Pressures Foundation Wall Backfill Permanent Groundwater Control and Basement Drainage Backfilling and Compaction Site Services Corrosion and Cement Type Pavements Preliminary Condition Pavement Survey Pavement Rehabilitation New Pavement Construction Construction Considerations Rock Removal Construction Dewatering... 29

3 Project ii Temporary Excavations Subgrade Preparation Winter Construction CLOSURE Drawings Site Plan 1 Borehole Location Plan 2 Subsurface Profile A-A 3 Grain Size Distribution 4 Plasticity Chart 5 Appendices Appendix I: Record of Augerholes, Borehole Logs and Core Photographs Appendix II: Results of Chemical Testing Appendix III: Results of MASW Testing Appendix IV: Explanation of Terms used in Report Appendix V: Limitations of This Report No.

4 Project INTRODUCTION SPL Consultants Limited (SPL) was retained by The Federal Bridge Corporation Limited to conduct a geotechnical investigation at the CBSA Thousand Island International Crossing Facility located along Highway 137 in Lansdowne, Ontario. The Terms of Reference (TOR) for this geotechnical investigation are outlined in SPL s Proposal No. P dated October 1, 2014 and subsequent project correspondence. The purpose of the geotechnical investigation was to obtain subsurface information at the site by means of exploratory augerholes and boreholes. This report presents the findings of the investigation and provides comments and recommendations related to the redevelopment of the site. 2. PROJECT UNDERSTANDING & SITE DESCRIPTION The site is located at 860 Highway 137 on Hill Island near Lansdowne, Ontario as show in Drawing No. 1. The site is currently about half developed on the western portion of the property. The current developments include several single storey buildings (vehicle inspection building, a commercial building and a FedEx shipping building), a two storey Traffic Building, eight primary inspection booths, a canopy covered secondary vehicle inspection area, a large open parking area south of the Commercial building, a smaller parking area north of the Commercial Building and other smaller associated parking areas. The eastern half of the site is wooded with numerous large undulating bedrock outcrops which are visible throughout the area. It is understood that plans are being prepared to redevelop the site. This redevelopment will generally consist of the construction of: a two storey Traffic, Commercial and Canadian Customs Building; four new canopy covered Commercial Primary Inspection lanes and booths; ten new canopy covered Traffic Primary Inspection lanes and booths with a service/access bridge above the inspection lanes; a canopy covered Traffic Secondary Inspection area; a new waste water treatment plant; a new Thousand Islands Bridge Authority (T.I.B.A.) services building; and, new parking and seizure areas. Currently, preliminary plans are being developed. The grading around the new two storey Traffic, Commercial and Customs Building will be such that the lower level will be at grade on the west side for Traffic operations (Ground Floor Finished Floor Elevation of 82.5 m) and the site will be raised around the eastern portion of the building so that the upper level will be at grade on the east side for Commercial operations (Second Floor Finished Floor Elevation of 87.0 m). The new waste water treatment plant and the new services buildings will be single storey buildings. In general, the western part of the site will remain near the existing grades, while the east part of the site will require extensive grading. In some areas in the eastern part of the site, the grade will be

5 Project lowered by as much as 8.0 m and in other areas will be raised by up to 3.5 m. Conceptual and Functional site plans of the proposed redevelopment which were available at the time of this investigation are shown in Drawing No SCOPE OF WORK The scope of work for this assignment included: A desk study and review of existing geotechnical information in the general area; Laying out the augerholes and boreholes and obtaining utility locates at the project site; Drilling of nineteen boreholes and sixteen augerholes; In-situ soil sampling and testing, including Standard Penetration Testing (SPT); Obtaining soil samples and rock core for additional review and laboratory testing; Laboratory testing; Geotechnical analysis; and Preparation of this report which presents the results of the investigation and provides geotechnical recommendations related to the design of the foundations, site services and pavements. 4. INVESTIGATION PROCEDURES The initial geotechnical investigation was carried out in October of 2014 and a second supplementary investigation was carried out in December Desk Study Bedrock geology maps of Hill Island indicate that the bedrock in the general area consists predominately of Precambrian granitic gneiss. Seams/areas of Paleozoic sandstone and Precambrian quartzite are mapped to the north and east of the site. 4.2 Field Investigation The initial field investigation was carried out on October 14, 2014 and between October 21 and October 23, 2014 and included a visual pavement condition survey and the drilling of seven boreholes and sixteen augerholes at the site. A supplementary investigation was carried out in December 2014, which included the Multi-channel Analysis of Surface Waves (MASW) and drilling of twelve boreholes at the site. The boreholes were located near or within the proposed building footprints and the augerholes were located within existing and proposed pavement areas. The boreholes and augerholes were advanced using equipment supplied and operated by George Downing Estate Drilling Incorporated of Hawkesbury, Ontario. The boreholes and augerholes were advanced using both solid and hollow stem augers to depths ranging from 0.3 m to 13.2 m below the existing ground surface. All but four boreholes after encountering auger refusal, were advanced beyond the refusal depth using N sized coring equipment.

6 Project The drilling activities were supervised by a member of SPL s geotechnical staff. In-situ tests including Standard Penetration Testing (SPT) were carried out at regular intervals. For each borehole, soil samples and rock core were logged and visually classified in the field by a member of SPL s geotechnical staff. Borehole logs and bedrock coring photographs are included in Appendix I of this report. Two monitoring wells were installed at the site to allow for the measurement of stabilized groundwater levels. The monitoring wells were installed in boreholes BH14-14 and BH All other boreholes were backfilled with bentonite and soil cuttings and were sealed at the ground surface with asphaltic concrete. The borehole locations are shown in Drawing No. 2. Approximate borehole locations were selected by EPOH and the MMM Group. SPL marked the borehole locations in the field in relation to existing site features. The as-drilled locations and the ground surface elevation at the boreholes for the initial investigation (in October 2014) were subsequently surveyed by the MMM Group. The as-drilled locations and the ground surface elevation at the boreholes for the supplementary investigation were estimated from the site plan provided. A preliminary visual pavement condition survey was carried out on October 14, 2014, which consisted of observing the existing condition of the paved areas, noting the severity and general locations of pavement distress. The MASW was carried out on December 2, 2014 along a survey line east of the existing Commercial building. The survey line ran 69 m generally in the north south direction, approximately between boreholes BH14-8 and BH14-8. The analysis generated a shear wave velocity model for the overburden and bedrock within the top 30 metres. The results of this analysis are included in Appendix III. 4.3 Laboratory Testing Upon completion of drilling and in-situ testing, soil samples were returned to SPL s laboratory for further examination, classification and testing. The laboratory testing program carried out on selected representative soil samples included the determination of natural water content, grain size distribution, and Atterberg limits (plasticity). Chemical analyses for soil corrosivity were carried out on three selected soil samples. Unconfined Compressive Strength (UCS) and whole rock analysis was carried on out on selected rock core samples. The results of natural water content tests are included on the borehole logs in Appendix I. The results of the grain size distribution testing are summarized on the individual borehole logs and presented in Drawing No. 4. The results of the Atterberg limits (plasticity) are presented in Drawing No. 5. Chemical testing to determine sulphate content, chloride content, ph and resistivity was also carried out on a selected soil samples obtained during the drilling. The results of these tests are included in Appendix II.

7 Project SUBSURFACE CONDITIONS The subsurface conditions encountered during the drilling at the site are discussed in the following sections. Detailed descriptions of the soil and groundwater conditions encountered at each of the borehole locations are included in the individual borehole and augerhole logs in Appendix I. 5.1 Soil Conditions Pavement Structure An asphaltic concrete pavement structure was encountered in all augerholes and boreholes, except in augerholes AH14-6, AH14-16 and AH14-17 and boreholes BH14-24, BH14-25, BH14-27, BH14-28, BH14-29, and BH Four general asphaltic pavement structures and one concrete pavement structure were encountered in the current investigation at the facility. The asphaltic pavements structures can be grouped by location. It appears that one pavement structure was constructed along the main northbound through corridor located between the existing Traffic Building and the existing Commercial Building (augerholes AH14-1, AH14-10, AH14-12, AH14-13, AH14-21, AH14-22, AH14-23, and borehole BH14-12A, BH14-13A and BH14-20). A second asphaltic pavement structure is generally located around the existing Commercial Building and the parking lot north of the existing Commercial Building (augerholes AH14-9, and AH14-17 and boreholes BH14-14, BH14-19, BH14-26, BH14-30 and BH14-32). A third pavement structure was encountered in the large parking lot south and east of the existing Commercial Building (augerholes AH14-2 through AH14-5, and AH14-7, and boreholes BH14-8, BH14-15, BH14-18 and BH14-31). The fourth pavement structure was encountered in the parking area on the west side of the Traffic Building in borehole BH In augerhole AH14-17, it appear that there may have been a previous asphaltic concrete surface, but only fragments of asphaltic concrete were encountered in the augerhole. The following table provides a summary of the thicknesses of asphaltic concrete pavement structure encountered in each borehole. The boreholes have been grouped by location relative to the operations and layout of the facility.

8 Project Area Main Northbound Through Corridor Paved areas surrounding Commercial Building Augerhole/ Borehole No. Table 1 Existing Asphaltic Concrete Pavement Structures Asphaltic Concrete Thickness (mm) Granular Base Thickness (mm) Area Augerhole/ Borehole No. Asphaltic Concrete Thickness (mm) Granular Base Thickness (mm) AH AH AH AH AH AH BH14-12A BH South AH AH Parking BH14-13A BH Lot BH BH AH BH AH BH AH AH BH AH BH BH BH BH14-32 NA NA West side of Traffic Building AH In all four pavement structures underlying the asphaltic concrete is granular base consisting of crushed sand and gravel. The average thicknesses for each area are summarized below: Area Main Northbound Through Corridor Paved areas surrounding Commercial Building South Parking Lot West side of Traffic Building Table 2 Average Thickness of the Asphaltic Concrete Pavement Structures Augerhole/ Borehole No. AH14-1, AH14-10, AH14-12, BH14-12A, AH14-13, BH14-13A, BH14-20, AH14-21, AH14-22, AH14-23 AH14-9, BH14-14, AH14-17, AH14-19, BH14-26, BH14-30, BH14-32 AH14-2, AH14-3, AH14-4, BH14-5, AH14-7, BH14-8, BH14-15, BH14-18, BH14-31 Asphaltic Concrete Thickness (mm) Granular Base Thickness (mm) Range Typical Range Typical AH

9 Project The grain size curve for one selected sample of the granular base is presented in Drawing No. 4 and summarized in the table below. This sample generally meets the gradation requirements for OPSS 1010 Granular A. Borehole No. Sample No. Table 3 Results of Grain Size Analyses for Granular Base Grain Size Distribution % Gravel % Sand % Fines BH14-14 GS A concrete pavement structure was visually observed at the commercial lanes of the primary inspection booths, but the composition and thickness of the concrete pavement structure was not determined as part of this assignment Topsoil A surficial layer of topsoil was encountered in augerhole AH14-16 and in boreholes BH14-25 and BH The thickness of this topsoil varied from 200 mm to 300 mm Fill Underlying the pavement structure in all the augerholes and boreholes is a layer of fill consisting of sand and gravel with varying amounts of fines (silts) and cobbles. Overall, the fill extends to a depth ranging from 0.6 m to 3.1 m below the existing pavement surface (Elevation 77.2 m to 81.3 m). In the northbound through corridor and around the existing Commercial Building, the average depth of the fill was about 1.0 m (Elevation 81.0 m), but in some areas, the fill extended to 1.5 m below the existing pavement surface (Elevation 79.8 m). In the southern parking lot, the average depth of fill was about 1.3 m (Elevation 79.4 m), but in some areas extended to 2.9 m below the existing pavement surface (Elevation 77.2 m). Near the proposed Secondary Traffic Inspection Area, the average depth of the fill was about 1.0 m below the existing ground surface, with bottom elevations varying from 83.4 m to 87.7 m. Standard penetration test N values within the fill ranged from 5 blows per 305 mm of penetration to 50 blows per 50 mm of penetration, indicating a loose to very dense state of packing, although the higher N values could reflect the presence of course gravel and cobbles, rather than the state of packing of the soil matrix. The water content in the sand and gravel fill ranged from 3 percent to 17 percent. The grain size curves for two selected samples of sand and gravel fill are presented in Drawing No. 4 and summarized in the table below. It should be noted that these grain size distribution tests were carried out on samples obtained from the flights of the augers, which does not recover coarse gravel, cobble and boulder sized particles. Because of this the grain size distributions shown on Drawing No. 3 and Table 4 may be finer overall than some portions of the materials in the field.

10 Project Borehole No. Sample No. Table 4 Results of Grain Size Analyses for Fill Grain Size Distribution % Gravel % Sand % Fines AH14-7 GS AH14-17 GS In boreholes BH14-8, BH14-12A, BH14-26, BH14-31 and BH14-32, rock fill consisting of gravel, cobble and boulder sized blasted rock was encountered underlying the upper silty sand and gravel fill. The rock fill was mainly comprised of granite and granitic gneiss rock similar to native rock in the area. This rock fill extended to depths of 0.8 m to 7.2 m below the existing pavement surface. This rock fill may also have been encountered in borehole BH14-14 also below the upper silty sand and gravel fill and extended to the top of bedrock which was encountered at 2.4 m below the existing pavement surface Silty Clay A deposit of silty clay was encountered underlying the fill and topsoil in augerholes AH14-10, AH14-13, AH14-17 and AH14-22 and in boreholes BH14-20, BH14-24, BH14-27, BH14-30, BH14-32 and BH The locations are mainly north and west of the existing Commercial Building, near the Livingston House and in the valleys between the three bedrock outcrops at the proposed Service Building and within the proposed Traffic, Commercial and Custom Building. The silty clay extended to the termination depths of the augerholes which ranged from 1.5 m to 3.1 m below the existing ground surface (Elevation 80.3 m to 79.7 m). In area north of the existing Commercial Building and within the proposed Traffic, Commercial and Custom Building (boreholes BH14-20, BH14-30 and BH14-32), the silty clay deposit was encountered underlying the sand and gravel fill and extends to depths ranging from 5.3 m to 9.2 m below the existing pavement surface (Elevations 76.0 m to 72.7 m). A subsurface profile of this area is shown in Drawing No. 3 which shows the varying depth and thickness of this silty clay deposit. The standard penetration tests carried out within the silty clay gave N values of 2 blows and 23 blows per 305 mm of penetration, indicating a firm to very stiff consistency. Atterberg limit testing was carried out on selected samples of the silty clay and resulted in plasticity index values ranging of 6 percent to 34 percent and liquid limit values ranging from 28 percent to 60 percent. These values indicate the clay has low to high plasticity. The measured water content of the silty clay ranges from approximately 9 percent and 46 percent Glacial Till At borehole BH14-20, the silty clay is underlain by glacial till. The glacial till consists of a heterogeneous mixture of gravel, cobbles, and boulders in a matrix of silty sand and sandy silt with a trace of clay. The glacial till was fully penetrated in the borehole and was 0.3 m thick and extended to a depth of 9.5 m below the existing ground surface (Elevation 73.1 m). The single SPT N value obtained in this material was 50 blows for 100 millimetres of penetration would indicate a very dense state of packing, although

11 Project this high N value could reflect the presence of cobbles and boulders, rather than the state of packing of the soil matrix Cobbles and Boulders Underlying the fill in boreholes BH14-15 and BH14-19 is a layer of cobbles and boulders primarily consisting of the native bedrock observed at the site. In borehole BH14-15, this layer of cobbles extended from 0.8 m to a depth of 1.6 m below the pavement surface (Elevation 81.2 m to 80.4 m). These cobbles and boulders could be rock fill placed during the initial grading of the site. In borehole BH14-19, cobbles and boulders were encountered from 2.3 m to 3.1 m below the existing pavement surface (Elevations 79.6 m to 78.8 m). Cobbles and boulders or possibly rock fill may have also been encountered in borehole BH14-14 from 0.9 m to 2.4 m below the existing ground surface (Elevation 80.8 m to 79.2 m). The rock core recovered from the borehole within this zone was inconclusive 1. In borehole BH14-15 from 0.8 m to 1.6 m below the existing pavement surface (Elevation 81.2 m to 80.3 m) sand and cobbles was also encountered. Cobbles and boulders were also encountered in borehole BH14-25 below the sand and gravel fill and extended from 1.4 m to 2.0 m below the existing ground surface (Elevations 79.8 m to 79.2 m). A boulder was encountered in borehole BH14-27 below the silty clay and extended from 2.2 m to 2.4 m below the existing ground surface (Elevations 79.8 m to 79.2 m) Auger Refusal Practical refusal to augering was encountered at depths ranging from approximately 0.3 m to 9.3 m below existing pavement or ground surface (i.e., Elevation 73.2 m to 86.3 m). Auger refusal may indicate the bedrock surface, however, it could also represent cobbles and/or boulders in/or rock fill. A summary of auger refusal is given in Table 5 below. 1 Assuming that the original grading used the material from the cut areas to raise the fill areas, the rock fill would be identical in nature to the existing native rock. In these cases, differentiating between highly fractured rock and very dense rock fill can be very difficult.

12 Project Table 5 Auger Refusal Summary Area Augerhole/ Borehole No. Auger Refusal Depth (m) Auger Refusal Elevation (m) Area Augerhole/ Borehole No. Auger Refusal Depth (m) Auger Refusal Elevation (m) Main Northbound Through Corridor Proposed Traffic, Commercial and Customs Building AH BH AH South BH BH14-12A Parking Lot BH AH BH BH14-13A Proposed BH Service BH Building AH Proposed BH Traffic AH Secondary BH AH Inspection BH BH Proposed Traffic, BH BH Commercial BH BH and Customs BH Building BH Bedrock Bedrock was proven in all the boreholes except for boreholes BH14-5, BH14-12A, BH14-15 and BH The depth to bedrock varied drastically between borehole locations and ranged from at ground surface to 10.1 m below the existing surface elevation (Elevation 92.0 m to 73.1 m). An example of these drastic changes are shown on Figure 3, where the bedrock surface drops from 0.8 m below the existing ground surface to 10.1 m below the existing ground surface within 30 metres horizontally. The bedrock was cored using N sized coring equipment. Four types of bedrock were encountered at the site; granite and granitic gneiss having a pink or rose colour, diabase having a dark grey colour and migmatite which is a mixture of both granitic gneiss and diabase which have been partially melted and folded together into several layers of varying thickness. All bedrock types were found to be fresh to slightly weathered, medium to fine grained with varying degrees of fracturing (ranging from moderately close to very closely spaced fractures). Some vertical and near vertical fractures were also noted. Most fractures had water staining and soil infilling, which suggests groundwater flow through the fractures. The Rock Quality Designation (RQD) measurements of the rock range from 0% to 100% indicating very poor to excellent rock quality. Photos of the retrieved rock core are provided in Appendix I.

13 Project The laboratory test results on select of core samples of the bedrock indicate bedrock compressive strengths ranging from 62 MPa to 159 MPa, and are summarized below. Table 6 Unconfined Compressive Strength of Rock Core Samples Borehole Depth (m) Bedrock Type Unit Weight (kn/m 3 ) Unconfined Compressive Strength (MPa) BH Granitic Gneiss BH Granitic Gneiss BH Migmatite * BH Migmatite BH Migmatite BH Granitic Gneiss BH Granitic Gneiss BH Migmatite BH Migmatite BH Granitic Gneiss BH Diabase BH Diabase BH Migmatite BH Migmatite BH Migmatite BH Migmatite * BH Migmatite BH Migmatite BH Migmatite Note: * Broke along an existing fractures and may not be representative of the compressive strength of the intact rock. Three rock core samples were submitted to SGS Canada Inc. (SGS) for whole rock analysis to determine the mineral composition of the rock core. The results of these tests are included in Appendix II and summarized in the table below. Four additional rock core samples from the supplemental investigation have been submitted to SGS for additional whole rock analysis. The results will be provided in an addendum to this report. Borehole Table 7 Summarized Results of Whole Rock Analysis Testing Depth SiO Bedrock Type 2 Al 2 O 3 Fe 2 O 3 MgO CaO (m) (%) (%) (%) (%) (%) Na 2 O (%) BH Granitic Gneiss BH Granitic Gneiss BH Granitic Gneiss K 2 O (%)

14 Project Groundwater Conditions Monitoring wells were installed in boreholes BH14-14 and BH14-20 during the field investigations. The water levels within the monitoring wells were measured 1 to 3 days after completion of drilling (in October 2014) and found to be 3.4 m and 4.4 m below the existing ground surface, respectively. These wells were purged dry after installation. During the field investigation, two other monitoring wells (installed previously by others) were encountered and the water levels in these wells were also measured. The table below summarizes the groundwater observation made during the field investigation. Area Table 8 Groundwater Observations Monitoring Well Existing Ground Elevation (m) Observed Groundwater October 23, 2014 December 19, 2014 Depth (m) Elevation (m) Depth (m) Elevation (m) North of Traffic Building MW2 82.3* * Dry - North of Commercial Building BH South Parking Lot BH MW1 81.1* * Note: * denotes approximate elevations It should be noted that the groundwater levels can vary and are subject to seasonal fluctuations as well as fluctuations in response to major weather events. 5.3 Summary A summary of the soil and bedrock conditions encountered at the site are presented in the table below.

15 Project Table 9 Simplified Stratigraphy and Groundwater Elevations Augerhole Simplified Stratigraphy (Depths in metres) Borehole Cobbles Notes Pavement Silty Bedrock No. Fill Glacial Till & Structure Clay (Cored) Boulders AH Auger Refusal at 0.6 m AH Auger refusal at 1.5 m AH AH BH Auger refusal at 2.8 m AH AH BH AH AH AH AH Auger Refusal at 0.9 m BH14-12A AH BH14-13A BH EL. 78.3m BH Auger Refusal at 1.62 m AH Topsoil: 0.0 to 0.2 m AH BH BH BH EL m AH Auger Refusal at 0.90 m AH Auger Refusal at 2.40 m AH Auger Refusal at 0.45 m BH BH Topsoil: 0.0 to 0.3 m BH BH BH BH BH BH BH BH

16 Project DISCUSSION AND RECOMMENDATIONS 6.1 General This section of the report provides engineering guidelines related to the geotechnical design aspects of the project based on our interpretation of the available information described herein and project requirements. Contractors bidding on or undertaking the works should examine the factual results of the investigation, satisfy themselves as to the adequacy of the factual information for construction, and make their own interpretation of the factual data as it affects their proposed construction techniques, schedule, safety, and equipment capabilities. Reference should be made to the Limitations of this Report, attached in Appendix V, which follows the text but forms an integral part of this document. The general subsurface conditions encountered in the augerholes and boreholes include an asphaltic concrete pavement structure overlying a layer of sand and gravel fill. The average fill thickness was approximately 1.1 m, but varied from 0.6 m to 3.1 m below the existing pavement surface. A variety of materials were encountered below the sand and gravel fill. These materials included silty clay fill, rock fill, silty clay, cobbles, boulders and bedrock. Granite, granitic gneiss, diabase and migmatite bedrock were proven (cored) in all but four boreholes below auger refusal. 6.2 Seismic Considerations Liquefaction Potential A preliminary assessment for seismic liquefaction has been carried out for this site based on the subsurface conditions and the results of the SPT testing. Seismic liquefaction is the sudden loss in stiffness and strength of soil due to the loading effects of an earthquake. Liquefaction can cause significant settlements and structural failure. The analysis followed the method set forth in the Canadian Foundation and Engineering Manual, 2006 (CFEM). For the analysis, an earthquake for the project area with a 2% probability of exceedance in 50 years was assumed. Calculations Factor of Safety against Liquefaction (FSL) with depth were developed for the site based on the SPT N values collected within the soils at the site. The analysis indicates that the soils at the site are not susceptible to liquefaction Seismic Site Classification As outlined in the 2012 Ontario Building Code, building foundations must be designed to resist a minimum earthquake force. Since there are a variety of founding conditions at the site, several site classifications for seismic site response are present. In accordance with Table A of the 2012 Ontario Building Code, the seismic site response for foundations placed on either engineered fill rock fill, cobbles and boulders or stiff silty clay would have a site classification of Class C. Foundations placed on rock or near rock would have a site classification of Class B provided that there is less than 3 metres of overburden materials between the underside of the foundation and the underlying bedrock surface. In Appendix III, the results of the Multi-Channel Analysis of Surface Waves (MASW) carried out at the site indicate that the average shear wave velocity for the upper 30 metres is 1,028 m/s, which indicates

17 Project that the Site Class B would be appropriate for this site. However, the Ontario Building Code states that for a Site Class B, foundations either must bear on bedrock or be founded within 3 metres of the bedrock surface. For most of the proposed structures at the site, the founding levels are anticipated to greater than 3 m from rock, therefore a lower site class would be more appropriate. The site classifications for Seismic Site Response for each building bearing on the anticipated founding conditions are summarized below: Proposed Building Traffic, Commercial & Customs Building Temporary Commercial Building New Waste Water Plant New Services Building Table 10 Summary of Seismic Site Classifications Anticipated Founding Elevation (m) Ground Floor Foundations at EL 81.0 or lower* and Upper Floor Foundations at EL 86.5 or lower Ground Floor Foundations above EL 81.0 or Upper Floor Foundations above EL 86.5 Anticipated Founding Material Bedrock or near bedrock Existing soils or Engineered Fill Seismic Site Classification 80.8 or lower Silty Clay C 82.7 or lower Engineered Fill C 82.2 or lower Engineered Fill C Note: * The bedrock elevation varies drastically within the building foortprint and in the center portion of the building a deep clay deposit is present. Therefore a Site Class B will only be appropriate in some location. In other locations a site classification based on the presence of silty clay would be appropriate. ** A seismic site class B is only appropriate if the foundations are either bearing on the bedrock or within 3 m of the underlying bedrock. 6.3 Site Grading and Engineered Fill Site Grading At this time, functional and conceptual grading details of the proposed redevelopment are available. These plans indicate that the western portion of the site (currently developed) will remain at or near its existing grade. The plans indicated that the eastern portion of the site will require significant grading with excavations as deep as 8.0 m and fills reaching 3.5 m. Currently the eastern portion of the site is anticipated to consist of undulating bedrock with soil filled valleys. At the augerholes and boreholes advanced at four select locations, stiff silty clay was encountered within the bedrock valleys. The silty clay which is present in boreholes BH14-20, BH14-30 and BH14-32 and present at other locations at the site could have the potential to settle under the weight of the new fill placed within in B** C

18 Project the valleys to grade the site. For preliminary design, the site can likely accept the additional 3.5 m of earth or rock fill without excessive settlement. The proposed site grading plans should be reviewed during detailed design to ensure that the magnitude of the grade raise is appropriate for the sub-surface conditions encountered. Additional guidance can be provided based on preliminary site grading plans. It is understood that the grade will be raised within the existing southern parking lot area. It is recommended that the existing asphaltic concrete pavement in areas that are currently paved and are to be filled, be either pulverized and compacted or completely removed prior to the placement of any site fill. Topsoil, organics, deleterious materials and any other unsuitable materials should be removed prior to any placement of fill Engineered Fill Building Areas In areas of the site where a building is proposed and the site is required to be raised above the existing grade, these areas need to be constructed using engineered fill. Engineered fill should be constructed of either OPPS Granular A or OPPS Granular B Type I or II. The engineered fill should extend one metre beyond the limits of the foundations at the founding level and would then extend downward at a 1 horizontal to 1 vertical slope to the required depth. Prior to placing the engineered fill, the subgrade should be proofrolled to identify any loose or soft areas. This proofrolling should be observed by a licensed geotechnical engineer. The engineered fill should be placed in maximum 300-millimetre thick lifts and should be compacted to at least 98 percent of the material s standard Proctor maximum dry density (SPMDD) using suitable vibratory compaction equipment. The placement and compaction should be observed and confirmed by a professional geotechnical engineer or a materials technician acting under the supervision of a professional geotechnical engineer Engineered Fill Pavement Areas and other General Areas In areas of the site that require to be raised above the existing grade and are outside of the proposed building areas should be constructed using engineered fill. The engineered fill should consist of either earth borrow or rock borrow in accordance with OPSS 212. This fill should be placed and compacted in in accordance with OPSS 206. Prior to placing the engineered fill, the subgrade should be proofrolled to identify any loose or soft areas. This proofrolling should be observed by a professional geotechnical engineer. The placement and compaction should be observed and confirmed by a professional geotechnical engineer or a materials technician acting under the supervision of a professional geotechnical engineer. 6.4 Foundations In general, the subsurface conditions, despite being quite variable across the site, appear to be suitable to support the proposed buildings and retaining walls using shallow foundations bearing on either

19 Project engineered pads, native soils or bedrock. Each proposed building has its own unique founding condition, since the subsurface condition varying across the site and the site will have significant cuts and fills. The following founding conditions are anticipated at each proposed structure. Proposed Building Traffic, Commercial & Customs Building Traffic Primary Inspection Booths and Access Bridge Traffic Secondary Inspection Canopy Temporary Commercial Building Table 11 Anticipated Foundation Levels and Bearing Conditions Anticipated Founding Elevation (m) Ground Floor Foundations at EL 81.0* or lower and Upper Floor Foundations at EL 86.5 or lower Ground Floor Foundations above EL 81.0* or Upper Floor Foundations above EL or lower Anticipated Founding Material Bedrock Engineered Fill, Existing Soils or partial Bedrock Existing Rock Fill or Silty Clay 83.0 or lower Bedrock Existing Subgrade Conditions Fill and Silty Clay over varying bedrock contact Rock Fill and Silty Clay Fill and Silty Clay over bedrock 80.8 or lower Existing Silty Clay Silty Clay New Waste Water Plant 82.7 or lower Engineered Fill New TIBA Services Building 82.2 or lower* Engineered Fill and partial Bedrock Note: * The bedrock elevation varies drastically within these buildings with deep clay deposits present within the bedrock valleys. Cobbles and Boulders Fill over Bedrock All bearing surfaces should be checked, evaluated and approved at the time of construction by a geotechnical engineer who is familiar with the findings of this investigation and the design and construction of similar projects prior to placement of any concrete, back fill, etc. Additional guidance related to bearing resistances can be provided based on detailed designs. In particular, bearing resistances should be reviewed if the founding elevations are different than indicated in this report or if the foundation loads are too large for the assumed shallow foundation sizes Shallow Foundations on Overburden Materials or Engineered Fill Based on the results of the subsurface investigation, it appears that the foundations for the proposed buildings (with the expectation of new Traffic, Commercial and Customs Building and the Canopy for the Traffic Secondary Inspection Area) and retaining walls would be supported on either native subgrade soils, existing cobbles and boulders (possibly rock fill) or newly constructed engineered fill. For these structures, the shallow foundations (spread footings, strip footings, etc.) placed on the properly

20 Project prepared subgrades with a footing width between 0.6 m and 2.0 m, the following bearing resistances may be assumed provided any grade raise above the existing grade is equal to or less than 3.5 m: The unfactored ultimate geotechnical bearing resistance can be taken as 400 kpa. A resistance factor of 0.5 should be applied to this value, yielding a factored bearing resistance of 200 kpa at ULS (Ultimate Limit States). The geotechnical resistance at the Serviceability Limit State (SLS) can be taken as 100 kpa. Provided that the foundation subgrade is properly prepared, and not unduly disturbed by construction activities, total and differential settlements associated with the above SLS resistance values are expected to be less than 25 mm and 20 mm, respectively. The prepared subgrade should be confirmed by a professional geotechnical engineer or a materials technician acting under the supervision of a professional geotechnical engineer prior to constructing the foundations. The upper 300 mm of the existing silty sand and gravel fill should be recompacted to 98 percent of the material s standard Proctor Maximum Dry Density (SPMDD) using suitable vibratory compaction equipment. The placement and compaction should be observed and confirmed by a professional geotechnical engineer or a materials technician acting under the supervision of a professional geotechnical engineer. If the foundations were to be placed on the existing rock fill or cobbles and boulders, then the upper portion of these materials should be blinded or chinked with 150 mm of compacted OPPS Granular A compacted to at least 98 percent of the material s standard Proctor maximum dry density using suitable vibratory compaction equipment Shallow Foundations on Bedrock In considering the depth to bedrock across the proposed Traffic, Commercial and Customs Building area and the proposed T.I.B.A. Service Building, it is considered that a portion of these proposed structures could be founded on spread footings bearing directly on or within the bedrock. However as previously mentioned, the bedrock contact elevation varies quite widely and rapidly within these proposed structures. Footings placed directly on the bedrock surface and having adequate frost protection (see Section 6.5) may be sized using a preliminary Ultimate Limit States (ULS) factored bearing resistance of 1,200 kpa. Provided the bedrock surface is properly cleaned of soil at the time of construction, the settlement of footings sized using this factored bearing resistance should be negligible, and therefore Serviceability Limit States (SLS) need not be considered. A higher bearing resistance of 3,000 kpa may be used if the foundations are located in sound unweathered bedrock. However, this would require the upper 2 m of the bedrock (approximately Elevation 79.0 m) which may be highly weathered or highly fractured to be removed until sound competent bedrock is encountered.

21 Project Since the founding level for these buildings may vary across the buildings, the prepared subgrade should be confirmed by a professional geotechnical engineer Deep Foundations As previously indicated the bedrock at the site varies drastically and the valleys within the bedrock are filled with silty clay. These valleys are located within the proposed Traffic, Commercial and Customs Building and the proposed T.I.B.A. Service Building. If a higher bearing resistance is desired for these buildings then the foundations located in the silty clay deposits would need to extend to the underlying bedrock by the use of deep foundations (piles). The most cost-effective type of deep foundation for this site is likely to be a driven pile foundation. There are two types of driven steel piles commonly used in the area: H-piles; and Concrete filled, closed ended, steel pipe piles Compressive Resistance Steel piles should be driven to rock which was encountered approximately 5 m to 10 m below the existing ground surface within the bedrock valley at the proposed Traffic, Commercial and Customs Building. The bedrock elevation within the valley at the proposed T.I.B.A Service Building could not be determined, but is anticipated to be within 15 m of the existing ground surface. Piles driven to rock typically generate high ultimate geotechnical capacities, generally equal to or in excess of the structural capacity of the steel section. For the purposes of design, the ultimate geotechnical resistance may be assumed to be equal to the ultimate structural resistance of the steel section. A resistance factor of 0.4 should be applied to this value to obtain the factored geotechnical resistance of a pile driven to rock. As an example, an HP310x79 has an ultimate structural resistance of 3,490 kn (based on the crosssectional area and assuming 350 MPa yield strength, and ignoring buckling, bending, lateral loads, etc. or any other more complex situations which may reduce the structural capacity). The factored geotechnical resistance of an HP310x79 driven to rock can therefore be assumed to be 1,395 kn (0.4 x 3,490). Settlements for piles driven to rock are generally negligible, and the geotechnical resistance mobilized at 25 mm of settlement (SLS) would normally exceed the factored axial resistance at ULS. Geotechnical SLS considerations therefore do not generally govern the design of piles driven to rock Uplift Resistance The uplift resistance of a pile will be as a result of skin friction acting along the surface area of the embedded pile.

22 Project The unfactored shaft resistance (q s ) is equal to: where: q s = S u q s = the unfactored shaft resistance (in kpa) = a shaft resistance factor based on soil type (use 0.7) S u = the undrained shear strength of the soil (use 80 kpa) A resistance factor of 0.3 should be applied to this value, to obtain the factored geotechnical uplift resistance. The dead weight of the pile itself (with an appropriate structural resistance factor for dead weight) may also be added to the geotechnical resistance in calculating the total uplift resistance. The total uplift resistance of a pile group is the lesser of the sum of the individual pile resistances as described above, or the resistance of a single block of soil with a perimeter equal to the perimeter of the pile group (the mass of the soil inside the block may be included in the calculation; use a soil weight of 17 kn/m 3 ). SPL should review the preliminary pile design geometry and design and provide additional comments as appropriate. It should be noted that the uplift resistance is highly dependent upon the installation of the piles as well as the layout of the pile groups. If the piles are used to resist significant uplift loads (and uplift governs the overall design) consideration may be given to carrying out a tension test to confirm the uplift capacity Lateral Resistance The lateral resistance of long piles is typically governed by limiting the deflection which will occur under loading to some acceptable level. The geotechnical parameter most commonly used to determine lateral deflection of piles is the coefficient of horizontal subgrade reaction (k h ). For this site k h may be assumed to be: k h = 67 S u Where: k h = the modulus of subgrade reaction (kn/m 3 ); S u = undrained shear strength (use 80 kpa ); This parameter is associated with acceptable deflections, and therefore represents an unfactored SLS value. The value above is for a single pile. Group interaction must be considered when piles are spaced closely together. Group effects may be accounted for by reducing the coefficient of horizontal subgrade reaction (k h ) by an appropriate factor as follows:

23 Project Table 12 Coefficient of Horizontal Subgrade Reaction Reduction Factors Pile Spacing in Direction of Loading Reduction Factor (d = pile diameter) 8d d d 0.25 Values for other spacings may be interpolated from the above. No reduction is required for the first row of piles (i.e. the row which bears against undisturbed soil with no piles in front) Construction Considerations The piles will be driven to bedrock (which is expected to vary from 5 m to 10 m below the proposed founding level of Elevation m). Pipe piles should be driven closed-ended. All piles (pipe or H-piles) should be driven with appropriate driving shoes to prevent damage during driving. Some allowance should be made for wasting of piles which become damaged or for reduced design capacities for piles which cannot be successfully driven to rock. Appropriate piling equipment and hammers capable of generating sufficient driving energy will be required to drive the piles to rock and mobilize the full geotechnical resistance of the pile. Allowance should also be made for re-striking a portion of the piles a minimum of 2 days after initial driving to confirm that relaxation has not occurred. Significant penetration into the bedrock is not expected. The piling specifications should be reviewed by SPL prior to tender, as should the contractor s submission (i.e. shop drawings, equipment, procedures and preliminary set criteria) prior to construction. Preliminary pile driving criteria should be established prior to construction using wave equation analysis (WEAP or similar) or other approved means and confirmed through a program of dynamic testing (PDA Testing) carried out at an early stage in the piling program. Additional PDA testing should be used to confirm the pile capacities at regular intervals as the project progresses. A properly planned and executed PDA testing program would also justify increasing the geotechnical resistance factor from 0.4 to 0.5. All piling operations should be supervised on a full-time basis by SPL to monitor pile locations, plumbness, pile set, re-striking, etc. and to confirm that the design and construction of the piles is as anticipated in preparing the recommendations included in this report. 6.5 Frost Protection All exterior footings and any footings located in unheated portions of the proposed buildings and retaining walls shall be protected against frost heave by providing a minimum of 1.3 m of earth cover or the thermal equivalent if insulation is used in areas where snow will remain during winter months. In areas where the exterior grade is cleared during the winter months and exposed to freezing temperature, such as sidewalks, paved areas, etc. foundations in these areas should be provided with a minimum of 1.6 m of earth cover or the thermal equivalent if insulation is used.

24 Project The bedrock encountered in the boreholes at the site contain water filled fractures and also the presence of frost susceptible materials in the joints and seams within the bedrock. Therefore, the bedrock at the site is considered to be potentially frost susceptible and the following two options may be considered for foundation design: Option 1. Found the perimeter building footings directly on the bedrock and provide at least 1.3 metres of earth over for frost protection purposes; and, Option 2. Where 1.3 metres of earth cover cannot be provided without removing excessive amounts of bedrock and/or extensively raising the surrounding grade, the required frost protection can be achieved by insulating the footing with high density rigid insulation. In the event that foundations are to be constructed during the winter months, foundation soils and side slopes of excavations are required to be protected from freezing temperatures using suitable construction techniques. Therefore, the base and sidewalls of all excavations should be insulated from freezing temperatures immediately upon exposure, until the time that heat can be supplied to the building interior and/or the foundations have sufficient earth cover to prevent freezing of the subgrade soils. 6.6 Slab on Grade For predictable performance of the floor slab, the existing topsoil should be removed from within the proposed building area and/or the existing fill material be recompacted to 98 percent of the material s standard Proctor maximum dry density using suitable vibratory compaction equipment. Provision should be made for at least 150 millimetres of Ontario Provincial Standard Specification (OPSS) Granular A to form the base for the floor slab. Any engineered fill required to raise the grade to the underside of the Granular A should consist of OPSS Granular B Type I or II. The underslab fill should be placed in maximum 300-millimetre thick lifts and should be compacted to at least 98 percent of the material s SPMDD using suitable vibratory compaction equipment. 6.7 Lateral Earth Pressures The lateral earth pressure acting on below-grade walls, retaining walls, etc. may be calculated using the following expression: P = K( h+q) Where P = lateral earth pressure (kpa) acting at depth h K = earth pressure coefficient; for unrestrained walls and structures where some movement is acceptable (such as retaining walls) use a coefficient of active earth pressure (K a ) equal to 0.3, for restrained walls (such as basement walls) use the coefficient of earth pressure at rest (K 0 ) equal to 0.5 = the density of the backfill; use 21.5 kn/m 3 for compacted granular backfill

25 Project h = the depth to the point of interest (m) q = the magnitude of any design surcharge at the ground surface; The above values assume free-draining granular backfill will be used. If this is not the case then the above values may need to be adjusted based on the soil type used, and water pressures should be considered in the calculation of lateral pressures. SPL can provide additional guidance based on actual building plans if required. The passive resistance offered by the foundation wall backfill soils could also be considered in evaluating the lateral resistance applied to the foundations. The magnitude of that lateral resistance will depend on the backfill materials and backfill conditions adjacent to the foundation walls. If the backfill materials consist of compacted sand or sand and gravel (OPSS Granular B Type I) as discussed herein, then the passive resistance acting on the foundation wall may be taken as: where: h (z) h (z) = K p ( z+q) = lateral earth resistance applied to the foundation wall at depth z, kilopascals K p = passive earth pressure coefficient, use 3.0 = unit weight of retained soil, use 21.5 kn/m 3 z = depth below top of wall, metres q = the magnitude of any design surcharge at the ground surface; This resistance is provided in unfactored format. Factoring of the calculated resistance value will be required if the design is being carried out using Limit States Design. Movement of the backfill and wall is required to mobilize the passive resistance. As a preliminary guideline, about 75 millimetres of movement would be required. Earth pressures will be higher under seismic loading conditions. In order to account for seismic earth pressures the total earth pressure during a seismic event (including both the seismic and static components) may be assumed to be: h (z) = K a z + (K AE K a ) (H-z) Where h (z) = the total earth pressure at depth z (kpa); K a = the active earth pressure coefficient (0.3); = the unit weight of soil (21.5 kn/m 3 for granular fill or 19 kn/m 3 for native soils); K AE = the combined active earth pressure and seismic earth pressure coefficient (use 0.8); H = the total height of the wall (m) z = the depth below the top of the wall (m)

26 Project The above earth pressure values (both static and seismic) are unfactored values. 6.8 Foundation Wall Backfill Some of the soils (silty clay) at this site are potentially frost susceptible and should not be used as backfill against exterior or unheated foundation elements (e.g., footing, foundation walls, pile caps, etc.). To avoid problems with frost adhesion and heaving, these foundation elements should be backfilled with one or more of the following: Non-frost-susceptible sand and/or gravel which meets that gradation requirements for OPSS Granular B Type I; Stiff silty clay, provided that a bond break consisting of 3 sheets of 10 mil polyethylene sheeting is placed between the backfill and the foundation elements. 19 millimetre clear crushed stone having a unit weight not exceeding 21.5 kn/m 3, which is separated from other soils with a Class II non-woven geotextile having an FOS not exceeding 100 microns to prevent loss of adjacent sand, or silty soils into the clear stone. It should be noted that the use of clear stone as foundation backfill may lead to unfavourable growing conditions for plant matter placed in overlying topsoil. In areas where pavement or other hard surfacing will be in contact with the buildings, differential frost heaving could occur between the granular fill (if sand or crushed stone is used) and other areas. To reduce this differential heaving, the backfill adjacent to the wall should be placed to form a frost taper. The frost taper should be brought up to pavement subgrade level from 1.5 metres below finished exterior grade at a slope of 3 horizontal to 1 vertical, or flatter, away from the wall. The fill should be placed in maximum 300-millimetre thick lifts and should be compacted to at least 95 percent of the material s standard Proctor maximum dry density using suitable vibratory compaction equipment. 6.9 Permanent Groundwater Control and Basement Drainage The groundwater level at the site was found to be between about elevation 78.7 m and 76.0 m. If basements, sumps or other open below grade structures are planned below this elevation, they could intercept the groundwater table and should be provided with adequate drainage. Once the basement, sump and other below grade elevations are determined, the need for permanent groundwater control should be reviewed during detailed design. Basement drainage, however would typically include subdrains below the basement floor and perimeter drains around the exterior of the basement. Based on the water staining on the fractures observed on the rock core retrieved during the current investigation significant amounts of water maybe present below the groundwater elevation Backfilling and Compaction Backfill for foundation excavations and any below grade structures should comprise free draining Granular A or B materials. Backfill should be placed in shallow lifts, not exceeding 200 mm loose

27 Project thickness, and compacted to 98% SPMDD where it is supporting any structures or services, or 95% in other areas. The majority of the existing granular fill appears to meet the requirements of either OPPS Granular A or B materials. If it is chosen to reuse the existing granular fill, then it is recommended that these materials be segregated when excavated, stockpiled and further material testing be carried out on the stockpile material to confirm that is meet the OPPS aggregate requirements. The suitability of imported materials should be confirmed prior to placement from both a geotechnical and environmental perspective. Portions of the existing soils at the site are adequate for use as general earth fill, but may require moisture conditioning (either wetting or drying) prior to placement and compaction. To avoid damaging or laterally displacing the structures, care should be exercised when compacting fill adjacent to new structures. Heavy equipment should be kept a minimum of 1 m away from the structure during backfilling. The 1 m width adjacent to the wall should be compacted using handoperated equipment unless otherwise authorized Site Services Excavations up to approximately 1.0 m below the existing ground surface would be primarily within the existing sand and gravel fill. Excavations deeper than this may extend into a variety of materials ranging from silty clay, sand and gravel fill, rock fill, cobbles and boulders and bedrock. Details of the proposed site services are not available at this time; however it is assumed that they will include localized trenches throughout the site. Trenches within overburden materials can be temporarily supported using sloped excavations (see Section ) or trench boxes. It is expected that bedrock removal may be required for some site services for this project and will be carried out using drill and blast techniques. Mechanical methods of rock removal (such as hoe ramming), can likely be carried out for depths of about one metre, however, this work would likely be slow and tedious. Bedding for site services should be in accordance with the relevant OPSD standard drawing and would typically consist of Granular A compacted to 95% SPMDD. Where wet or disturbed conditions are encountered in the base of the trench it may be necessary to over-excavate and replace unsuitable soils with compacted granular fill to provide a stable sub-grade for the bedding. The use of clear stone as a bedding and cover material is not recommended as the finer particles of the native soils and backfill may migrate into the voids of the clear stone, resulting in loss of pipe support. Cover material above the spring line should consist of Granular A or Granular B material with a maximum particle size of 25 mm. Cover material should be compacted to a minimum of 95% SPMDD. Backfill may consist of additional granular fill, or the stiff weathered silty clay and should be compacted to 95% SPMDD (98% if below structures). Where backfill is below paved areas (such as access lanes and parking lots) and is within the frost depth, the backfill profile (above the minimum cover required) in the trench should be made to match the native soils on either side as much as is practical in order to

28 Project minimize the potential for differential frost heave. As a result, portions of the weathered silty clay above the water table may be retained, moisture conditioned (if necessary) and re-used. Any service trenches which extend below the water table should have clay cut-offs installed across the trench at regular intervals (typically every 100 m) to prevent the trench acting as a drain and lowering the groundwater table in the general area. These cut-offs should extend the full width of the trench and must completely penetrate the bedding, cover and any other granular materials in the trench. The above are general guidelines for typical site services. All service installations should be completed in accordance with the relevant OPSS s and OPSD s for the particular application and size. SPL can provide additional review during detailed design based on the actual services proposed if required Corrosion and Cement Type Three samples were submitted to Exova Accutest for testing related to soil corrosivity and potential exposure of concrete elements to sulphate attack. The results of these tests are included in Appendix II and summarized in the table below. Borehole/ Sample No. Table 13 Results of Soil Corrosivity Testing Electrical Chloride Soil Type Conductivity (%) (ms/cm) ph Resistivity (ohm-cm) Sulphate (%) AH14-3/SS3 Sand & Gravel FILL ,780 <0.01 BH14-18/GS1 Crushed Sand & Gravel Granular Base ,880 <0.01 BH14-20/SS2 Sand & Gravel FILL ,260 <0.01 The soil resistivity values measured in the native silty clay soils suggest a low to moderately corrosive environment for buried steel elements. The soil resistivity values within the underlying native silty sand suggest a slightly corrosive environment for buried steel elements. These values must be taken into consideration during designed below-grade steel elements, such as piling and underground services. The test results indicate a low soluble sulphate content and sulphate resistant Portland cement is not required Pavements Preliminary Condition Pavement Survey A preliminary visual condition survey was conducted within the existing paved areas along the northbound direction within the facility, the paved and parking areas around the existing Commercial Building and the southern parking lot. The purpose of this survey was to determine if there was an opportunity for salvaging the existing pavement structure or the need for a complete reconstruction of the existing paved areas.

29 Project The result of this preliminary conditions survey indicated that the majority of the existing pavements are in relatively good to fair condition with the exception of the parking area north of the existing Commercial Building. The parking area north of the existing Commercial Building is in fair to poor condition with numerous closely spaced serve distresses. The majority of the pavement distresses observed were non-structural distresses consisting of widely spaced longitudinal and transverse cracking. The degree of this cracking ranged from moderate (6 mm to 19 mm wide) to severe (greater than 19 mm). Minor to moderate raveling of the surface course was observed throughout the paved areas, especially along the northbound through corridor. Ravelling is when small amounts of aggregate have worn away from the surface course. Shallow potholes were also noted in some the paved areas. Utility trench patches were also noted throughout the paved areas especially leading to the Primary Inspection Lanes, to and from the Commercial Building and on the north side of the Commercial Building. A short section (less than 10 metres) of pavement just beyond the concrete pavement structure at the existing Primary Inspection Lanes in the commercial lanes (truck lanes) exhibited minor to moderate (up to 20 mm) degree of rutting within the wheel paths Pavement Rehabilitation Based on the finding of the preliminary condition survey (and assuming traffic loading remains similar in the various areas), it appears that the existing pavement not exposed to construction activities can remain in place after the redevelopment with minor and routine maintenance. The existing pavements exposed to construction traffic and activities may not be adequate to withstand the loading and traffic turning movements, may need extensive repair or replacement after construction. Repairs to the existing pavement outside of the construction area would generally consist of crack sealing, pothole repair and a surface treatment to seal the pavement surface, fill minor surface irregularities and would address the raveling and oxidation of the surface course. Surface treatments, such as slurry seals or mirco-surfacing could be carried out on the existing surface course which would extend the service life of the existing pavement between 3 and 5 years. Depending on the maintenance planning of the facility and construction budget, it may be more advantageous to mill and replace the existing surface course in the areas where the existing pavement is to remain in place. This would provide a more consistent pavement throughout the entire facility after construction and would better match the areas of new construction. This would also prolong the service life of the existing pavements to better match the service life of the new pavements. The short section of existing asphaltic concrete just beyond the concrete pavement in the commercial lanes with moderate rutting should be full depth reconstructed, since it appears that the granular base does not have adequate thickness for the concentrated commercial traffic. If it chosen to repair the existing pavement distresses and surface seal the existing pavement, then it is suggested that another pavement condition survey be carried out within the next three to five years,

30 Project since on the distresses are moderate to severe. Additional discussion can be provided during detailed design based on an increased understanding of future places for the facility New Pavement Construction Based on provided historical traffic data, the proposed traffic volumes, estimated growth rates and the subsoil conditions encountered, conventional asphaltic (flexible) pavement designs are considered to be appropriate for most proposed paved areas. Based on the historical traffic data, it appears that approximately 1,170,000 passenger vehicles and 180,000 commercial vehicles travel northbound through the facility each year. Using this traffic data and applying a growth of 2.8 percent for passenger vehicles and 3.6 percent for commercial vehicles, the Equivalent Single Axle Load (ESAL) for a 20 year design life would be and 820,000 for the light duty section and 8.6 million for the heavy duty section. Based on the results of this investigation and experience, the following asphaltic pavement designs are recommended for both light duty and heavy duty areas: Pavement Layer Asphaltic Concrete Granular Base Course Granular Sub-Base Course Table 14 Recommended Pavement Structures Light Duty Traffic Areas Heavy Duty and Mixed Traffic Areas (Cars and Buses Only) (Commercial Truck Traffic) 50 mm SP 12.5, FC1, Surface Course 60 mm SP 19.0, Base Course 50 mm SP 12.5, FC1, Surface Course 90 mm SP 25.0, Base Course 200 mm OPSS Granular A 300 mm OPSS Granular A 375 mm OPSS Granular B 575 mm OPSS Granular B Asphalt materials and placement specifications should be in accordance with relevant Provincial standard specifications. The asphaltic cement should be PG due to the frequent stopping and slow traffic speeds through the facility. A functional design life of eight to ten years has been used to establish the flexible pavement recommendations. This represents the number of years to the first rehabilitation, assuming regular maintenance is carried out. If required, a more refined pavement structure design can be performed based on specific traffic data and design life requirements provided by the client. The long term performance of the pavement is highly dependent upon the subgrade support conditions. Stringent construction control procedures should be maintained to ensure uniform subgrade moisture and density conditions are achieved. In addition, the need for adequate drainage cannot be overemphasized. The finished pavement surface and underlying subgrade should be free of depressions and should be sloped to provide effective surface drainage toward catch basins. Surface water should not be allowed to pond adjacent to the outside edges of pavement areas. Subdrains can also be placed at catch basins and along curb lines to further improve sub-surface drainage.

31 Project As part of the subgrade preparation, proposed paved areas should be stripped of existing asphalt, topsoil and other objectionable materials. Fill required to raise the grades to design elevations should conform to backfill requirements outlined in previous sections of this report. The subgrade should be properly shaped, crowned then proof-rolled in the full time presence of a representative of this office. Soft or spongy subgrade areas should be sub-excavated and properly replaced with suitable approved backfill compacted to 98% SPMDD. Base and sub-base layers should be compacted to 100% of SPMDD. The most severe loading conditions on light-duty pavement areas and the subgrade may occur during construction. Consequently, special provisions such as restricted access lanes, half-loads during paving, etc., may be required, especially if construction is carried out during unfavourable weather. Rigid pavements are recommended in critical areas (typically where heavy vehicles move at low speeds, start and stop, or turn). Rigid pavements will perform better than a flexible section in these critical areas. The following pavement structure is recommended for the rigid pavement (concrete) areas: Pavement Layer Rigid Pavement Granular Base Course Table 15 Recommended Rigid Pavement Structure Material 205 mm of Reinforced Concrete 400 mm OPSS Granular A It would be prudent to provide the same subgrade level across adjacent rigid and flexible pavement sections and thus promote draining and prevent the need to construct frost tapers. The concrete should satisfy the requirements of CAN/CSA A 23.1 Class C-2 concrete with a minimum compressive strength of 32 MPa and should have a minimum flexural strength of 4.1 MPa. The base should consist of granular base material and be compacted to 100 percent of its standard Proctor maximum dry density. The pavement could be expected to perform better in the long term if the granular backfill against the foundation walls is drained by means of a perforated pipe subdrain in a surround of 19 millimetre clear stone, fully wrapped in geotextile, which leads by gravity drainage to a positive outlet as outlined above. It is recommended that SPL Consultants Limited be retained to review the final pavement structure designs and drainage plans prior to construction to ensure that they are consistent with the recommendations of this report Construction Considerations Rock Removal The bedrock encountered within the boreholes during the current investigation was quite variable ranging from fresh to weathered, intact to highly fractured, with vertical to near vertical fractures. Rock removal within the proposed Traffic, Commercial and Customs Building could require a variety to rock

32 Project removal techniques ranging from dozers equipped with rippers, hydraulic excavators with pneumatic hammers (hoe ramming) and controlled blasting. Material properties of the bedrock encountered during this investigation are discussed in Section of this report. The blasting should be controlled to limit the peak particle velocities at all adjacent structures or services such that blast induced damage will be avoided. This will require blast designs by a specialist in this field. A pre-blast survey should be carried out in general accordance with OPSS 120 for all of the surrounding structures, such as the nearby hotel, the Duty Free shop and the existing buildings at the facility. Selected existing interior and exterior cracks in the structures should be identified during the pre-blast survey and should be monitored for lateral or shear movements by means of pins, glass plate telltales and/or movement telltales. The contractor should be limited to only small controlled shots. The construction and blasting operations should be generally limited to the maximum peak particle velocities outlined in OPSS 120. These limits should be practical and achievable on this project. Should there be structures in the area sensitive to vibrations, such as the viewing tower about 500 m from the site or onsite security instruments, more stringent specifications should be developed by a vibration specialist. It is recommended that the monitoring of ground vibration intensities (peak ground vibrations and accelerations) from the blasting operations be carried out both in the ground adjacent to the closest structures and within the structures themselves Construction Dewatering The groundwater level at the site was found to be between elevation 78.5 and 75.0 m. Several heavily water stained fractures, some with soil infill were observed during the current investigation, and thus moderate to significant water flows through these fractures is anticipated. For excavations above the water table and slightly below (less than 0.5 m) the water table, it is likely that seepage into the excavations can be managed using properly filtered sumps, ditches, etc. For deeper excavations, additional or more complex dewatering may be required. SPL can provide additional guidance based on the size and depth of the excavation, if required during detailed design. A Ministry of Environment (MOE) Permit to Take Water (PTTW) may be required for deep excavations below the observed groundwater levels. This requirement should be reviewed during detailed design based on the actual excavation details Temporary Excavations All excavations should be carried out in accordance with the most recent Occupational Health and Safety Act (OHSA). Part III of Ontario Regulation 213/91 deals with excavations.

33 Project The soils within the expected excavation include both granular and fine grained fill, cobbles and boulder, possible rock fill and native silty clay. For preliminary planning purposes the existing fill can be classified as a Type 3 Soil above the groundwater table (or depth of watering). The native silty clay can be classified as a Type 3 Soil above the groundwater table (or depth of watering) and Type 4 soils below the groundwater table (or depth of watering). These classifications must be reviewed and confirmed by a qualified person during excavation. Excavations within Type 3 soil require side slopes with a minimum gradient of 1 horizontal to 1 vertical and excavations within Type 4 soil require side slopes of 3 horizontal to 1 vertical. Due to the limited space available a temporary shoring system will likely be required. Once the location of the building and the basement floor elevation is determined the need for vertical shoring should be reviewed. The type of shoring to be used depends on the permissible movement of the shoring. The design of any the shoring system must be carried out by a professional engineer and take into consideration the effect of the excavation upon the neighbouring buildings and structures. The contractor is typically responsible for the detailed design of temporary shoring. If required, SPL can provide additional guidance based on preliminary excavation plans, depths, etc. during the detailed design phase of the project Subgrade Preparation The geotechnical bearing resistances provided in Section assume that the foundation soils will not be disturbed by construction activities. Proper de watering and protection of the exposed subgrade will be important to the construction of the foundations. All excavated surfaces should be kept free of frost, water, etc. during the course of construction. All excavated surfaces should be inspected by a qualified geotechnical engineer who is familiar with the findings of this investigation and the design and construction of similar structures. The foundations soils (where present) at the site are expected to be sensitive to disturbance from ponded water and construction traffic if the subgrade for the foundations and basement floor slab is exposed for a prolonged duration and/or exposed to construction traffic then placement of a mud slab directly on the subgrade may be required to protect the subgrade from these elements. It is understood that the grade will be raised in the eastern part of the site where existing pavements exist. It is recommended that any existing asphaltic concrete pavement, such as portions of the existing southern parking lot be either pulverized and compacted or completely removed prior to the placement of any site fill. Topsoil, organics, deleterious materials and any other unsuitable materials should be removed prior to any placement of fill Winter Construction In the event of construction during freezing temperatures, the founding stratum for each structure should be protected from freezing by the use of loose straw, tarpaulins, propane heaters or other

34 Project suitable means. In this regard, the base of the excavations should be insulated from sub-zero temperatures immediately upon exposure and until such time the footings are protected with sufficient soil cover to prevent freezing at the founding level. 7. CLOSURE The Limitations of Report, as presented in Appendix IV, are an integral part of this report. Since this report was prepared during the preliminary design phase and many details of the project have not been determined, therefore it is recommended that SPL reviewed this report during the detailed design phase. We trust that the information contained in this report is satisfactory. Should you have any questions, please do not hesitate to contact this office. SPL CONSULTANTS LIMITED Bruce Goddard, P.Eng, P.E. Senior Geotechnical Engineer Chris Hendry, M.Eng., P.Eng. Senior Geotechnical Engineer

35 Project Drawings

36 Client: The Federal Bridge Corporation Ltd. Project#: DWG #: 1 Drawn: DW Approved: BG Date: October 2014 Scale: N. T. S. Size: Letter Rev: 0 Title: Project: Site Plan Geotechnical Investigation - CBSA Redevelopment of Thousand Island International Crossing