Geotechnical Investigation Proposed Richmond Home Hardware Addition 6379 Perth Street Richmond, Ontario

Transcription

1 Geotechnical Investigation Proposed Richmond Home Hardware Addition 6379 Perth Street Richmond, Ontario Houle Chevrier Engineering Ltd. 180 Wescar Lane Ottawa, Ontario K0A 1L0

2 Submitted to: Argue Construction Ltd. 5A Willowlea Road Ottawa, Ontario K0A 1L0 Geotechnical Investigation Proposed Richmond Home Hardware Addition 6379 Perth Street Richmond, Ontario January 6, 2015 Project: Houle Chevrier Engineering Ltd. 180 Wescar Lane Ottawa, Ontario K0A 1L0

3 TABLE OF CONTENTS 1.0 INTRODUCTION PROJECT AND SITE DESCRIPTION Project and Site Description and Review of Geology Maps SUBSURFACE INVESTIGATION SUBSURFACE CONDITIONS General Fill/Possible Fill Material Silty Clay / Clayey Silt / Silt and Clay Sandy Silt Glacial Till Inferred Bedrock Groundwater Levels Soil Chemistry Relating to Corrosion PROPOSED EXPANSION General Excavation Foundations Foundation Wall Backfill Concrete Slab on Grade Storage Building General Pier Foundation Grade Raise Restrictions Frost Protection of Foundation Seismic Site Classification and Liquefaction Potential ADDITIONAL CONSIDERATIONS Winter Construction Disposal of Excess Soil Effects of Construction Induced Vibration Design Review and Construction Observation...14 Report to: Argue Construction Ltd. Project: (January 6, 2015) ii

4 LIST OF FIGURES Figure 1: Key Plan Figure 3: Borehole Location Plan LIST OF APPENDICES Appendix A Appendix B Record of Borehole Sheets Soil Chemistry Relating to Corrosion Report to: Argue Construction Ltd. Project: (January 6, 2015) iii

5 1.0 INTRODUCTION This report presents the results of a geotechnical investigation carried out for the proposed commercial expansion of the Richmond Home Hardware located at 6379 Perth Street in the town of Richmond, Ontario (refer to Key Plan, Figure 1). The purpose of the investigation was to identify the general subsurface conditions at the site by means of a limited number of boreholes and, based on the factual information obtained, to provide engineering guidelines on the geotechnical design aspects of the project, including construction considerations, which could influence design decisions. This investigation was performed in accordance with our proposal dated November 19, PROJECT AND SITE DESCRIPTION 2.1 Project and Site Description and Review of Geology Maps It is understood that plans for the expansion of Richmond Home Hardware include the construction of a new one storey addition to the existing one storey building as well as the construction of a new one storey open aired storage building. The addition is anticipated to be 372 square metres (in plan) and of slab on grade construction (i.e. basementless). The new storage building is anticipated to be about 446 square metres (in plan) and gravel or asphalt surfaced. Currently the site is occupied by the existing hardware store, storage shed and stockpiles of construction materials. Based on our previous experience in the area as well as surficial geology maps, the site is likely underlain by marine deposits of clay and silt with a thickness ranging from 5 to metres. Bedrock geology maps of the Ottawa area indicate that the overburden is underlain by dolostone bedrock of the Oxford formation. 3.0 SUBSURFACE INVESTIGATION The field work for this investigation was carried out on December 4, During that time, four (4) boreholes were advanced at the site using a track mounted drill rig supplied and operated by Aardvark Drilling Inc. Details of the boreholes are provided below: Two (2) boreholes, numbered 141 and 142 were advanced to depths of about 6.1 metres below ground surface at the outside corners of the proposed addition. These boreholes were advanced for foundation design purposes. One (1) dynamic cone (CPT) was driven from the bottom of borehole 141 to practical refusal on inferred bedrock at a depth of about 7.0 metres below ground surface. The CPT was driven in order to assess the seismic Site Class for the subject property. Report to: Argue Construction Ltd. Project: (January 6, 2015) 1

6 Two (2) boreholes, numbered 143 and 144 were advanced to depths of 4.7 and 4.5 metres below ground surface, respectively, in the area of the proposed storage building. These boreholes were advanced for foundation design purposes. Standard penetration tests were carried out in the boreholes and samples of the soils encountered were recovered using a millimetre diameter split barrel sampler. In situ vane shear strength testing was carried out where possible in the clayey deposits to measure the undrained shear strength. The groundwater levels were observed in the open boreholes upon completion of the drilling work. The field work was supervised throughout by a member of our engineering staff who directed the drilling operations, logged the samples and carried out the insitu testing. Following the field work, the soil samples were returned to our laboratory for examination by a geotechnical engineer. Selected soil samples were tested for water content, grain size distribution and Atterberg limits. The locations and elevations of the boreholes were measured by Houle Chevrier Engineering Ltd. using our Trimble R8 GPS survey instrument. The elevations are referenced to Geodetic datum. Descriptions of the subsurface conditions logged in the boreholes are provided on the Record of Borehole sheets in Appendix A. The approximate locations of the boreholes are shown on the Borehole Location Plan, Figure 2. The results of the soil classification testing are provided on the Record of Borehole sheets and on Figures A1 and A2 in Appendix A. 4.0 SUBSURFACE CONDITIONS 4.1 General As previously indicated, the soil and groundwater conditions identified in the boreholes are given on the Record of Borehole sheets in Appendix A. The borehole logs indicate the subsurface conditions at the specific test locations only. Boundaries between zones on the logs are often not distinct, but rather are transitional and have been interpreted. The precision with which subsurface conditions are indicated depends on the method of drilling, the frequency and recovery of samples, the method of sampling, and the uniformity of the subsurface conditions. Subsurface conditions at other than the test locations may vary from the conditions encountered in the test holes. In addition to soil variability, fill of variable physical and chemical composition can be present over portions of the site or on adjacent properties. The groundwater conditions described in this report refer only to those observed at the place and time of observation noted in the report. These conditions may vary seasonally or as a consequence of construction activities in the area. Report to: Argue Construction Ltd. Project: (January 6, 2015) 2

7 The soil descriptions in this report are based on commonly accepted methods of classification and identification employed in geotechnical practice. Classification and identification of soil involves judgement and Houle Chevrier Engineering Ltd. does not guarantee descriptions as exact, but infers accuracy to the extent that is common in current geotechnical practice. The following presents an overview of the subsurface conditions encountered in the boreholes advanced during this investigation. 4.2 Fill/Possible Fill Material All of the boreholes encountered fill/possible fill material from ground surface. Table 4.11 below describes the fill material encountered during the current investigation. Table 4.1: Summary of Fill Material Encountered (Depth in Metres) Borehole Grey Crushed Sand and Gravel Brown, fine to medium grained sand, some silt and gravel Grey brown silty clay (possible fill) Standard penetration tests carried out in the possible silty clay fill materials gave N values of 5 and 9 blows per 0.3 metres of penetration, which reflects a stiff to very stiff consistency. The water content of samples of the fill/possible fill material ranges from about 3 to 41 percent. 4.3 Silty Clay / Clayey Silt / Silt and Clay A native deposit of silty clay/clayey silt/silt and clay (herein referred to as silty clay) was encountered below the fill/possible fill material at all of the borehole locations at depths ranging from about 0.6 to 1.5 metres. The upper portion of the silty clay can be described as grey brown weathered crust. Standard penetration tests carried out in the weathered crust gave N values of 1 to 8 blows per 0.3 metres of penetration, decreasing with depth. Attempts were undertaken to carry out in situ vane shear strength tests in the weathered crust at boreholes 14 2 and 144. During some of the tests, the torque measuring equipment reached its capacity Report to: Argue Construction Ltd. Project: (January 6, 2015) 3

8 without turning the vane, which indicates shear strength values in excess of 0 kilopascals and a very stiff consistency. At the location of borehole 144, at a depth of about 2.4 metres below ground surface, the insitu shear strength value was measured at about 73 kilopascals, which reflects a stiff consistency. The weathered silty clay crust has a thickness of about 1.5 to 2.4 metres at the borehole locations and extends to depths of about 2.9 to 3.6 metres below ground surface (elevations 91.5 to 92.0 metres, geodetic). Below the weathered crust in boreholes 141 and 143, the silty clay becomes grey in colour and contains silt seams and/or layers. The grey silty clay has a thickness of about 1.5 and 0.9 metres at boreholes 141 and 143, respectively, and extends to depths of about 4.6 and 3.8 metres below ground surface (elevations 90.4 and 91.1 metres, geodetic). Standard penetration tests carried out in the grey silty clay gave N values of 1 blow per 0.3 metres of penetration. In situ vane shear strength tests carried out in the grey silty clay give shear strength values ranging from about 8 to 48 kilopascals, which reflects a very soft to firm consistency. In our opinion, the very low shear strength measured (i.e. 8 kilopascals) from borehole 141 do not represent the actual soil consistency due to probable soil disturbance from water inflow into the augers through the silt seams in the silty clay. As such, during the fieldwork, a borehole was advanced adjacent to borehole 141 to confirm the soil at the locations of the in situ vane shear strength tests (i.e. Sample number A and B at 3.1 and 4.6 metres below ground surface, respectively) which confirmed the presence of silt seams and a sandy silt layer. A particle size distribution test and an Atterberg limit test were carried out on a sample of the weathered silty clay recovered from borehole 141 at about 1.8 metres below ground surface (elevation 93.1 metres, geodetic). The particle distribution test shows that the sample recovered from borehole 141 contains about 58 percent clay, about 39 percent silt size particles, and about 3 percent fine sand. The Atterberg limit test gave a liquid limit of 51 percent, a plastic limit of 21 percent and a corresponding plasticity index of 30. The testing indicates that the silt and clay is of high plasticity. The results of the testing are provided on Figures A1 and A2 in Appendix A. The water content measured in samples of the weathered grey brown silty clay crust collected from the boreholes range from about 38 to 65 percent and are generally at or below the measured liquid limit value. The water content from samples of the grey silty clay from borehole 141 are about 38 and 39 percent and are below the measured liquid limit value. Report to: Argue Construction Ltd. Project: (January 6, 2015) 4

9 4.4 Sandy Silt A deposit of sandy silt was encountered below the silty clay at all of the borehole locations at depths ranging from about 3.3 to 4.6 metres below ground surface (elevations 90.4 to 91.6 metres, geodetic). The sandy silt can generally be described as grey with variable amounts of clay. The sandy silt has a thickness ranging from about 0.5 to 1.5 metres. Standard penetration tests carried out in the sandy silt encountered in the boreholes gave N values ranging from 3 to 12 blows per 0.3 metres of penetration, which reflects a very loose to compact relative density. An Atterberg limit test was carried out on a sample of the grey sandy silt recovered from borehole 142 at a depth of about 4.1 metres below ground surface in order to determine the behaviour of the soil for liquefaction analysis. The Atterberg limit test gave a liquid limit of 18 percent, plastic limit of 17 percent and a corresponding plasticity index of 1 (see Figure A2). The water content of the sandy silt samples from boreholes 141, 142, and 144 range from about 16 to 28 percent. Borehole 144 was terminated within the sandy silt at a depth of about 4.5 metres below ground surface (elevation 90.3 metres, geodetic). 4.5 Glacial Till Glacial till was encountered below the sandy silt at boreholes 141 to 143, inclusive, at depths ranging from about 4.3 to 5.0 metres below ground surface (elevations 89.9 to 90.6 metres, geodetic). The glacial till is composed of grey silty sand with variable amounts of gravel. Cobbles and boulders should also be expected within the glacial till. Standard penetration tests carried out in the glacial till gave N values of 13 and 19 blows per 0.3 metres of penetration, which reflects a compact relative density. A dynamic cone penetration test was carried out in borehole 141 from 6.1 to 7.0 metres below ground surface. The dynamic cone penetration test carried out in the glacial till deposit gave penetration values between and 81 blows per 0.3 metres of penetration. The dynamic cone penetration test was terminated at practical refusal to driving of the cone on inferred bedrock at a penetration resistance of blows for no visible penetration. The water content from samples of the glacial till from the boreholes range from about to 11 percent. Borehole 142 was terminated within the glacial till at a depth of about 5.9 metres below ground surface (elevations 89.2 metres, geodetic). Report to: Argue Construction Ltd. Project: (January 6, 2015) 5

10 4.6 Inferred Bedrock Practical refusal to further advancement of the auger on the inferred bedrock surface occurred in boreholes 143 and 144 at depths of about 4.7 and 4.5 metres below ground surface (elevations 90.2 and 90.3 metres, geodetic), respectively. Practical refusal to further advancement of the dynamic cone occurred in borehole 141 at 7.01 metres below ground surface (elevation 87.9 metres, geodetic) on the inferred bedrock surface. It should be noted that practical refusal of the auger and dynamic cone can sometimes occur on boulders and may not necessarily be representative of the upper surface of the bedrock. 4.7 Groundwater Levels The groundwater levels observed in the open boreholes during the relatively short period they were left open are summarized in Table 4.2: Table 4.2 Groundwater Depth and Elevation (December 4, 2014) Borehole Groundwater Depth Below Existing Ground Surface (metres) Groundwater Elevation (metres, geodetic datum) The groundwater levels may be higher during wet periods of the year such as the early spring or following periods of precipitation. 4.8 Soil Chemistry Relating to Corrosion The results of chemical testing on a soil sample recovered from borehole 142 at a depth between 1.5 and 2.1 metres below ground surface are provided in Appendix B and are summarized in Table 4.3 below: Report to: Argue Construction Ltd. Project: (January 6, 2015) 6

11 Table 4.3: Summary of Corrosion Testing Soil Parameter Borehole 142 SA3 (1.5m 2.1m) Chloride Content (µg/g dry) 30 Conductivity (microsiemens/cm) 237 ph 7.15 Sulphate Content (µg/g dry) PROPOSED COMMERCIAL EXPANSION 5.1 General The information in the following sections is provided for the guidance of the design engineers and Argue Construction and is intended for the design of this project only. Other contractors bidding on or undertaking the works should examine the factual results of the investigation, satisfy themselves as to the adequacy of the information for construction, and make their own interpretation of the factual data as it affects their construction techniques, schedule, safety and equipment capabilities. The professional services retained for this project include only the geotechnical aspects of the subsurface conditions at this site. The presence or implications of possible surface and/or subsurface contamination resulting from previous uses or activities of this site or adjacent properties, and/or resulting from the introduction onto the site from materials from off site sources are outside the terms of reference for this report. 5.2 Liquefaction Assessment During a significant seismic event, vibrations can sometimes cause the pore water pressure to increase within the soil mass and in severe cases, can create a condition known as seismic liquefaction. The excess pore water pressure created reduces the effective stress between the soil particles as well as the soil s resistance to shearing (frictional resistance). A temporary reduction in the shear strength of the soil may cause, among other issues, lateral movements of gently sloping ground and a reduction in bearing capacity, and settlement of structures. Soils which are more prone to experiencing seismic liquefaction include: Coarse grained soils (i.e., more probable for sands than for silts); Soils having a loose state of packing; and, Soils located below the groundwater level. Report to: Argue Construction Ltd. Project: (January 6, 2015) 7

12 An assessment of the liquefaction potential of the sandy silt deposit was carried out using the Seed and Idriss (1971) simplified procedure based on the cyclic stress ratio. The results of the assessment suggest that the sandy silt soils could be classified as potentially liquefiable during a significant seismic event. The amount of settlement is highly variable since it is dependent on the magnitude of the earthquake, the thickness of the sandy silt deposit and its liquefaction potential. Based on the thickness of the sandy silt deposit, the anticipated settlement of the liquefiable native sands could be up to about millimetres under a significant seismic event. It is suggested that the building design take this into account or alternatively, a seismic cone penetration test could be carried out at the site to better assess the potential for seismic liquefaction. It is considered that the above magnitudes of settlement could be acceptable, and therefore typical strip, pad and pier footings could be used at this site. If the amount of settlement is not acceptable, alternate foundation designs could be considered, such as densifying the liquefiable soils (in order to reduce their liquefaction potential and associated settlements) or found the structure on deep foundations. Further guidelines on densification or deep foundations could be provided upon request. 5.3 Excavation The excavation for the proposed building addition and the new storage building will be carried out through fill material and native deposits of silty clay. The sides of the excavation should be sloped in accordance with the requirements in Ontario Regulation 213/91 under the Occupational Health and Safety Act. According to the act, soils at this site can be classified as Type 3. That is, open cut excavations within overburden deposits should be carried out with side slopes of 1 horizontal to 1 vertical, or flatter. Disturbance to the silty clay subgrade can occur during excavation due to flow of soil between the teeth on a standard bucket. To reduce disturbance of the subgrade soil, the final trimming to the design elevation should be done using a bucket with a flat blade. It is our experience that the upper part of the silty clay weathered crust may be impacted by past frost action. During stripping of the site, there is potential for the upper part of the weathered silty clay to peel upwards and become disturbed. Where this occurs within the building area, the disturbed soil should be removed and replaced with compacted OPSS Granular B Type II Excavation Next to Existing Building Foundations To prevent undermining of the existing building foundations, it is recommended that the bottom of the excavation for the proposed addition be located beyond a line extending down and out from the bottom edge of the existing and adjacent building foundations at 1 horizontal to 1 vertical, or flatter. If excavation is required within this zone, underpinning or temporary support Report to: Argue Construction Ltd. Project: (January 6, 2015) 8

13 of the existing and adjacent foundations may be required. Details for underpinning and/or support of foundations could be provided upon request. The underside of footing level should match the existing underside of footing level where the new foundation walls abut the existing foundation walls Groundwater Pumping Groundwater inflow from the overburden deposits should be relatively small and controlled by pumping from filtered sumps within the excavation. It is not expected that short term pumping during excavation will have a significant effect on nearby structures and services. It should be noted that the groundwater conditions were only observed for the relatively short time that the boreholes were left open upon completion of drilling. The observations do not represent stabilized groundwater conditions. 5.4 Foundations Based on the boreholes advanced during the present investigation, the subgrade conditions across the site consist of fill material followed by native deposits of silty clay, sandy silt and glacial till. The proposed structures could be founded on conventional spread footings bearing on or within the native, undisturbed deposits of weathered silty clay crust or on a pad of compacted granular material (engineered fill) over native, undisturbed soil deposits. Where wet conditions are encountered, the engineered fill should be underlain by a woven geotextile meeting OPSS 1860 Class 2 requirements. The engineered fill, where required, should consist of granular material meeting Ontario Provincial Standard Specifications (OPSS) requirements for Granular B Type II. OPSS documents allow recycled asphaltic concrete and concrete to be used in Granular B Type II materials. Since the source of recycled material cannot be determined, it is suggested that any granular materials used beneath the proposed building be composed of virgin material only for environmental reasons. The OPSS Granular B Type II should be compacted in maximum 200 millimetre thick lifts to at least 95 percent of the standard Proctor dry density value. To provide adequate spread of load below the footings, the material should extend at least 0.5 metres horizontally beyond the edge of the footings and down and out from this point at 1 horizontal to 1 vertical, or flatter. The allowable bearing pressures for spread footing foundations at this site are based on the necessity to limit the stress increase on the softer, compressible grey silty clay to an acceptable level such that foundation settlements will not be excessive. Four important parameters in calculating the stress increase on the grey silty clay beneath the weathered crust are: The thickness of the weathered crust beneath the base of the foundation, The size and type (i.e. pad, strip or pier) of the foundation, Report to: Argue Construction Ltd. Project: (January 6, 2015) 9

14 The amount of surcharge (fill, etc.) in the vicinity of the foundation, and The magnitude and type of ground floor loading. For design purposes, the following bearing pressures should be used for footings bearing on or within native undisturbed deposits of silty clay. Table 5.1 Allowable Bearing Pressure Store Addition Type of Footing Maximum Depth of Footing (metres) Maximum Size of Footing (metres) Factored Net Geotechnical Resistance at Serviceability Limit State (SLS) (kilopascals) Factored Net Geotechnical Reaction at Ultimate Limit State (ULS) (kilopascals) Strip Pad x Notes: 1. The bearing pressures assume that the proposed grades will be within +/ 1 millimetres of existing site elevations. 2. The sustained slabongrade load of the addition and ground load in the storage building is assumed to be 5 kilopascals. There are many other possible combinations of founding depths, footing sizes and thickness of grade raise fills which might be suitable for this project on this site. Furthermore, the floor/ground loading could also affect the design of the foundations. All other alternatives must be checked by the geotechnical engineer to ensure that overstressing of the softer silty clay/clayey silt soil does not occur as this could result in excessive settlement of the building addition and/or the storage building. Assuming that the footing areas are cleaned of loose or disturbed soil, the total and differential settlement of the footings should be less than 25 and 20 millimetres, respectively. The settlement of the addition will be differential relative to the existing structure; therefore, it is recommended that the addition be structurally separated from the existing building. 5.5 Foundation Wall Backfill The fill material and native deposits at this site are frost susceptible and should not be used as backfill against foundations, piers, etc. The backfill material should consist of imported sand or sand and gravel meeting OPSS requirements for Granular B Type I or II. Where the backfill will ultimately support areas of hard surfacing (pavement, sidewalks or other similar surfaces), the backfill should be placed in maximum 200 millimetre thick lifts and should be compacted to at least 95 percent of the standard Proctor maximum dry density value using suitable vibratory Report to: Argue Construction Ltd. Project: (January 6, 2015)

15 compaction equipment. Light hand operated compaction equipment should be used next to the foundation walls to avoid excessive compaction induced stress on the foundation walls. Where future landscaped areas will exist next to the proposed structures and if some settlement of the backfill is acceptable, the backfill could be compacted to at least 90 percent of the standard Proctor maximum dry density value. Where areas of hard surfacing (concrete, sidewalk, pavement, etc.) abut the proposed buildings, a gradual transition should be provided between those areas of hard surfacing underlain by nonfrost susceptible granular wall backfill and those areas underlain by existing frost susceptible native materials to reduce the effects of differential frost heaving. It is suggested that granular frost tapers be constructed from the underside of footing grade to the underside of the granular base/subbase material for the hard surfaced areas. The frost tapers should be sloped at 3 horizontal to 1 vertical, or flatter. Perimeter foundation drainage is not considered necessary for a slab on grade structure at this site, provided that the floor slab level is above the finished exterior ground surface level. 5.6 Concrete Slab on Grade (Heated Areas Only) To provide predictable settlement performance of the concrete slab on grade, all fill and possible fill material should be removed from below the slab areas. Following removal of these materials, and prior to placement of any grade raise fill material, the subgrade surface should be proof rolled with a large ( tonne minimum) vibratory drum roller under the supervision of a geotechnical engineer. Any soft areas determined from the proof rolling should be subexcavated and replaced with suitable granular material (i.e., OPSS Granular B Type I or II). The grade within the proposed addition could then be raised, where necessary, with imported granular material conforming to OPSS requirements for Granular B Type I or II. The granular base for the proposed slab on grade should consist of at least 1 millimetres of OPSS Granular A. City of Ottawa documents allow recycled asphaltic concrete and concrete to be used in Granular A and Granular B Type I materials. Since the source of recycled material cannot be determined, it is suggested that any granular materials used beneath the floor slabs be composed of virgin material only, for environmental purposes. The Granular A and Granular B Type I or II should be compacted in maximum 200 millimetre thick lifts to at least 95 percent of the standard Proctor dry density value using suitable vibratory equipment. Report to: Argue Construction Ltd. Project: (January 6, 2015) 11

16 If any areas of the proposed building addition are to remain unheated during the winter period, thermal protection of the slab on grade may be required. Further details on the insulation requirements could be provided, if necessary. The floor slab should be wet cured to minimize shrinkage cracking and slab curling. The slab should be saw cut to about 1/3 the thickness of the slab as soon as curing of the concrete permits, in order to minimize shrinkage cracks. 5.7 Storage Building General If strip footings are anticipated for the storage building at this site, the recommendations provided in Section to Section apply for the construction of the storage building as well. If a pier foundation is anticipated, the following design and construction guidelines are provided Pier Foundation For piers founded at 1.8 metres below ground surface, the subgrade soil at the storage building location consists mainly of grey brown silty clay (weathered crust). Based on the subsurface conditions which were encountered in the boreholes, the structure could be supported on piers bearing on or within native, undisturbed deposits of silty clay and sized using: geotechnical reaction at Serviceability Limit State (SLS) of 90 kilopascals; factored geotechnical resistance at Ultimate Limit State (ULS) of 1 kilopascals. If the piers are supported on conventional concrete pad footings, the foundation bearing values and sizes given in Table 5.1 may be used. Relatively small diameter pier foundations are more susceptible to a punching type of failure than larger pad footings. As such, consideration should be given to supporting the concrete piers on conventional concrete pad footings. The larger pad footings will also allow for greater structural capacity and in turn, less piers to support the structure. The post construction total and differential settlement of the piers should be less than 25 millimetres and 20 millimetres, respectively, provided that all loose and disturbed soil has been removed from the bottom of the excavation prior to pouring the concrete piers. The piers at this site should be provided with a minimum 1.8 metres of earth cover for frost protection purposes. Report to: Argue Construction Ltd. Project: (January 6, 2015) 12

17 The soil on this site was found to be frost susceptible. It is therefore recommended that in order to prevent adfreeze of the soil to the concrete and possible frost jacking, the concrete for the piers should be placed within formwork (i.e. sonotubes or a steel form). The unsupported portion of the formwork should be braced to reduce shifting during concrete and backfill placement. The concrete piers should be backfilled with free draining, nonfrost susceptible soil such as OPSS Granular A or Granular B Type II, and placed in maximum 200 millimetre thick lifts and compacted to at least 95 percent of the standard Proctor dry density value using suitable vibratory compaction equipment. Alternatively, if the piers are augered and cast in place, or backfilled with the native soil, the piers should be provided with a bond break such as 2 layers of 6 MIL polyethylene sheeting. 5.8 Grade Raise Restrictions The firm grey silty clay deposit found below the weathered crust has a limited capacity to support loads from footings and grade raise fill material. The geotechnical guidelines below assume that the finished grade elevation at the site will be about +/ 1 millimetres of the original ground surface on site (i.e., approximately 95.0 metres, geodetic) as found at the locations of boreholes 141 and 142. If consideration is being given to raising the grade at the site, the bearing pressures outlined in Sections 5.3 and 5.6 will need to be reduced accordingly. 5.9 Frost Protection of Foundations All exterior footings and footings in heated portions of the proposed buildings should be provided with at least 1.5 metres of earth cover for frost protection purposes. Isolated, unheated exterior footings and/or piers adjacent to surfaces which are cleaned of snow cover during the winter months should be provided with a minimum of 1.8 metres of earth cover. Alternatively, the required frost protection could be provided by means of a combination of earth cover and extruded polystyrene insulation. An insulation detail could be provided upon request. 5. Seismic Site Classification and Liquefaction Potential The subsurface conditions at the site are composed of fill over native deposits of silty clay, sandy silt, and glacial till. Bedrock was inferred in boreholes 141, 143, and 144 at depths ranging from about 4.5 to 7.0 metres below ground surface. Based on the soil and groundwater conditions encountered together with the results of the in situ testing, there is a potential for liquefaction of the sandy silt layer during a significant seismic event. The amount of settlement of the liquefiable soils could be up to millimetres. Based on the results of this investigation, Site Class F should be used for the seismic design of the addition and storage shed if the footings are constructed on the native overburden deposits or on a pad of engineered fill above the native deposits. The potential for seismic liquefaction of the soils at this site was made solely on the results of five (5) standard penetration tests. The Report to: Argue Construction Ltd. Project: (January 6, 2015) 13

18 results of standard penetration tests in sandy soils below the groundwater can be influenced by soil disturbance caused by drilling techniques/methodology. To further assess the potential for seismic liquefaction of these soils, a seismic cone penetration test could be carried out. The results of this test could change the Site Class and liquefaction potential. 6.0 ADDITIONAL CONSIDERATIONS 6.1 Winter Construction In the event that construction is required during freezing temperatures, the soil below the footings should be protected immediately from freezing using straw, propane heaters and insulated tarpaulins, or other suitable means. Any excavations should be opened for as short a time as practicable and the excavations should be carried out only in lengths which allow all of the construction operations, including backfilling, to be fully completed in one working day. The materials on the sides of the excavations should not be allowed to freeze. In addition, the backfill should be excavated, stored and replaced without being disturbed by frost or contaminated by snow or ice. 6.2 Disposal of Excess Soil It is noted that the professional services retained for this project include only the geotechnical aspects of the subsurface conditions at this site. The presence or implications of possible surface and/or subsurface contamination, including naturally occurring sources of contamination, are outside the terms of reference for this report. This report does not constitute a contaminated material management plan or an excess soil management plan. 6.3 Effects of Construction Induced Vibration Some of the construction operations (such as granular material compaction, excavation, etc.) will cause ground vibration on and off of the site. The vibrations will attenuate with distance from the source, but may be felt at nearby structures. The magnitude of the vibrations will be much less than that required to cause damage to the nearby structures or services in good condition. 6.4 Design Review and Construction Observation The details for the proposed construction were not available to us at the time of preparation of this report. It is recommended that the final design drawings be reviewed by the geotechnical engineer as the design progresses to ensure that the guidelines provided in this report have been interpreted as intended. The engagement of the services of the geotechnical consultant during construction is recommended to confirm that the subsurface conditions throughout the proposed excavations do not materially differ from those given in the report and that the construction activities do not Report to: Argue Construction Ltd. Project: (January 6, 2015) 14

19 adversely affect the intent of the design. The subgrade surfaces for the proposed storage building and store addition should be inspected by experienced geotechnical personnel to ensure that suitable materials have been reached and properly prepared. The placing and compaction of earth fill and imported granular materials should be inspected to ensure that the materials used conform to the grading and compaction specifications. We trust this report provides sufficient information for your present purposes. If you have any questions concerning this report, please do not hesitate to contact our office. 06 Jan 2015 Luc Bouchard, P.Eng. 06 Jan 2015 Craig Houle, M.Eng., P.Eng. Principal Report to: Argue Construction Ltd. Project: (January 6, 2015) 15

20 SITE LOCATION Project 6379 PERTH STREET, RICHMOND, ON GEOTECHNICAL INVESTIVATION Drawing KEY PLAN Drawn By P.C. Date December 2014 Project No. Revision No FIGURE 1 0

21 PERTH STREET LEGEND BH BOREHOLE LOCATION IN PLAN (current investigation by Houle Chevrier Engineering Ltd.) PERTH STREET BENCHMARK NAIL IN UTILITY POLE ELEVATION METRES KEY PLAN (NOT TO SCALE) BH PROPOSED NEW ONE STOREY ADDITION 372 m² EXISTING ONE STOREY BUILDING 560 m² BH PROPOSED NEW ONE STOREY OPEN AIRED STORAGE BLDG m² BH BH EXISTING CATCH BASIN ELEVATION METRES Scale 1: m Houle Chevrier Engineering 180 Wescar Lane Ottawa ON Tel: (613) info@hceng.ca Client Location Drwn by PC Date Argue Construction Ltd. Chkd by Rev. Project 6379 PERTH STREET, RICHMOND, ON LB December 15, BOREHOLE LOCATION PLAN 0 FIGURE 2

22 APPENDIX A Record of Borehole Sheets List of Abbreviations and Terminology Figure A1 and A2 Report to: Argue Construction Ltd. Project: (January 6, 2015)

23 LIST OF ABBREVIATIONS AND TERMINOLOGY SAMPLE TYPES AS auger sample CA casing sample CS chunk sample DO drive open MS manual sample RC rock core ST slotted tube TO thinwalled open Shelby tube TP thinwalled piston Shelby tube WS wash sample PENETRATION RESISTANCE Standard Penetration Resistance, N The number of blows by a 63.5 kg hammer dropped 760 millimetre required to drive a mm drive open sampler for a distance of 300 mm. For split spoon samples where less than 300 mm of penetration was achieved, the number of blows is reported over the sampler penetration in mm. Dynamic Penetration Resistance The number of blows by a 63.5 kg hammer dropped 760 mm to drive a mm diameter, 60 o cone attached to A size drill rods for a distance of 300 mm. WH WR PH PM Sampler advanced by static weight of hammer and drill rods. Sampler advanced by static weight of drill rods. Sampler advanced by hydraulic pressure from drill rig. Sampler advanced by manual pressure. SOIL DESCRIPTIONS Relative Density N Value Very Loose 0 to 4 Loose 4 to Compact to 30 Dense 30 to Very Dense over Consistency Undrained Shear Strength (kpa) Very soft 0 to 12 Soft 12 to 25 Firm 25 to Stiff to 0 Very Stiff over 0 LIST OF COMMON SYMBOLS c u undrained shear strength e void ratio C c compression index c v coefficient of consolidation k coefficient of permeability I p plasticity index n porosity u pore pressure w moisture content w L liquid limit w P plastic limit φ 1 effective angle of friction γ unit weight of soil γ 1 unit weight of submerged soil σ normal stress SOIL TESTS C consolidation test H hydrometer analysis M sieve analysis MH sieve and hydrometer analysis U unconfined compression test Q undrained triaxial test V field vane, undisturbed and remoulded shear strength Houle Chevrier Engineering Ltd.

24 PROJECT: LOCATION: See Borehole Location Plan, Figure 2 BORING DATE: December 4, 2014 RECORD OF BOREHOLE 141 SHEET 1 OF 1 DATUM: Geodetic SPT HAMMER: 63.5 kg; drop 0.76 m DEPTH SCALE METRES BORING METHOD SOIL PROFILE DESCRIPTION STRATA PLOT ELEV. DEPTH (m) SAMPLES NUMBER TYPE BLOWS/0.3m DYNAMIC PENETRATION RESISTANCE, BLOWS/0.3m HYDRAULIC CONDUCTIVITY, k, cm/s SHEAR STRENGTH nat. V Q WATER CONTENT, PERCENT Cu, kpa rem. V U W Wp Wl ADDITIONAL LAB. TESTING PIEZOMETER OR STANDPIPE INSTALLATION 0 1 Ground Surface Grey, crushed sand and gravel, trace silt (FILL) Brown, fine to medium grained sand, some silt and gravel, trace clay, possible cobbles (FILL) Grey brown silty clay, trace sand and gravel (POSSIBLE FILL) C.S. C.S. 9 Borehole backfilled with auger cuttings 2 Very stiff to stiff, grey brown SILT AND CLAY (WEATHERED CRUST) MH Power Auger 200mm Diameter Hollow Stem Auger Soft to firm, grey CLAYEY SILT, some silt seams/layers A BOREHOLE RECORD 2012 WITH LAB WC BOREHOLE LOGS DECEMBER GPJ DEPTH SCALE 1 to 40 Very loose, grey SANDY SILT, trace clay Very loose, grey SANDY SILT Compact to dense, grey silty sand, trace to some gravel, possible cobbles and boulders (TILL) Start of CPT test End of Borehole CPT refusal on inferred bedrock B Groundwater observed at 4.35 metres below ground surface after completion of drilling. LOGGED: A.N. CHECKED: L.B.

25 PROJECT: LOCATION: See Borehole Location Plan, Figure 2 BORING DATE: December 4, 2014 RECORD OF BOREHOLE 142 SHEET 1 OF 1 DATUM: Geodetic SPT HAMMER: 63.5 kg; drop 0.76 m DEPTH SCALE METRES BORING METHOD SOIL PROFILE DESCRIPTION STRATA PLOT ELEV. DEPTH (m) SAMPLES NUMBER TYPE BLOWS/0.3m DYNAMIC PENETRATION RESISTANCE, BLOWS/0.3m HYDRAULIC CONDUCTIVITY, k, cm/s SHEAR STRENGTH nat. V Q WATER CONTENT, PERCENT Cu, kpa rem. V U W Wp Wl ADDITIONAL LAB. TESTING PIEZOMETER OR STANDPIPE INSTALLATION 0 Ground Surface Grey, crushed sand and gravel, trace silt (FILL) Brown, fine to medium grained sand, some silt and gravel (FILL) C.S. Borehole backfilled with auger cuttings 1 Grey brown silty clay (POSSIBLE FILL) Very stiff to stiff, grey brown CLAYEY SILT (WEATHERED CRUST) Power Auger 200mm Diameter Hollow Stem Auger Loose to compact, grey SANDY SILT >> >> Groundwater observed at 1.34 metres below ground surface after completion of drilling BOREHOLE RECORD 2012 WITH LAB WC BOREHOLE LOGS DECEMBER GPJ DEPTH SCALE 1 to 40 Compact, grey silty sand, some gravel, possible cobbles and boulders (TILL) End of Borehole LOGGED: A.N. CHECKED: L.B.

26 PROJECT: LOCATION: See Borehole Location Plan, Figure 2 BORING DATE: December 4, 2014 RECORD OF BOREHOLE 143 SHEET 1 OF 1 DATUM: Geodetic SPT HAMMER: 63.5 kg; drop 0.76 m DEPTH SCALE METRES BORING METHOD SOIL PROFILE DESCRIPTION STRATA PLOT ELEV. DEPTH (m) SAMPLES NUMBER TYPE BLOWS/0.3m DYNAMIC PENETRATION RESISTANCE, BLOWS/0.3m HYDRAULIC CONDUCTIVITY, k, cm/s SHEAR STRENGTH nat. V Q WATER CONTENT, PERCENT Cu, kpa rem. V U W Wp Wl ADDITIONAL LAB. TESTING PIEZOMETER OR STANDPIPE INSTALLATION 0 Ground Surface Grey, crushed sand and gravel, trace silt and cobbles (FILL) Brown, fine to medium grained sand, some silt and gravel (FILL) Very stiff to stiff, grey brown SILTY CLAY (WEATHERED CRUST) A.S. C.S. Borehole backfilled with auger cuttings Power Auger 200mm Diameter Hollow Stem Auger Stiff to firm, grey SILTY CLAY Groundwater observed at 4.54 metres below ground surface after completion of drilling. BOREHOLE RECORD 2012 WITH LAB WC BOREHOLE LOGS DECEMBER GPJ DEPTH SCALE 1 to 40 Loose, grey SANDY SILT, trace clay Grey silty sand, trace to some gravel (TILL) End of Borehole Auger refusal on inferred bedrock LOGGED: A.N. CHECKED: L.B.

27 PROJECT: LOCATION: See Borehole Location Plan, Figure 2 BORING DATE: December 4, 2014 RECORD OF BOREHOLE 144 SHEET 1 OF 1 DATUM: Geodetic SPT HAMMER: 63.5 kg; drop 0.76 m DEPTH SCALE METRES BORING METHOD SOIL PROFILE DESCRIPTION STRATA PLOT ELEV. DEPTH (m) SAMPLES NUMBER TYPE BLOWS/0.3m DYNAMIC PENETRATION RESISTANCE, BLOWS/0.3m HYDRAULIC CONDUCTIVITY, k, cm/s SHEAR STRENGTH nat. V Q WATER CONTENT, PERCENT Cu, kpa rem. V U W Wp Wl ADDITIONAL LAB. TESTING PIEZOMETER OR STANDPIPE INSTALLATION 0 1 Ground Surface Grey, crushed sand and gravel, trace silt (FILL) Grey brown silty clay (FILL) A geotextile overlying a white perforated drainage pipe was encountered in the fill material Very stiff to stiff, grey brown SILTY CLAY (WEATHERED CRUST) A.S. C.S. Borehole backfilled with auger cuttings Power Auger 200mm Diameter Hollow Stem Auger Loose, grey SANDY SILT, trace clay >> Groundwater observed at 2.0 metres below ground surface after completion of drilling BOREHOLE RECORD 2012 WITH LAB WC BOREHOLE LOGS DECEMBER GPJ DEPTH SCALE 1 to 40 End of Borehole Auger refusal on inferred bedrock LOGGED: A.N. CHECKED: L.B.

28 GRAIN SIZE DISTRIBUTION FIGURE A1 Sieve Size, mm % Passing SOILS GRAIN SIZE GRAPH UNIFIED BOREHOLE LOGS DECEMBER GPJ HOULE CHEVRIER FEB GDT COBBLES Grain Size, mm COARSE FINE COARSE MEDIUM FINE GRAVEL SAND Legend Borehole Sample SILT AND CLAY Depth (m) Date: December 2014 Project: 14564

29 PLASTICITY CHART FIGURE A2 60 Group Symbol LOW "U" LINE HIGH "A" LINE CL = Lean Clay ML = Silt CH = Fat Clay MH = Elastic Silt CL ML = Silty Clay OL (Above "A" Line) = Organic Clay OL (Below "A" Line) = Organic Silt OH (Above "A" Line) = Organic Clay OH (Below "A" Line) = Organic Silt 40 Plasticity Index, PI 30 CH or OH 20 CL or OL MH or OH HCE ATTERBERG LIMITS BOREHOLE LOGS DECEMBER GPJ HOULE CHEVRIER FEB GDT CL ML ML or OL Liquid Limit, % Legend Borehole Sample Depth (m) LL % PL % PI % Date: December 2014 Project: 14564

30 APPENDIX B Soil Chemistry Relating to Corrosion Paracel Laboratories Report No Report to: Argue Construction Ltd. Project: (January 6, 2015)

31 Certificate of Analysis Houle Chevrier 180 Wescar Lane Ottawa, ON K0A1L0 Attn: Luc Bouchard Phone: (613) Fax: (613) Client PO: Project: Custody: 3647 Report Date: 11Dec2014 Order Date: 8Dec2014 This Certificate of Analysis contains analytical data applicable to the following samples as submitted: Paracel ID Client ID BH142 SA3 Order #: Approved By: Mark Foto, M.Sc. For Dale Robertson, BSc Laboratory Director Any use of these results implies your agreement that our total liabilty in connection with this work, however arising shall be limited to the amount paid by you for this work, and that our employees or agents shall not under circumstances be liable to you in connection with this work Page 1 of 7

32 Certificate of Analysis Client: Houle Chevrier Client PO: Project Description: Analysis Summary Table Order #: Report Date: 11Dec2014 Order Date:8Dec2014 Analysis Method Reference/Description Extraction Date Analysis Date Anions EPA IC, water extraction Dec14 Dec14 Conductivity MOE E3138 C, water ext Dec14 Dec14 ph EPA 1.1 ph 25 C, CaCl buffered ext. 9Dec14 Dec14 Solids, % Gravimetric, calculation 9Dec14 9Dec14 Page 2 of 7

33 Certificate of Analysis Order #: Report Date: 11Dec2014 Client: Houle Chevrier Order Date:8Dec2014 Client PO: Project Description: Client ID: BH142 SA3 Sample Date: 04Dec14 Sample ID: MDL/Units Soil Physical Characteristics % Solids 0.1 % by Wt General Inorganics Conductivity 5 us/cm 237 ph 0.05 ph Units 7.15 Anions Chloride 5 ug/g dry 30 Sulphate 5 ug/g dry 48 Page 3 of 7

34 Order #: Certificate of Analysis Client: Houle Chevrier Client PO: Project Description: Method Quality Control: Blank Analyte Result Reporting Limit Units Source Result %REC %REC Limit Report Date: 11Dec2014 Order Date:8Dec2014 RPD RPD Limit Notes Anions Chloride ND 5 ug/g Sulphate ND 5 ug/g General Inorganics Conductivity ND 5 us/cm Page 4 of 7

35 Certificate of Analysis Client: Houle Chevrier Client PO: Project Description: Method Quality Control: Duplicate Analyte Anions Result Reporting Limit Units Source Result Chloride ug/g dry Sulphate.2 5 ug/g dry General Inorganics Conductivity us/cm ph ph Units Physical Characteristics % Solids % by Wt %REC %REC Limit Order #: Report Date: 11Dec2014 Order Date:8Dec2014 RPD RPD Limit Notes Page 5 of 7

36 Certificate of Analysis Client: Houle Chevrier Client PO: Project Description: Method Quality Control: Spike Analyte Anions Result Reporting Limit Units Source Result %REC %REC Limit Chloride 9.1 mg/l Sulphate.6 mg/l Order #: Report Date: 11Dec2014 Order Date:8Dec2014 RPD RPD Limit Notes Page 6 of 7

37 Certificate of Analysis Client: Houle Chevrier Client PO: Project Description: Order #: Report Date: 11Dec2014 Order Date:8Dec2014 Qualifier Notes : None Sample Data Revisions None Work Order Revisions / Comments : None Other Report Notes : n/a: not applicable ND: Not Detected MDL: Method Detection Limit Source Result: Data used as source for matrix and duplicate samples %REC: Percent recovery. RPD: Relative percent difference. Soil results are reported on a dry weight basis when the units are denoted with 'dry'. Where %Solids is reported, moisture loss includes the loss of volatile hydrocarbons. Page 7 of 7

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