Subsurface Investigation and Geotechnical Engineering Report Proposed Volvo Dealership 1022 Hingham Street Rockland, Massachusetts

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1 HML ASSOCIATES Geotechnical and Civil Engineers March 31, Rockwood Road Hingham, MA 43 (Phone/Fax) Mr. Joe Rose Prime Motor Group 42 Providence Highway Westwood, MA 9 RE: Subsurface Investigation and Geotechnical Engineering Report Proposed Volvo Dealership 122 Hingham Street Rockland, Massachusetts Dear Mr. Rose: This letter report summarizes the results of our subsurface exploration and provides recommendations for foundation design and construction and site work for the proposed Volvo Dealership to be located at 122 Hingham Street in Rockland Massachusetts. (See Figure 1) A Site Plan/Boring Location Plan is included as Figure 3. Site photograph are included in Appendix 1. EXISTING SITE CONDITIONS/PROPOSED CONSTRUCTION The site is located on the north side of Hingham Street (Route 228) and to the east of Commerce Street in Rockland, Massachusetts. The site covers about 8.2 acres and is occupied by a recently constructed Hyundai dealership located in the southwest corner of the site adjacent to Hingham Street. The remainder of the site is paved and is used to store vehicle for sale as well as customer and employee parking, except for an unpaved area in the southeast corner where the proposed Volvo dealership will be located. Existing grades in the vicinity of the proposed dealership are between 146 and 147. feet as shown on the Existing Conditions Plan provided to HML Associates by Kelly Engineering Group. (Figure 2) The Existing Conditions Plan also shows drainage structures and drain lines within the limits of the proposed building. It is our undersigning that the proposed building will have a 24, sf footprint, will be slab on grade construction with a finished floor of el feet. Exterior grades will vary from on the west and south side to feet on the north and east sides. The existing drainage will be rerouted around the building.

2 Geotechnical Report March 31, 17 Proposed Volvo Dealership Page 2 TEST BORINGS New England Boring Contractors, Inc. of Brockton, Massachusetts drilled five () test borings on March 23, 17 within the footprint of the proposed building to a maximum depth of 14 feet below grade. Boring operations were supervised by Mr. Stephen Reynolds of HML Associates. Borings B-2 through B- terminated at auger refusal between 2. and 11 feet below grade. Multiple attempts were made at each boring location to advance the borehole. Boring locations are shown on Figure 3. Boring logs are included in Appendix 2. Borings were advanced by a truck mounted rotary drill rig using 4-1/2 in ID hollow stem augers. Soil samples from the test borings were collected at the depths indicated on the boring logs to the bottom of the borehole using a 1-3/8-inch inner diameter by 2-inch outer diameter 24-inch long split-barrel sampler. The sampler was inserted into the auger, and then advanced into undisturbed material using a 14-lb safety hammer free falling a distance of inches as described in ASTM D Soil samples obtained from the test borings were classified in the field by visual and textural examination in accordance with ASTM D 2487 and These classifications were later confirmed through further examination and final test boring logs prepared. SUBSURFACE CONDITIONS The following subsurface conditions were encountered when the test borings were drilled at the proposed building location: Gravelly Sand Fill was encountered at the ground surface at all boring locations. The fill was less than 1 foot thick except at B-2 where about feet of fill was encountered. Medium dense to very dense Gravelly Sand, Sand and Silty Sand were encountered below the Fill at all boring locations except B-4 were it was not encountered. Glacial Till, consisting very dense gravelly sand, was encountered at all boring locations between 1 and 9 feet below grade and extended to 14 feet below grade, the maximum depth explored. Augers refusal was encountered at B-2 through B-. The shallow refusals may be the result of large boulders or an area of shallow bedrock. GROUNDWATER Groundwater was encountered at about 8 feet below existing grade at B-1 and B-2 only at the completion of the test borings. Groundwater levels may vary with season, precipitation, construction activity in the area and other factors. Therefore, water levels encountered during construction may be different than those encountered at the time of drilling.

3 Geotechnical Report March 31, 17 Proposed Volvo Dealership Page 3 RECOMMENDATIONS FOR FOUNDATION DESIGN AND CONSTRUCTION Foundation Design Considerations We recommend supporting the proposed building on a shallow foundation of spread and/or strip footings with a slab on grade. The recommended maximum net allowable bearing pressure for footings bearing on structural backfill, the naturally occurring sand/gravelly sand/silty or glacial till is 6 psf. Total estimated settlement due to compression of the bearing soils will be less than 1 inch, and differential settlement will be less than. inches. With exterior grades around the perimeter of the building of to 147.3, the bottom of exterior footings would be between 142.7, to feet. With a shallow refusal of only 2. feet below grade at B-4, it is possible that bedrock may be encountered above the bottom of footing elevation. If this is the case, we recommend removing the bedrock to 9 inches below the bottom of the footing and replacing with compacted structural backfill. Spread footings should have a minimum dimension of 36 inches, while strip footings should have a minimum dimension of 24 inches. All exterior footings bearing on soil must be located at least 4 feet below final finished exterior grades to provide adequate frost protection. In permanently heated locations, the bottom of footings should be a minimum of 18 inches below the top of the slab. We recommend that the floor slab be designed as a slab on grade and be supported on a 12-inch thick layer of ¾ to 1-1/2 inch crushed stone or structural backfill. A modulus of subgrade reaction of 1 pci can be used in floor slab design. Dampproofing Groundwater levels encountered in the test borings were below the permanent structure. Therefore, the foundations including the floor slab will not be subjected to unbalanced hydrostatic forces and no waterproofing is required. All exterior foundation walls should be dampproofed starting from the top of the footing to above ground surface as required by Section of the 9 International Building Code (IBC). Where installed beneath the slab, dampproofing shall consist of not less than 6-mil (.6 inch;.12 mm) polyethylene with joints lapped not less than 6 inches (12 mm),or other approved methods or materials as required by Section of the IBC. An evaluation of the need to control humidity to prevent the formation of mold and other organisms within the building was not within our scope of work. Seismic Design Based on Table of the 8 th Edition of the Massachusetts Building Code, the Earthquake Design Factors for Rockland are Ss =.26 and S 1 =.64. The Site Class is C using the criteria found in Table of the 9 IBC. Based on HML Associates evaluation of the soil data obtained at the site, we conclude that the soil below the site including the fill is not susceptible to liquefaction. Compacted granular fills are not considered subject to liquefaction, provided they are compacted to at least

4 Geotechnical Report March 31, 17 Proposed Volvo Dealership Page 4 93% of the maximum dry density as determined in the laboratory test designated ASTM D 17. Construction Considerations Excavation Overburden soils including the fill, sand and till can be excavated by conventional earthmoving equipment. Shallow bedrock or a large boulder may be encountered in the vicinity of Boring B-4. If bedrock or a large boulder is encountered within 9 inches of the bottom of a footing, it must be removed to a depth of 9 inches below the bottom of the footing and the resulting excavation backfill with structural backfill. Unsuitable material is defined as surficial organics, surficial and buried topsoil and subsoil, building foundations and pavement, underground utilities and structures and compressible and deleterious materials. Below the footings for the proposed building, unsuitable material must be completely removed to undisturbed sand or glacial till within an area defined by a one horizontal to one vertical (1H:1V) line sloping down from 2 feet outside the bottom edge of the footings to the top of undisturbed sand or glacial till whichever occurs first. Unsuitable material must also be removed from beneath the floor slab. Backfilling Structural Fill Backfill below and around foundations, slabs on grade, paved areas and other structural elements should consist of clean, well-graded sand and gravel free of organic material, trash, ice, frozen soil, and other deleterious materials. The recommended gradation for structural fill should satisfy the following limits. Percent Finer by Weight U.S. Sieve Size and Number Minimum Maximum 3 inch /2 inch 8 No No No. 8 Granular Fill Granular backfill can be used below proposed pavements and building slabs to within one foot of the underside of the slabs and pavement. Granular fill is not suitable under the footing stress zone or three feet laterally either side of foundation walls or directly behind retaining walls. Granular fill should consist of clean, sand and gravel free of organic material, trash, ice, frozen soil, and other deleterious materials. The recommended gradation for granular fill should satisfy the following limits.

5 Geotechnical Report March 31, 17 Proposed Volvo Dealership Page Percent Finer by Weight U.S. Sieve Size and Number Minimum Maximum 4 inch inch 1 6 No No. 12 The moisture content of the fill materials should be adjusted prior to placement so that they are within 2 percent of the optimum moisture content. Fill should be placed in loose lifts not exceeding 12 inches in thickness and compacted with a minimum of 4 passes of a vibratory drum compactor or large plate compactor to a dry density of at least 9 percent of the maximum dry density as determined by the laboratory test designated ASTM D 17, Method C. In confined areas including trenches or adjacent to walls, small hand operated equipment such as a walk behind vibratory compactor should be used. Subgrade Preparation and Protection Critical aspects of foundation construction are protecting all bearing strata from disturbance and removing any unsuitable fill, or loose or disturbed soil. Excavations should be protected from flooding by surface water runoff, groundwater intrusion and freezing, and worker and equipment traffic over bearing surfaces must be minimized. We recommend that all bearing surfaces be inspected and approved by the geotechnical engineer prior to placing fill or foundation concrete Where bearing strata are disturbed, the extent of disturbance must be evaluated by the geotechnical engineer and appropriate remedial action measures taken such as removing and replacing disturbed soils. We also recommended proof rolling the bearing surface with a minimum of 4 passes of a vibratory plate compactor. Soil bearing surfaces must be protected from freezing before and after foundation construction. If construction takes place in subfreezing conditions, footings must be backfilled as soon as possible after the concrete is poured or insulating blankets, heating or other measures may be taken to keep the ground from freezing. Groundwater and Surface Water Control Groundwater was encountered in the test borings at 8 feet below grade. Therefore, it is anticipated that groundwater will not be encountered during building construction. If groundwater is encountered in the excavation, it can be controlled locally with sumps and pumps. Water generated from dewatering activities or collected from excavated materials should be recharged to the ground in the immediate area of the subsurface work or discharged to the storm drains. Water discharged to the existing municipal storm drain system must be in accordance with National Pollutant Discharge Elimination System (NPDES) criteria. Groundwater pumped from uncontaminated areas is considered general construction dewatering and its discharge to the storm drain system must be permitted under the NPDES General Permit for Construction Dewatering Activity

6 Geotechnical Report March 31, 17 Proposed Volvo Dealership Page 6 Discharges. Efforts should be made to limit the amount of groundwater generated from dewatering/excavation activities and to recharge as much of the generated groundwater as possible. Surficial runoff due to heavy rains during construction should be controlled and directed away from foundation excavations in order to maintain stable foundation bearing surfaces. Any bearing soils disturbed by surface water or groundwater must be removed and replaced with crushed stone or structural fill prior to placement of any additional structural backfill and foundation concrete. The site should be graded to direct surface water away from the buildings. In addition, to limit infiltration adjacent to foundation walls, we recommend that the last 6 to 9 inches of backfill placed within 1 feet of the buildings consist of low permeability soil such as silty topsoil or other similar soil. Construction Monitoring We recommend that an HML Associates geotechnical field representative be present to observe and document the geotechnical aspects of the project in order to verify compliance with the requirements of the Massachusetts State Building Code and the recommendations contained in this report. The field representative will: Investigate subsurface condition below that portion the proposed building that could not be explored because it was covered by the existing building. Monitor the removal of unsuitable materials including removal of the existing building foundation, utilities and topsoil and subsoil and verify the conditions of the bearing strata. Observe the preparation of slab, footing and fill subgrade surfaces. Confirm that backfill materials meet the project specifications. Facilitate reuse of excavated materials and make judgments regarding the suitability of excavated soil for reuse as fill. Observe placement and test compaction of fill material.

7 Geotechnical Report March 31, 17 Proposed Volvo Dealership Page 7 LIMITATIONS The conclusions expressed by HML Associates in this report are based solely on the references cited. Observations, analyses, and recommendations were made under the conditions stated and where information was provided by others it was relied upon as complete. The purpose of this study was to establish by a limited scope of work subsurface soil conditions and to provide recommendations for foundation design and construction and earthwork operations. The nature and extent of soil conditions are developed through both engineering and geological interpretations and variations between the investigation and the actual soil conditions may not become evident until construction. If differences are found, HML Associates should be given the opportunity to reevaluate the recommendations of this report. In the event that changes in preliminary design, specifications, or location of the proposed foundations are planned, the conditions and recommendations contained in this report shall not be considered valid unless HML Associates can review and modify them as necessary. Thank you for the opportunity to be of service on this project. Should you have any questions regarding the contents of this report, please feel free to contact us. Sincerely, HML Associates Nicholas A. Lanney, P.E. Principal Figure 1 Figure 2 Figure 2 Group) Appendix 1 Appendix 2 Site Locus Map Existing Conditions Plan (Plan from Kelly Engineering Group) Site Plan and Boring Location Plan (Based Map from Kelly Engineering Site Photographs HML Associates Test Boring Logs

8 SITE HML ASSOCIATES Site Locus Map Proposed Volvo Dealership 122 Hingham Street Rockland, Massachusetts FIGURE 1

9 Steven M. Horsfall :42:47 -'' FIGURE 2 EXISITING CONDITIONS PLAN M.

10 B-1 B- B-3 B-4 B-2 B-1 FIGURE 3 SITE PLAN & BORING LOCATION PLAN Digitally signed by David Noel Kelly DN: cn=david Noel Kelly, o=kelly Engineering Group, Inc., ou=president, =dkelly@kellyengineerin ggroup.com, c=us Date: :31:43 -'' DAVID NOEL KELLY CIVIL

11 APPENDIX 1 SITE PHOTOGRAPHS

12 Looking South Toward Hingham Street

13 Looking Northwest at Proposed Volvo Dealership Site - Hyundai Dealership in background

14 APPENDIX 2 HML ASSOCIATES TEST BORING LOGS

15 HML ASSOCIATES Location: 122 HINGHAM ST.,ROCKLAND, MA Method: 4-1/2" I.D. Augers Boring Log No. B-1 VOLVO AUTO DEALERSHIP Client: PRIME MOTOR GROUP Ground EL: N/A Hammer: Safety Hammer weight (lb): 14 Hole depth (ft): 14. SuperLog CivilTech Software, USA File: C:\Users\Nick Lanney\Documents\Projects 17\176 prime volvo\prime Rockland Volvo b1.log Date: 4/1/17 Sampler: 2" OD Split-spoon Driller: Depth Strata GWT No. Type Blows Per 6" USCS Drop (in): Soil Description Drilling (ft): 8 ft Drill Date: 3/23/17 SM-SP FILL: GRAVELLY SAND, poorly graded, 1-2% SP-SM gravel, coarse to fine sand, mostly fine, 8-12% SP nonplastic fines, brown gray SAND, uniform, fine to very fine, -1% nonplastic fines, light brown gray SAND, poorly graded, medium to fine, 3-% nonplastic fines, light gray brown, trace of coarse sand and fine gravel. SP-SM TILL: GRAVELLY SAND, poorly graded, 2-% gravel, coarse to fine sand, mostly medium to fine, 8-12% nonplastic fines, saturated, light gray brown. END Boring completed at depth of 14. ft. Augered to 14 ft. through till. No sampling due to 2 ft of sand blow in inside augers. SPT. blow/ft Moisture % 4 6 Driller: NEW ENGLANG BORING Logged by: S. REYNOLDS + Notes Remarks: 3 Plate 1

16 HML ASSOCIATES Location: 122 HINGHAM ST.,ROCKLAND, MA Method: 4-1/2" I.D.Augers Boring Log No. B-2 VOLVO AUTO DEALERSHIP Client: PRIME MOTOR GROUP Ground EL: N/A Hammer: Safety Hammer weight (lb): 14 Hole depth (ft): 11 SuperLog CivilTech Software, USA File: C:\Users\Nick Lanney\Documents\Projects 17\176 prime volvo\prime Rockland Volvo b1.log Date: 4/1/17 Sampler: 2" OD Split-spoon Driller: Depth Strata GWT No. Type Blows Per 6" USCS Drop (in): Soil Description Drilling (ft): 8 ft Drill Date: 3/23/17 SM-SP FILL: GRAVELLY SAND, poorly graded, 1-2% SP-SM gravel, coarse to fine sand, mostly fine, 8-12% nonplastic fines, brown gray GRAVELLY SAND, poorly graded, 1-2% gravel, coarse to fine sand, mostly fine, -12% nonplastic fines, gray, pockets of fine sand. Possible Fill SP-SM SAND, uniform, fine to very fine, -1% nonplastic fines, light brown gray SP SAND, poorly graded, medium to fine, 3-% END nonplastic fines, light gray brown, trace of coarse sand and fine gravel. Boring completed at depth of 11. ft. Augered refusal at 11 Ft. Location was moved ft after 3 ft refusal SPT. blow/ft Moisture % 4 6+ Driller: NEW ENGLANG BORING Logged by: S. REYNOLDS + + Notes Remarks: 3 Plate 2

17 HML ASSOCIATES Location: 122 HINGHAM ST.,ROCKLAND, MA Method: 4-1/2" I.D.Augers Boring Log No. B-3 VOLVO AUTO DEALERSHIP Client: PRIME MOTOR GROUP Ground EL: N/A Hammer: Safety Hammer weight (lb): 14 Hole depth (ft): 6. SuperLog CivilTech Software, USA File: C:\Users\Nick Lanney\Documents\Projects 17\176 prime volvo\prime Rockland Volvo b1.log Date: 4/1/17 Sampler: 2" OD Split-spoon Driller: Depth Strata GWT GWT not encountered No. Type Blows Per 6" USCS Drop (in): Soil Description Drilling (ft): NA Drill Date: 3/23/17 SM-SP FILL: GRAVELLY SAND, poorly graded, 1-2% SM gravel, coarse to fine sand, mostly fine, 8-12% nonplastic fines, brown gray SM SILTY SAND, widely graded, 1-% gravel, coarse to fine sand, mostly fine, 12-1% nonplastic fines, brown (subsoil) TILL: SILTY SAND, widely graded, -2% gravel, coarse to fine sand, mostly fine, 12-1% nonplastic END fines, light gray. Boring completed at depth of 6. ft. Auger refusal at 6 ft. Moved location 1 ft and auger refusal at. ft. SPT. blow/ft Moisture % 4 6+ Driller: NEW ENGLANG BORING Logged by: S. REYNOLDS + Notes Remarks: 3 Plate 3

18 HML ASSOCIATES Location: 122 HINGHAM ST.,ROCKLAND, MA Method: 4-1/2" I.D. Augers Boring Log No. B-4 VOLVO AUTO DEALERSHIP Client: PRIME MOTOR GROUP Ground EL: N/A Hammer: Safety Hammer weight (lb): 14 Hole depth (ft): 2. SuperLog CivilTech Software, USA File: C:\Users\Nick Lanney\Documents\Projects 17\176 prime volvo\prime Rockland Volvo b1.log Date: 4/1/17 Sampler: 2" OD Split-spoon Driller: Depth Strata GWT GWT not encountered No. Type Blows Per 6" USCS Drop (in): Soil Description Drilling (ft): NA Drill Date: 3/23/17 SM-SP FILL: GRAVELLY SAND, poorly graded, 1-2% SM gravel, coarse to fine sand, mostly fine, 8-12% nonplastic fines, brown gray 2 1/ END TILL: GRAVELY SAND, widely graded, -2% gravel, coarse to fine sand, mostly fine, 8-12% nonplastic fines, light gray brown. Boring completed at depth of 2. ft. Auger refusal at 2. ft. Moved location 1 ft and auger and spoon refusal at 2. ft. SPT. blow/ft Moisture % 4 6+ Driller: NEW ENGLANG BORING Logged by: S. REYNOLDS + Notes Remarks: 3 Plate 4

19 HML ASSOCIATES Location: 122 HINGHAM ST.,ROCKLAND, MA Method: 4-1/2" I.D. Augers Boring Log No. B- VOLVO AUTO DEALERSHIP Client: PRIME MOTOR GROUP Ground EL: N/A Hammer: Safety Hammer weight (lb): 14 Hole depth (ft): 6. SuperLog CivilTech Software, USA File: C:\Users\Nick Lanney\Documents\Projects 17\176 prime volvo\prime Rockland Volvo b1.log Date: 4/1/17 Sampler: 2" OD Split-spoon Driller: Depth Strata GWT GWT not encountered No. Type Blows Per 6" USCS Drop (in): Soil Description Drilling (ft): NA Drill Date: 3/23/17 SM-SP FILL: GRAVELLY SAND, poorly graded, 1-2% SM gravel, coarse to fine sand, mostly fine, 8-12% SM nonplastic fines, brown gray SILTY SAND, widely graded, -2% gravel, coarse to fine sand, mostly fine, 12-1% nonplastic fines, brown /4" TILL: SILTY SAND, widely graded, -2% gravel, END coarse to fine sand, mostly fine, 12-1% nonplastic fines, light gray. Boring completed at depth of 6. ft. Auger refusal at 6 ft. SPT. blow/ft Moisture % 4 6 Driller: NEW ENGLANG BORING Logged by: S. REYNOLDS + Notes Remarks: 3 Plate