SUBSURFACE EXPLORATION AND GEOTECHNICAL …

PROFESSIONALS, INC.

SUBSURFACE EXPLORATION AND

GEOTECHNICAL ENGINEERING EVALUATION

PROPOSED DOLLAR GENERAL STORE

NEW BRIDGE ROAD (VA ROUTE 208)

MINERAL, VIRGINIA

EAS 13-328

Prepared For:

JR LEX, LLC 955 Old Cherokee Road

Lexington, South Carolina 29072

Prepared By:

EAS PROFESSIONALS, INC. 153 Brozzini Court, Suite C

Greenville, South Carolina 29615 Phone: (864) 234-7368 • Fax: (864) 234-7369

July 26, 2013

PROFESSIONALS, INC.

Geotechnical and Civil Engineering − Construction Materials Testing − Environmental

Laboratory Testing − Land Surveying − Specialty Inspections

153 Brozzini Ct., Suite C

Greenville, SC 29615

Phone (864) 234−7368

Fax (864) 234−7369

July 26, 2013 JR Lex, LLC 955 Old Cherokee Road Lexington, South Carolina 29072 Attention: Mr. Robby Wilkins Reference: Report of Subsurface Exploration and

Geotechnical Engineering Evaluation Proposed Dollar General Store New Bridge Road (VA Route 208) Mineral, Louisa County, Virginia EAS Project Number: EAS 13-328 Mr. Wilkins: The purpose of this report is to present the results of the subsurface exploration program and geotechnical engineering analyses undertaken by Engineering and Surveying Professionals, Inc. (EAS) in connection with the above referenced project in Mineral, Virginia. The attached report presents our understanding of the project information provided to EAS, reviews our exploration procedures, describes existing site and general subsurface conditions, and presents our evaluations, conclusions, and recommendations. We have enjoyed working with you on this project, and we are prepared to assist you with the recommended quality assurance monitoring and testing services during construction. Please do not hesitate to contact us if you have any questions regarding this report or if we may be of further service. Sincerely,

EAS PROFESSIONALS, INC.

Ryan D. Rafalski Douglas R. Dunko, PE Project Engineer Senior Geotechnical Engineer Virginia Registration No. 0402046367

7-26-13

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______________________________________________________________________________ Dollar General Store Page 1 EAS Project No. EAS 13−328

Mineral, Virginia July 26, 2013

TABLE OF CONTENTS PAGE

1.0 EXECUTIVE SUMMARY OUTLINE ............................................................................... 2

2.0 SCOPE OF SERVICES ........................................................................................................ 4

3.0 SITE AND PROJECT DESCRIPTION ............................................................................... 4

4.0 SUBSURFACE EXPLORATION ....................................................................................... 5

5.0 ENGINEERING EVALUATION AND RECOMMENDATIONS .................................. 8

5.1 Site Preparation Recommendations ...................................................................8

5.2 Structural Fill Placement and Compaction ........................................................9

5.3 Fill Slopes ........................................................................................................11

5.4 Foundations ......................................................................................................12

5.5 Floor Slabs .......................................................................................................13

5.6 Site Seismic Classification ...............................................................................14

5.7 Pavement Design and Recommendations ........................................................15

5.8 Temporary Excavation Recommendations ......................................................18

6.0 CONSTRUCTION OBSERVATIONS AND TESTING ................................................ 18

7.0 LIMITATIONS .................................................................................................................. 20

FIGURES SITE VICINITY PLAN, FIGURE No. 1 BORING LOCATION PLAN, FIGURE No. 2

APPENDIX A KEY TO BORING LOG SOIL CLASSIFICATIONS SPT BORING LOGS

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1.0 EXECUTIVE SUMMARY OUTLINE The executive summary is provided solely for purpose of overview. Any party who relies on this report must read the full report. The executive summary omits a number of details, any one of which could be critical to the proper application of this report. Subsurface Conditions

• The soil test borings within the development area generally encountered residual soils to depths of approximately 10 to 20 feet below existing site grades. The residual soils generally consisted of interbedded silty and/or sandy CLAY (CL) and clayey and/or sandy SILT (ML) soils. Layers of silty and/or clayey SAND (SM/SC) soils were encountered at 2 of the 7 soil test boring locations. Standard Penetration Resistance (SPT) N-values of the sampled residual soils ranged from 7 to 41 blows per foot (bpf) with an average of 16 bpf, which indicated medium stiff/loose to hard/dense soil conditions of the soils encountered at the soil test boring locations.

• Ground water was not encountered at any of the soil test boring locations during drilling activities or prior to backfilling the boreholes after several hours before leaving the site.

Site Preparation

• Site Demolition: The property is currently occupied by an abandoned residence with associated out-buildings and a barn. Initial site preparation will require the removal of the existing building structure, slabs and pavements within the proposed development area. A small well pump house is located immediately south of the abandoned residence and an old well is located south of the pump house. These wells should be properly abandoned prior to site development. Any other existing utilities (e.g., storm water lines, septic tanks, sanitary sewer lines, etc.) that are encountered within the proposed development area should be abandoned and/or removed. Open pipes or conduits, if any, left in-place adjacent to the construction area should be bulkheaded and grouted as they might serve as conduits for subsurface erosion.

• All areas to receive engineered fill, foundations and/or pavements should be proofrolled with a loaded tandem axle dump truck, scraper, or other similar heavy construction equipment to confirm the stability of the subgrade soils and detect the presence of any near surface soft or unstable areas. EAS’s geotechnical engineer or his representative should observe the proofrolling operations. Based on the results of the soil test borings, we do not anticipate that widespread areas of unstable subgrade will be encountered across the site.

• The site CLAY (CL) and SILT (ML) soils encountered at the soil test borings are very moisture sensitive and can become unstable during normal construction traffic and activities when wet. During earthwork and construction activities, surface water runoff should be drained away from the construction areas to prevent water from ponding on or saturating the soils within excavations or on subgrades.

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Structural Fill

• Based on the observed site grades, we anticipate that up to approximately 10 feet of structural fill will be required to achieve finish subgrade elevations increasing in depth towards the south/southwestern portion of the planned development area.

• The SILT (ML) and CLAY (CL) site soils are marginally suitable for use as structural fill and will require a high degree of quality control during structural fill placement. If used the grading contractor should be prepared to moisture condition (wet) these soils prior to placement.

Fill Slopes

• A formal slope stability analysis of the anticipated structural fill slopes was beyond the scope of this subsurface exploration and geotechnical analysis; however, EAS recommends a maximum slope of 3H: 1V for structural fill slopes consisting of soils similar to the SILT (ML) and CLAY (CL) soils encountered at the soil test borings. Fill slopes less than 10 feet in height should be stable provided the structural fill soils are properly moisture conditioned, placed with a relatively high degree of compaction (minimum 95% of standard Proctor), and full time observation and monitoring of EAS’s Geotechnical engineer and/or technician during construction.

Foundations

• Foundations can be designed for a 2,500 psf maximum net allowable soil bearing pressure. Actual foundation sizes/depths and steel reinforcement should be determined by the project structural engineer based on actual design loads, building code requirements and other structural considerations.

Site Seismic Classification

• Based upon the subsurface conditions encountered at the soil test borings and in accordance with section 1613.5.2 of the 2009 IBC, the subject site currently meets the conditions for a Site Classification D, for sites with a stiff soil profile where 15 bpf < the average N-value < 50 bpf.

• Based on the design spectral response accelerations and the structure’s seismic use group, the site is assigned a Seismic Design Category B for SDS and SD1 in general accordance with the procedures outlined in section 1613.5.6 of the 2009 IBC.

Pavements

• Based on the encountered soil conditions at the soil test boring locations and anticipated subgrade soil conditions upon completion of site preparation and proper placement of structural fill, the minimum pavement sections for flexible and rigid pavement in accordance with Dollar General Specifications can be used.

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2.0 SCOPE OF SERVICES The purposes of our involvement on this project were as follows: 1) provide general descriptions of the subsurface conditions encountered at the project site, 2) provide shallow foundation and pavement design recommendations, and 3) comment on geotechnical aspects of the proposed construction. In order to accomplish the above objectives, we undertook the following scope of services:

1) Visited the site to observe existing surface conditions and to field locate the soil test boring locations.

2) Coordinated utility clearance with applicable utility services. 3) Reviewed readily available geologic and subsurface information relative to the

project site. 4) Executed a subsurface exploration consisting of seven soil test borings with split-

spoon testing (SPT): four borings within the proposed building footprint (B-1 through B-4) and three borings within planned pavement areas (P-1 through P-3). The borings were drilled to planned depths ranging from 10 feet to 20 feet below existing site grades.

5) Evaluated the findings of the soil test borings relative to general subsurface characterization, foundation and pavement support, and other geotechnical aspects of the project.

6) Prepared this written report summarizing our services for the project, providing

descriptions of the subsurface conditions encountered, foundation, and pavement design recommendations, as well as geotechnical considerations for construction. Copies of the boring logs are provided in Appendix A.

3.0 SITE AND PROJECT DESCRIPTION We understand that JR Lex, LLC is considering construction of a new Dollar General store on an approximate 2.1-acre tract located adjacent to the south side of New Bridge Road (VA Route 208) on the east side of its intersection with Kentucky Springs Road in Mineral, Louisa County, Virginia. A Preliminary Site Plan dated August 23, 2012 was provided to EAS for our use in preparing this report. A topographic survey by Freeland-Clinkscales & Associates, Inc. of NC dated December 12, 2012 was also provided. The proposed construction will consist of an approximate 9,100 square foot (SF) building with associated paved parking and drive areas. A new storm water management pond will be required for the planned development. The subject 2.1-acre property is developed with an abandoned residence, a garage/barn structure, a shed and a well house. Various refuse materials consisting of construction materials, scrap

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metal and car parts were observed within and surrounding the shed/out-building. The balance of the site consisted of grassed areas surrounding the residence and dense underbrush and trees within the south/southwestern portion of the property. An overhead power line extends along the general eastern boundary of the site. The site topography generally slopes from the north/northeast towards the south/southwest across the project site with approximately 10 feet of elevation change across the planned development area. The project involves construction of a new single-story metal frame building with a footprint of approximately 130 feet by 70 feet. Structural loads were not provided to us; however, based upon our past experience, we have assumed that the building will likely require shallow foundation with column and continuous wall footings that have loads of up to approximately 30 kips and 1 kip per linear foot, respectively. Heavy duty pavement will be used within the planned drive areas with standard duty pavement utilized within the parking areas. Our assumptions for traffic loading for the recommended pavement sections are outlined/discussed in the Pavement Design and Recommendations section of this report. Final grading information was not provided to us; however, based on review of the provided topographic survey we anticipate that up to approximately 10 feet of structural fill will be required to achieve finish subgrade elevations for the planned development increasing in depth towards the south/southwestern portion of the planned development area. The anticipated fill grading required to achieve finish subgrade elevations for the planned development will likely result in structural fill slopes as part of the final grading plan. We anticipate that any required structural fill will may be derived from excavation of the planned storm water management pond and/or imported from an off-site source. The information presented in this section was used in our evaluation for the planned development. Estimated loads and corresponding foundation sizes have a direct affect on the recommendations, including the type of foundation, the allowable bearing pressure, and settlement due to foundation loads. In addition, estimated finish subgrade elevations and assumed cut/fill grading quantities can have a direct affect on the provided recommendations. If any of the noted/assumed information is incorrect or has changed, please inform EAS so that we may amend the recommendations presented in this report, if necessary. 4.0 SUBSURFACE EXPLORATION Seven (7) soil test borings with split-spoon testing (SPT) were drilled for this project to depths of approximately 10 to 20 feet below existing site grades. The borings were located in the field based on the provided site plan by an EAS representative by making tape measurements from known site features. Given the method of determination, the boring locations should only be considered approximate. The approximate test boring locations are indicated on the Boring Location Plan (Figure No. 2) enclosed in the Appendix to this report. The soil test borings were advanced using hollow stem augers for borehole stabilization. Representative soil samples were obtained using a standard two-inch outside diameter (O.D.) split barrel sampler in general compliance with ASTM Standards. The number of blows required

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to drive the split barrel sampler three consecutive 6-inch increments is recorded and the blows of the last two 6-inch increments are added to obtain the Standard Penetration Test (SPT) N-values representing the penetration resistance of the soil. Standard Penetration Tests were performed at frequent intervals to evaluate the consistency and general engineering properties of the subsurface soils. Representative portions of the soil samples obtained from each SPT interval were sealed in a container, labeled and transported to our laboratory for final classification by our geotechnical staff. The soil samples were visually classified in general accordance with the Unified Soil Classification System (USCS), using visual-manual identification procedures (ASTM Method D 2488). Copies of the Boring Logs are enclosed in Appendix A. Regional Geology The proposed Dollar General development is located in the Piedmont physiographic region of Virginia. The Piedmont is categorized by rolling hills and valleys and denudational terrain the result of physical weathering of previous mountainous terrain. Drainage features tend to be dendritic in nature, resulting from differential weathering of fractured rock sets due to faulting and resulting weakening of bedrock. According to maps of the United States Geologic Survey, the project site is underlain by metamorphosed volcanic rocks of the Chopawamsic Formation. These rocks are primarily composed of metamorphosed laterally discontinuous lenses and tongues of felsic, intermediate, and mafic volcanic flows and volcanoclastic rocks, with interlayered quartzite, quartzose graywacke, schist, and phyllite of Cambrian age, interpreted as representing an ancient island-arc sequence. These rocks tend to weather to sands, silts, and clays with mica present. In residual soils the rock fabric is often present. No unusual geologic hazards are present in the Piedmont physiographic region except the potential of unstable clay soils. Subsurface Conditions This section of the report provides a general discussion of the subsurface conditions encountered within areas of proposed construction at the project site. The subsurface conditions discussed in the following paragraphs and those shown on the boring logs represent an estimate of the subsurface conditions based on interpretation of the boring data using normally accepted geotechnical engineering judgments. The transitions between different soil strata are usually less distinct than those shown on the boring logs. Although individual test borings are representative of the subsurface conditions at the boring locations on the dates shown, they are not necessarily indicative of subsurface conditions at other locations or at other times. The soil test borings were drilled within the grassed areas or dense underbrush areas surrounding the existing residence and associated out-buildings. The soil test borings generally encountered residual soils below the existing ground surface (surficial soils) to the boring termination depths. The materials encountered in our soil test borings are generally discussed in the following paragraphs. The following discussion of the subsurface conditions has been simplified for ease

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of report interpretation. More detailed descriptions of the subsurface conditions at the individual boring locations are presented on the Boring Logs in Appendix A. Surficial/Organic Laden Soils Surficial soils typically contain root mat and/or other fibrous organic matter and are generally unsuitable for engineering purposes. Surficial soils containing significant root and organic content were generally observed to depths of approximately 4 to 6 inches at the soil test boring locations. Actual surficial soil depths may vary in unexplored areas of the site. For stripping estimates, we do not anticipate that the surficial soil depths will vary greatly from those encountered at the soil test boring locations. Residual Soils Residual soils were encountered at all of the soil test borings below the existing ground surface to depths of approximately 10 to 20 feet below existing site grades. Sampled residual soils were described as interbedded silty and/or sandy CLAY (CL) and clayey and/or sandy SILT (ML) soils. Layers of silty and/or clayey SAND (SM/SC) soils were encountered at 2 of the 7 soil test boring locations. Standard Penetration Resistance (SPT) N-values of the sampled residual soils ranged from 7 to 41 blows per foot (bpf) with an average of 16 bpf, which indicated medium stiff/loose to hard/dense soil conditions of the soils encountered at the soil test boring locations. Ground Water

Ground water was not encountered at any of the soil test boring locations during drilling activities or prior to backfilling the boreholes after several hours before leaving the site. The soil test borings were backfilled with auger cuttings upon completion of drilling activities. Based on these ground water observations and assumptions regarding site grading outlined in this report, shallow ground water should not affect site grading or foundation and utility excavations. We note that the elevation of the groundwater table is dependent upon seasonal factors, such as precipitation and temperature. Therefore, the elevation of the groundwater table may be different at other times of the year and from the elevations presented in this report. Generally, the highest groundwater levels occur in late winter and early spring; and the lowest levels in late summer and early fall. If earthwork, foundation construction, or pavement construction is performed during seasonally high ground water levels (typically November to May) or soon after periods of significant precipitation, the subgrade soils may become saturated (pump) and require undercutting and/or remediation measures to provide a stable subgrade for building and pavement loads and any structural fill. Typical Remediation measures include: discing and aerating the soil during dry weather; mixing the soil with drier materials; removing and replacing the soil with an approved fill material; or mixing the soil with an approved lime or cement product. Our firm should be consulted prior to implementing remedial measures to observe the unstable subgrade conditions and provide appropriate recommendations.

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5.0 ENGINEERING EVALUATION AND RECOMMENDATIONS The following evaluations and recommendations contained in this section of the report are based on the results of the 7 soil test borings, site observations, interpretation of the field data obtained during this exploration, and information provided regarding the proposed development. Provided our recommendations are strictly followed throughout the design and construction phases of this project the project site is suitable for the proposed construction. Soil penetration data have been used to estimate an allowable bearing pressure range and settlement using established correlations. Subsurface conditions in unexplored locations may vary from those encountered. If structure locations, loadings, or elevations are changed, we request that we be advised so that we may re-evaluate our recommendations. Determination of an appropriate foundation system for a given structure is dependent on the proposed structural loads, soil conditions, and construction constraints such as proximity to other structures, etc. The subsurface exploration aids the geotechnical engineer in determining the soil stratum appropriate for structural support. This determination includes considerations with regard to both allowable bearing capacity and compressibility of the soil strata. In addition, since the method of construction greatly affects the soils intended for structural support, consideration must be given to the implementation of suitable methods of site preparation, fill compaction, and other aspects of construction. 5.1 SITE PREPARATION RECOMMENDATIONS Initial site preparation will consist of demolition of the existing abandoned residence, garage/barn structure and associated out-buildings at the site. Demolition should include removal of any building slabs, pavements, existing utilities, and other deleterious non-soil materials from within the proposed development area. All existing organic laden soils, vegetation, and surface soils containing organic matter or other deleterious materials should be removed from within the proposed development area. A small well pump house is located immediately south of the abandoned residence and an old well is located south of the pump house. These wells should be properly abandoned prior to site development. Any other existing utilities (e.g., storm water lines, septic tanks, sanitary sewer lines, etc.) that are encountered within the proposed development area should be abandoned and/or removed. The resulting excavations should be backfilled with controlled structural fill placed in accordance with the recommendations presented in subsequent sections of this report. Open pipes or conduits, if any, left in-place adjacent to the construction area should be bulkheaded and grouted as they might serve as conduits for subsurface erosion. During the demolition and clearing operations, positive surface drainage should be maintained to prevent the accumulation of water in construction areas. Our geotechnical engineer or qualified engineering technician working under the supervision of our geotechnical engineer should observe site preparation activities on a full time basis.

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Following demolition and initial site preparation activities, we recommend that all areas to receive engineered fill, foundations, and or pavements be proofrolled with a loaded tandem axle dump truck, scraper, or other similar heavy construction equipment to confirm the stability of the subgrade soils and detect the presence of any near surface soft or unstable areas. EAS’s geotechnical engineer or his representative should observe the proofrolling operations. Proofrolling should be performed during a time of good weather and not while the site is wet, frozen, or severely desiccated. The proofrolling observation is a good opportunity for the geotechnical engineer to locate inconsistencies intermediate of our boring locations in the existing subgrade. If proofrolling reveals unstable conditions, the method of repair should be as directed by EAS’s project geotechnical engineer, but will likely consist of undercutting the unsuitable soils and replacement with adequately compacted structural fill. Based on the results of the soil test borings, we do not anticipate that widespread areas of unstable subgrade will be encountered across the site. The on-site CLAY (CL) and SILT (ML) soils are very moisture sensitive and can become unstable during normal construction traffic and activities when wet. As such, during earthwork and construction activities, surface water runoff should be drained away from the construction areas to prevent water from ponding on or saturating the soils within excavations or on subgrades. However, if the subgrade should become desiccated, the affected soils should be removed and replaced or the materials should be scarified, moisture conditioned (wetted) and recompacted prior to placement of additional fill, slabs, or pavements, etc. It is imperative to maintain the specified moisture levels in the clay soils prior to placement. It is important to note that if water is needed to moisture condition (wet) the clay it typically takes 12 to 24 hours for the clay to hydrate the added water and be workable with uniform moisture content for compaction. Earthwork construction during seasonally wet times of the year (typically October to May) may result in soft subgrade conditions, difficulties in properly placing and compacting the on-site soils and possible undercutting in excess than would otherwise be expected. 5.2 STRUCTURAL FILL PLACEMENT AND COMPACTION Final grading information was not provided to us; however, based on review of the provided topographic survey we anticipate that up to approximately 10 feet of structural fill will be required to achieve finish subgrade elevations for the planned development increasing in depth towards the south/southwestern portion of the planned development area. We anticipate that any required structural fill will may be derived from excavation of the planned storm water management pond and/or imported from an off-site source. The SILT (ML) and/or CLAY (CL) site soils are marginally suitable for use as structural fill and will require a high degree of quality control during structural fill placement. The sampled site soils were relatively dry of anticipated optimum moisture contents and the grading contractor should be prepared to moisture condition (wet) the soils prior to use as structural fill. Any imported fill soils should be approved by EAS’s project geotechnical engineer. Generally, structural fill should consist of non-expansive soils having a maximum dry density of at least 95 pcf, and be free of organic and other

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deleterious materials. We recommend that our geotechnical engineer or his representative help identify the best-suited engineering fill soils. EAS recommends that earthwork operations be performed during the seasonally drier months (typically May to October) when weather conditions are more conducive to soil moisture conditioning (e.g. drying) and achieving proper compaction of structural fill. It should also be noted that any excavated soils that are intended to be used as structural fill may be wet of optimum conditions, which will also require adequate drying time prior to use as structural fill. If earthwork is performed during the seasonally wet months, it may be more difficult to properly compact structural fill and additional subgrade undercutting and repair will likely be required. New structural fill should be adequately keyed into existing subgrade soils that have been stripped and scarified to a depth of 6 to 8 inches, exposing acceptable subgrade soils. All structural earth fill and existing clay subgrade soils should be placed in loose lifts not exceeding 8-inches and be compacted to at least 95 percent of the standard Proctor maximum dry density value as determined by ASTM D-698. All clay fills and scarified clay subgrades which receive fill should be compacted at a moisture content of at least 2 percent over the soil’s optimum moisture content (as determined by ASTM Test Method D-698). It is imperative to maintain the specified moisture levels in the clay (CL) soils prior to placement. Additionally, it is important to note that if water is needed to moisture condition (wet) the clay it typically takes 12 to 24 hours for the clay to hydrate the added water and be workable with uniform moisture content for compaction. Placing and compacting the clayey soils at moisture contents above the optimum moisture content is intended to reduce the potential for post construction heave of the compacted clay material. The top 18-inches of fill in load bearing areas should be compacted to at least 98 percent of the standard Proctor value. The aggregate base course (underlying asphalt pavements and building floor slab) should be compacted to least 95 percent of the material's maximum dry density as determined by ASTM Test Method D1557. All structural fill should be placed under the full-time control and supervision of EAS’s geotechnical engineer or engineering technician working under the direction of our geotechnical engineer. The placement and compaction of all fill material should be tested frequently in order to confirm that the recommended degree of compaction and moisture content is obtained. We recommend that the contractor have equipment on site during earthwork for both drying and wetting of fill soils. The grading contractor should be prepared to moisture condition (wet and/or dry) the clayey site soils if used. The contractor should have available and/or onsite a water truck with a suitable spray bar for uniform application of water and equipment such as a disc or rototiller to scarify/mix and/or dry the moisture conditioned soils. Moisture control may be difficult during winter months or extended periods of rain. As previously discussed, EAS recommends that earthwork operations be performed during the seasonally drier months (typically May to October) when weather conditions are more conducive to soil moisture conditioning (e.g. drying) and achieving proper compaction of structural fill. During fill operations, positive surface drainage should be maintained to prevent the accumulation of water. Attempts to work the soils when wet can be expected to result in deterioration of

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otherwise suitable soil conditions or of previously placed and properly compacted fill. Where construction traffic or weather has disturbed the subgrade, the upper 8 inches of soils intended for structural support should be scarified and re-compacted. 5.3 FILL SLOPES As previously discussed we anticipate significant structural fill grading will be required in order to achieve finish subgrade elevations for the planned development which will likely result in structural fill slopes as part of the final grading plan. A formal slope stability analysis of the anticipated structural fill slopes was beyond the scope of this subsurface exploration and geotechnical analysis. Generally, permanent project earthen fill and cut slopes should be designed at a minimum of 2.5 horizontal to 1 vertical (2.5H: 1V) or flatter and minimum 2 horizontal to 1 vertical (2H: 1V) or flatter, respectively, to promote long and short term stability. Permanent slopes of 3H: 1V or flatter are usually desired for mowing. We recommend performing laboratory testing to determine the soil’s wet density (γwet), the soil’s dry density (γdry) and the soil’s internal angle of friction (Φ) in order to properly design/optimize the anticipated fill slopes. In general, geotechnical evaluation methods widely employed to anticipate the stability of soil cut and fill slopes under various geometries involve estimating the sliding, overturning and resisting forces of the soils involved. The critical soil properties involved in the analysis are the soil’s internal angle of friction (Φ), the soil’s wet density (γwet), and the soil’s dry density (γdry). Other factors such as the pore water pressure and the soil’s cohesion play some role in the evaluation. Sampled residual soils were generally described as interbedded silty and/or sandy CLAY (CL), clayey and/or sandy SILT (ML) soils. Layers of silty and/or clayey SAND (SM/SC) soils were encountered at 2 of the 7 soil test boring locations. Standard penetration resistance (N-values) in the sampled residuum ranged from 7 to 41 blows per foot (bpf) indicating medium stiff/loose to hard/dense soil conditions of the residual soils encountered at the soil test boring locations. The site preparation recommendations of this report should be strictly followed prior to beginning construction of any site slopes. The grading contractor should remove organic laden soils and undercut and/or re-work soft subgrade soils within the footprint of the anticipated structural fill slopes. EAS recommends a maximum slope of 3H: 1V for structural fill slopes consisting of soils similar to the SILT (ML) and CLAY (CL) soils encountered at the soil test borings. Fill slopes less than 10 feet in height should be stable provided the structural fill soils used are properly moisture conditioned, placed with a relatively high degree of compaction (minimum 95% of standard Proctor) and full time observation and monitoring of EAS’s Geotechnical engineer and/or technician during construction. All fill slopes should be constructed by overbuilding and cutting back to obtain adequate compaction along the slope face. The tops and bases of all slopes should be located a minimum of 10 feet from structural limits. Fill slopes placed over existing slopes should be adequately benched/keyed into the existing slopes so that engineering fill is not placed and/or compacted on a sloping subgrade. All fill slopes should be adequately compacted, as outlined in the structural fill placement and compaction section of this report, and all slopes should

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be seeded and maintained as soon as possible after construction. All fill slope construction should be performed under the full-time control and supervision of EAS’s geotechnical engineer or engineering technician working under the direction of our geotechnical engineer. Due to the erodable characteristics of the on-site soils, all slopes should be protected by silt fencing during construction, stabilized and hydro-seeded or similarly seeded for permanent protection. We note that surficial sloughing of the slope face soils are most likely to occur until the face of the slopes are completely stabilized with vegetation. During construction and as part of the final design, we recommend that drainage and/or run off from nearby structures be directed away from the crest and toe of both cut and fill slopes. We note that diversion of surface water away from the slope crest and face is critical to reducing the potential of surface erosion and shallow failures. For erosion protection, a protective cover of grass or other vegetation should be established on permanent soil slopes as soon as possible. Seepage and surface runoff may cause parts of the slopes to slough and erode resulting in shallow surface failures. The soil slopes should be vegetated as soon as possible to prevent surface sloughing and erosion. If sloughing or erosion occurs, the use of a vegetation mat or geotextile and large stone may be required to stabilize the slopes. A swale or shallow ditch should be constructed near the top of slopes to prevent surface water from flowing onto the slopes. We recommend that all cut and fill slopes be observed by a geotechnical engineer or his representative during construction. Additional slope drainage and protection measures may be required in certain areas depending upon conditions observed at the time of slope construction. 5.4 FOUNDATIONS The proposed Dollar General building can be supported on conventional shallow spread foundations bearing on approved stiff or better residual soils encountered at the soil test borings or properly compacted structural fill placed in accordance with structural fill recommendations in this report. Spread foundations constructed in accordance with the recommendations presented in this report can be proportioned for net allowable soil bearing pressure of 2,500 psf. All exterior foundations should bear at least 24 inches below the adjacent finished grade for bearing capacity and frost protection considerations or to the minimum depth required by the local building and codes department. Interior foundations should bear at a nominal depth of at least 1-foot. Wall and column foundations should have minimum widths of 24 and 30 inches, respectively. The project structural engineer based on the actual design loads; building code requirements and other structural considerations should determine final foundation sizes and minimum foundation excavation depths. We recommend that EAS’s geotechnical engineer or his representative evaluate the footing excavations and bearing grades prior to installation of reinforcing steel or concrete. The majority of the anticipated foundation bearing soils are anticipated to be soils suitable to support the recommended bearing pressure. Although not widely anticipated, soft zones of soils could be encountered during construction at the foundation bearing level that may require selective undercutting to repair these areas. If low consistency soils are encountered during foundation

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construction, localized undercutting and/or in-place stabilization of foundation subgrades will be required. The actual need for, and extent of, undercutting should be based on field observations and testing performed by the geotechnical engineer at the time of construction. The field-testing may consist of performing shallow hand auger borings and Dynamic Cone Penetrometer (DCP) testing of the bearing grade soils in selected areas. If soft, loose or otherwise unsuitable soils are encountered at the footing bearing level, undercutting and repair of footing subgrades will likely be recommended. Exposure to the environment may weaken the soils at the footing bearing level if excavations remain open for long periods of time. The foundation-bearing surface should be level or suitably benched and free of loose soil, ponded water and debris. If the bearing soils are softened by surface water intrusion or exposure, the softened soils must be removed from the foundation excavation immediately prior to placement of concrete. Foundation excavations must be maintained in a drained/de-watered condition throughout the foundation construction process. If the foundation excavations must remain open overnight, or if rainfall becomes imminent while the bearing soils are exposed, we recommend that a 2 to 4 inch thick “mud mat” of lean concrete (1,500 psi) be placed on the bearing soils before placing the reinforcing steel. In addition, EAS stresses the need for positive perimeter surface drainage around the building area to direct all runoff water away from the building and foundations. 5.5 FLOOR SLABS Ground floor slabs may be designed as a slab-on-grade supported by approved residual or properly compacted structural fill soils. We recommend that a modulus of subgrade reaction (k) of 125 pounds per cubic inch (pci) be used for slab design. Slab-on-grade support is contingent upon successful completion of the subgrade evaluation process as described in the Site Preparation section of this report. Although not anticipated, some subgrade undercutting and/or in-place stabilization may be necessary in soil supported slab areas underlain by low-consistency soils. The subgrade soils for support of floor slabs should be prepared as outlined in previous sections of this report. The floor slab should be supported on at least 4 inches of ABC stone (aggregate base course) compacted to 95 percent of the material’s modified Proctor maximum dry density value to provide a uniform well-compacted material immediately beneath the slab. A vapor barrier should be used beneath ground floor slabs that will be covered by tile, wood, carpet, impermeable floor coatings, and/or if other moisture-sensitive equipment or materials will be in contact with the floor. However, the use of vapor retarders may result in excessive curling of floor slabs during curing. We refer the floor slab designer to ACI 302.1R-96, Sections 4.1.5 and 11.11, for further discussion on vapor retarders, curling, and the means to minimize concrete shrinkage and curling. Proper jointing of the ground floor slab is also essential to minimize cracking. ACI suggests that unreinforced, plain concrete slabs may be jointed at spacings of 24 to 36 times the slab thickness, up to a maximum spacing of 18 feet. Floor slab construction should incorporate isolation joints

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around column locations, utility penetrations and along bearing walls and to allow minor differential movements to occur without damage to the floor. Utility or other construction excavations in the prepared floor slab subgrade should be backfilled in accordance with previously referenced structural fill criteria to aid in providing uniform floor support. 5.6 SITE SEISMIC CLASSIFICATION The following recommendations are based on Section 1613.5.1 of the 2009 International Building Code (IBC). Our scope of services did not include a seismic conditions survey to determine site-specific shear wave velocity information. IBC 2009 provides a methodology for interpretation of Standard Penetration Test resistance values (N-values) to determine a Site Class Definition. However, this method requires an averaging of N values over the top 100 feet of the subsurface profile. We note that the soil test borings for this project were extended to assigned depths of approximately 10 to 20 feet below existing site grades in order to characterize soils within the zone of influence for anticipated new foundation and pavement loads. Based upon the subsurface conditions described herein, and in accordance with section 1613.5.2 of the 2009 IBC, the subject site currently meets the conditions for a Site Classification D. The D classification is assigned for sites with a stiff soil profile where 15 bpf < the average N-value < 50 bpf. Based on a site class D determination, the geographical site location, and the mapped Maximum Considered Earthquake (MCE) ground motion for 0.2 and 1.0-second spectral response acceleration, we have estimated the following design spectral response coefficients:

Period (sec)

0.2 SS 0.230 Fa 1.600 SMS 0.368 SDS 0.246

1.0 S1 0.061 Fv 2.400 SM1 0.146 SD1 0.097

Mapped MCE Spectral

Response Acceleration (g)

Site CoefficientsAdjusted MCE

Spectral Reponse Acceleration (g)

Design Spectral Response

Acceleration (g)

The Seismic Design Category for a structure is based on the structure’s seismic use group and the design spectral response acceleration, SDS and SD1, determined in accordance with Section 1613.5.6 and the most severe seismic design category in accordance with Table 1613.5.6(1) or 1613.5.6(2). Based on the above design spectral response accelerations and the structure’s seismic use group (assumed as Use Group II), the site is assigned a Seismic Design Category B for SDS and SD1 in general accordance with the procedures outlined in Chapter 16 of the IBC 2009. The project architect and/or structural engineer should verify the above information taking into account the appropriate Seismic Use Group and other code specific requirements.

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5.7 PAVEMENT DESIGN AND RECOMMENDATIONS Assumed Traffic for Pavement Design For the purpose of evaluating the proposed pavement section, an 18-kip equivalent single axle load (ESAL) was used for the design of the travel lanes. Our evaluation assumes a daily traffic count of approximately 800 cars, 4 light dual-wheel trucks and 3 heavy tractor-trailers or other similar heavy truck traffic. Pavement Subgrade Conditions Based on the anticipated subgrade soil conditions upon completion of site preparation and proper placement of structural fill, the minimum pavement sections for flexible and rigid pavement in accordance with Dollar General Specifications can be used. The Dollar General minimum pavement sections are summarized in the following tables:

Dollar General Minimum Flexible (Asphalt) Pavement Sections

Aggregate Base Course (inches)

Asphalt Course BINDER (inches)

Asphalt Course SURFACE (inches)

Standard Duty Areas 6 1.5 1.5 9

Heavy Duty Areas 8 2 2 12

MATERIAL THICKNESS (inches)

PAVEMENT SECTION

TOTAL PAVEMENT SECTION (inches)

Dollar General Minimum Rigid (Concrete)* Pavement Sections

RIGID PAVEMENT (CONCRETE) LIGHT DUTY HEAVY DUTY

Portland Cement Conrete (4,000 psi) 5 inches 6 inches

Aggregate Base Course (ABC) 4 inches 6 inches* Concrete pavement should consist of 4,000-psi (650 psi flexural strength) air entrained Portland cement concrete overlying a properly prepared/approved soil subgrade.

EAS’S ALTERNATIVE PAVEMENT SECTIONS Based on performing Laboratory CBR Testing, the condition of the site subsurface soils, the previously assumed traffic volumes, the existing and/or planned site subgrade conditions, and ACI 330 design procedures; we recommend the following concrete pavement sections over a prepared subgrade:

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EAS Recommended Rigid (Concrete) Pavement Sections (1,2,3,4)

Rigid Pavement Material Standard Duty Areas Heavy Duty AreasPortland Cement Concrete

(4,000 psi at 28 days) 5 inches 6 inches

Aggregate Base Course 0 inches 0 inchesRecommended pavement sections assume a properly prepared and engineer-approved soil subgrade. A layer of aggregate base course may be needed for construction access during wet and/or cold seasons of the year. Therefore, we recommend the pavement contractor have a contingency budget for possible undercutting and placement of compacted aggregate base.

(1) Design based on EAS’s engineers and/or technician being retained to provide the recommended laboratory testing and observation and testing during construction. (2) Use of this design requires that a laboratory CBR test be performed prior to construction (note: test requires 5 to 7 days to perform). If the planned subgrade soils do not achieve the assumed CBR value of 8, then EAS should be retained to perform an alternate pavement design. (3) Design based on EAS’s engineers be retained to prepare a comprehensive concrete jointing plan and EAS’s engineer and/or engineering technician observation and testing during construction. 4) Design based on 4,000-psi (600 psi flexural strength) air entrained Portland cement concrete overlying a properly prepared/approved soil subgrade. All non-curbed and/or confined outside pavement edges must be thickened 2 inches to increase edge support. The store entrance apron area, dumpster pad and dumpster approach area should be a minimum 7 inches thick. Jointed concrete panels that have a length to width ratio greater than 1.25 shall include crack control reinforcement consisting of #4 rebar placed 24 inches on-center both directions at approximately 2 inches below the finished concrete surface. The crack control reinforcement should not overlap into adjacent concrete panels.

In order to use the alternative pavement section provided above a laboratory and/or field CBR verification test is required to be performed using the actual subgrade soils or planned structural fill soils to confirm that a suitable CBR value is available prior to placing the planned concrete pavements. For purposes of the concrete design we have followed the ACI 330 design procedure for jointed plain concrete pavement over a properly prepared/compacted subgrade. We recommend that a detailed concrete jointing plan be prepared for any/all planned concrete pavements. The Jointing of the concrete pavement should incorporate design guidelines in general accordance with ACI 330R-08, Section 3.7. If EAS’s engineers are not retained to prepare the concrete jointing plan, then we recommend that we are at least retained to review the final plan prior to construction.

Preparation of All Pavement Areas Pavement areas should be proofrolled and inspected as recommended within this report. Structural fill placed within pavement and drive areas should be compacted to 100 percent of the material's maximum dry density as determined by ASTM Test Method D698 within the upper eighteen inches below planned finish subgrade elevations. The asphalt aggregate base course should be compacted to least 95 percent of the material's maximum dry density as determined by ASTM Test Method D1557. Density testing should be performed at a sufficient frequency to

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verify that the fill and aggregate base course have been compacted in accordance with the guidelines of this report or project specification requirements. Proper drainage may be aided by grading the site such that surface water is directed away from pavements and by construction of swales adjacent to the pavements. All pavements should be graded such that surface water is directed towards the outer limits of the paved area or to catch basins located such that surface water does not remain on the pavement. A minimum pavement grade of 2 percent is recommended. General Asphalt and Concrete Pavement Guidelines In general, long-term pavement performance requires good drainage, performance of periodic maintenance activities, and particular attention to subgrade preparation. EAS recommends that rigid concrete pavement be used in loading dock areas, dumpster and dumpster approach areas or any other area subjected to concentrated truck loading. Flexible asphalt pavements, concrete pavements and bases should be constructed in accordance with the guidelines of the latest applicable Virginia Department of Transportation (VDOT) Specifications. Materials, weather limitations, placement and compaction are specified under appropriate sections of this publication. Concrete pavement design and construction should be in accordance with applicable American Concrete Institute (ACI) guidelines. EAS recommends that the dumpster pad and the dumpster approach area should be a minimum of 7 inches thick, 4,000 psi, air-entrained concrete. All non-curbed and/or confined outside pavement edges should be thickened 2 inches to increase edge support. The store entrance apron area should be a minimum of 7 inches thick. Jointed concrete panels that have a length to width ratio greater than 1.25 should include crack control reinforcement consisting of #4 rebar placed 24 inches on-center both directions at approximately 2 inches below the finished concrete surface. The crack control reinforcement should not overlap into adjacent concrete panels. We recommend that a detailed concrete jointing plan be prepared for any/all planned concrete pavements. The Jointing of the concrete pavement should incorporate design guidelines in general accordance with ACI 330R-08, Section 3.7. If EAS’s engineers are not retained to prepare the concrete jointing plan, then we recommend that we are at least retained to review the final plan prior to construction. Recent pavement studies by the American Concrete Pavement Association (ACPA) have indicated that jointed plain concrete pavements perform at least as well as, and usually somewhat better than, jointed reinforced concrete pavements. These studies also conclude that transverse joint spacing has a very significant effect on pavement performance. Decreasing the longitudinal joint spacing to more equally spaced transverse and longitudinal joints and square sections has the following beneficial effects:

• Decreases thermal curl stress • Decreases transverse cracking • Decreases upward curling of slab at joint • Decreases joint spalling

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• Decreases seasonal and daily joint opening (which increases joint load transfer effectiveness and reduces sealant extension)

5.8 TEMPORARY EXCAVATION RECOMMENDATIONS Mass excavations and other excavations required for construction of this project must be performed in accordance with the United States Department of Labor, Occupational Safety and Health Administration (OSHA) guidelines (29 CFR 1926, Subpart P, Excavations) or other applicable jurisdictional codes for permissible temporary side-slope ratios and/or shoring requirements. The OSHA guidelines require daily inspections of excavations, adjacent areas and protective systems by a “competent person” for evidence of situations that could result in cave-ins, indications of failure of a protective system, or other hazardous conditions. 6.0 CONSTRUCTION OBSERVATIONS AND TESTING We recommend that a review of plans and specifications with regard to foundations, and earthwork be completed by Engineering and Surveying Professionals, Inc. (EAS) prior to construction bidding. Our continued involvement on the project will aid in the proper implementation of the recommendations discussed herein. As previously discussed, the Geotechnical Engineer of record should be retained to monitor and test earthwork activities, and subgrade preparations for foundations, floor slabs and pavements. It should be noted that the actual soil conditions at the various subgrade levels and footing bearing grades will vary across this site and thus the presence of EAS’s Geotechnical Engineer and/or his representative during construction will serve to validate the subsurface conditions and recommendations presented in this report. EAS’s representative(s) should be present at the site on a part-time to full-time basis during site preparation to observe site clearing, preparation of exposed surfaces after clearing, and on a full time basis during placement, treatment and compaction of all site structural (building and parking lot) fill materials. EAS’s observations should be supplemented with periodic compaction tests to establish substantial conformance with these recommendations. Moisture content of the building pad (footings and slab subgrade) should be tested immediately prior to concrete placement. EAS should observe foundation excavations prior to placement of reinforcing steel or concrete to assess whether the actual bearing conditions are compatible with the conditions anticipated during the preparation of this report. EAS should also observe placement of all foundation, slab and or pavement concrete on a full-time basis. The following is a list of the Dollar General’s minimum inspection requirements. The site construction contractor is responsible to schedule EAS’s representative/technical staff for the testing and observation of ALL the following: 1. Pre-construction meeting (detailing scheduling, review geotechnical data, plans and specs)

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2. Site work a. Subgrade proofroll with a loaded tandem axel truck; undercut and replace unsuitable

material as required by EAS’s Geotechnical representative. b. Soil sample of proposed structural fill. The types of tests needed per sample are: Standard

Proctor (ASTM D698- maximum dry density) or Modified Proctor (ASTM D1557), Atterberg Limits (soil classification) and Moisture Content (in-situ condition). The material must meet the requirements for structural fill as specified in the geotechnical report and will be verified on site by EAS’s engineering technician.

c. Fill Density testing (full-time observation, documentation and testing): Nuclear Density Testing of each lift of compacted fill: 6” maximum compacted lifts, 1 test per 5,000 SF in building, 1 test per 10,000 SF in paved areas, or a minimum of five tests per lift throughout site. Determines percent compaction as compared to maximum dry density determined per soil sample required.

d. Utility pipe backfill density testing (full-time observation, documentation and testing): Nuclear Density Testing, a minimum of 1 test per structure, or 1 test per 100 lineal feet per 8” lift. Test results should comply with recommendation of Geotechnical Report and will be verified on site by EAS’s engineering technician.

3. Foundation Inspection

Required inspections are: Reinforcing Steel Observation (Inspect for clean, dry footing bottom; size and spacing of reinforcing steel; size and depth of footing; clearances from sides and bottom of footing) and Dynamic Cone Penetrometer Testing of Foundation Sub-grade. Test results should comply with recommendation of Geotechnical Report and will be verified on site by EAS’s engineering technician.

4. Concrete Testing Compressive Strength Testing of Concrete (full-time observation, documentation and testing): Number and frequency of tests are as follows: 1 Set of 4 Concrete Cylinders per 50 Placed Yards, Compression Testing at (1) at 7 Days, (2) at 28 Days of Curing, and (1) Hold. A minimum of 3 Sets per Project (footings, slab, dumpster pad). Test results will be verified by testing lab/EAS and provided to Dollar General Construction.

5. Structural Steel Inspection Observe all welds and bolted connections for compliance with AISC, AWS and/or metal building project specifications. Welding tolerances are determined by requiring all welds and bolted connection to adhere to AISC (American National Standards Institute/American Institute of Steel Construction) and AWS (American Welding Society) Standards. Test results should comply with recommendation of onsite structural engineering representative.

6. Floor Flatness Testing

Testing for floor flatness and floor level should reflect the following values: FF – 35, FL – 30. Floor flatness can be no lower than 30, Floor Levelness no lower than 25 for any test set grouping.

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7. Asphalt Pavement Testing a. Base course density testing and thickness measurements. b. Full-time observation, documentation and testing during placement. Coring of Asphalt

Parking Lot for thickness testing. A minimum of three cores will be required spaced evenly throughout parking area. Cores are measured for compliance with project paving profiles recommended in Geotechnical Report and bulk specific gravity tests conducted for density (minimum of 93% compaction based on design unit weight).

8. Concrete Pavement Testing

a. Base course density testing and thickness measurements. b. Compressive Strength Testing of Concrete (full-time observation, documentation and

testing): Number and frequency of tests are as follows: 1 Set of 4 Concrete Cylinders per 50 Placed Yards, Compression Testing at (1) at 7 Days, (2) at 28 Days of Curing, and (1) Hold. Approximately 3 Sets Per Project (footings, slab, dumpster pad). Test results will be verified by testing lab/EAS and provided to Dollar General Construction.

c. A detailed concrete jointing plan shall be prepared for any/all planned concrete pavements. The Jointing of the concrete pavement should incorporate design guidelines in general accordance with ACI 330R-08, Section 3.7. If EAS’s engineers are not retained to prepare the concrete jointing plan, then we recommend that EAS is retained to review the final plan prior to construction.

7.0 LIMITATIONS This report has been prepared for the exclusive use of the JR Lex, LLC for specific application to the referenced property in accordance with generally accepted soil and foundation engineering practices. No other warranty, express or implied, is made. Our conclusions and recommendations are based on design information furnished to us; the data obtained from the previously described subsurface exploration program, and generally accepted geotechnical engineering practice. The conclusions and recommendations do not reflect variations in subsurface conditions which could exist intermediate of the boring locations or in unexplored areas of the site. Should such variations become apparent during construction, it will be necessary to re-evaluate our conclusions and recommendations based upon on-site observations of the conditions. Regardless of the thoroughness of a subsurface exploration, there is the possibility that conditions between borings will differ from those at the boring locations, that conditions are not as anticipated by the designers, or that the construction process has altered the soil conditions. Therefore, experienced geotechnical engineers should evaluate earthwork, pavement, and foundation construction to verify that the conditions anticipated in design actually exist. Otherwise, we assume no responsibility for construction compliance with the design concepts, specifications, or recommendations. In the event that changes are made in the design or location of the proposed structure, the recommendations presented in the report shall not be considered valid unless the changes are

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reviewed by our firm and conclusions of this report modified and/or verified in writing. Prior to final design, EAS should be afforded the opportunity to review the site grading and layout plans to determine if additional or modified recommendations are necessary. If this report is copied or transmitted to a third party, it must be copied or transmitted in its entirety, including text, attachments, and enclosures. Interpretations based on only a part of this report may not be valid.

PROFESSIONALS, INC.

FIGURES

SITE VICINITY PLAN – FIGURE NO. 1 BORING LOCATION PLAN – FIGURE NO. 2

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APPENDIX A

KEY TO SOIL CLASSIFICATION CHART UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)

SPT BORING LOGS

KEY TO BORING LOG SOIL CLASSIFICATIONS

Soil Identification

Identification of soil type is made on the basis of an estimate of particle size

for predominantly coarse-grained soils and on the basis of cohesiveness (plasticity)

for predominantly fine-grained soils. When a soil sample consists of two or more

soil types, the percentages of the types are estimated by weight and indicated by

descriptive terminology.

Soil Descriptive

Soil Type Particle Size Component Term Percentage

Boulder >12 in. Major Uppercase Letters >50%

Cobble 3 - 12 in.

Gravel - Coarse 3/4 - 3 in. Secondary Adjective 20 - 50%

- Fine #4 - 3/4 in.

Sand - Coarse #10 - #4 Others Some 20 - 35%

- Medium #40 - #10

- Fine #200 - #40 Little 10 - 20%

Silt (non-cohesive) <#200

Clay (cohesive) <#200 Trace 0 - 10%

Notes: 1) Particle size is designated by U.S. Standard Sieve Sizes.

2) Atterberg Limit deteminations are often used to classify fine-grained soils (silts and clays).

Relative Density or Consistency

The standard penetration resistance values (N-Values) are used to describe the relative

density of coarse-grained soils or the consistency of fine-grained soils.

RELATIVE DENSITY CONSISTENCY

Term N-Value Term N-Value

Very Loose 0 - 4 Very Soft 0 - 1

Loose 5 - 10 Soft 2 - 4

Medium-Dense 11 - 30 Medium Stiff 5 - 8

Dense 31 - 50 Stiff 9 - 15

Very Dense >50 Very Stiff 16 - 30

Hard >30

Notes: 1) The N-value is the number of blows of a 140 lb. hammer freely falling 30 inches required

to drive a standard split spoon sampler (2.0 in. O.D., 1 3/8 in. I.D.) 12 inches into the soil

after properly seating the sampler into undisturbed soils.

2) Large gravel size particles are often not recovered by the standard split-spoon sampler

and therefore the true percentage of gravel is not accurately estimated.

3) When encountered, large gravel size particles often increase the N-value of the standard

penetration test.

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Documents

SUBSURFACE EXPLORATION AND GEOTECHNICAL …