REPORT OF SUBSURFACE EXPLORATION

Transcription

1 REPORT OF SUBSURFACE EXPLORATION WELDING & JOINING TECHNOLOGY FACILITY NORTH GEORGIA TECHNICAL COLLEGE CLARKESVILLE, GEORGIA S&ME PROJECT NO Prepared For: LW Engineering, P.C. Post Office Box 660 Cornelia, Georgia 01 Prepared By: S&ME, Inc. 1 Suber Road Columbia, South Carolina 910 April, 010

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3 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 TABLE OF CONTENTS EXECUTIVE SUMMARY PROJECT INFORMATION.... EXPLORATION PROCEDURES.... LABORATORY TESTING.... SITE CONDITIONS....1 Surface Conditions.... Subsurface Conditions Site Geology..... Interpreted Subsurface Profile.... BUILDING CODE SEISMIC PROVISIONS....1 IBC Site Class.... Design Spectral Values RECOMMENDATIONS Site Preparation Clearing and Grubbing Proofrolling/Densification of the Stripped Surface Fill Placement and Compaction Wet Weather Grading Settlement Due to Fill Placement Foundation Design and Construction Allowable Bearing Pressure Bearing Depth and Dimension Settlement Foundation Lateral Capacity Construction and Observation of Footings Grade Slab Support and Construction PAVEMENT DESIGN Assumed Traffic Flexible Pavements Rigid Pavements Final Examination of Soil Subgrade QUALIFICATIONS OF REPORT...1 APPENDIX Figure 1 Site Vicinity Map Figure Boring Location Plan Figure Subsurface Profile A-A Summary of Exploration Procedures Boring Logs Laboratory Data

4 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 EXECUTIVE SUMMARY The information provided in this executive summary is intended to be a brief overview of project information and recommendations from the geotechnical report. Information in the executive summary should not be used without first reading the geotechnical report and the recommendations described therein. The project site is located on Collins Hall Drive at the North Georgia Technical College campus in Clarkesville, Georgia. The subsurface exploration included eight soil test borings with Standard Penetration Test sampling and testing. Based on the provided topographic site plan, relief across the site is approximately 0 feet. Standing water was not observed at the site during our site visit. The silty sands, sandy clays and sandy silts encountered near the ground surface of our borings appear suitable for use as structural fill, provided they are free of deleterious materials. Sandy clays and sandy silts encountered in our borings will have a tendency to retain moisture. If these soils are used as structural fill, extended drying times will be required if they become wet during wet weather grading. Placement of structural fill on top of existing soils within the building footprint will result in settlement of one to two inches. Settlement monitoring is recommended for at least one week after completion of fill placement in the building pad. Assuming proper design and construction of the proposed footings, a net bearing pressure of,000 psf or less is recommended for individual spread footings bearing on natural soils similar to those encountered in our borings and on fill compacted under our observation. Soil test boring data at the site indicate IBC 006 Seismic Site Class D to be appropriate for this site. Design spectral values for the project area indicate the site to be Design Category C for Occupancy Category I, II, and III structures according to IBC

5 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, PROJECT INFORMATION Information about the project was obtained through correspondence between Luke Williams with LW Engineering and Andy Whitfield with S&ME on November, 009 and January 1, 010. It is our understanding that development at the site will include the construction of an approximate 17,000 square foot learning facility at the North Georgia Technical College (NGTC) campus in Clarkesville, Georgia. The new facility will consist of a welding lab, open air grinding area, and office space. Parking and drive areas will be located around the structure. The proposed structure will likely be a pre-engineered metal building construction supported by shallow foundations and a slab-on-grade. Column loads were provided by LW Engineering on March 0, 010, and are anticipated to be approximately 90 kips. Traffic volumes and loadings resulting in approximately 00 cars and delivery trucks per day were assumed for normal duty pavement design.. EXPLORATION PROCEDURES Boring locations were staked in the field by others prior to S&ME mobilization to the site. The field subsurface exploration was performed on March 1 th and 1 th, 010. The exploration included eight soil test borings with Standard Penetration Test (SPT) sampling and testing. Four borings were advanced in the proposed building footprint; three borings were advanced in the proposed pavement footprint, and one boring was advanced in the proposed retention pond. In addition, two bulk samples of soils that will likely comprise the subgrade were obtained from the auger cuttings of hand auger borings performed in the vicinity of boring locations B- through B-8. A summary of our exploration procedures is included in the Appendix.. LABORATORY TESTING After visual observation and manual manipulation of the soils, it was determined that the soils beneath the topsoil at the site consisted mainly of Sandy Silts (ML and MH), and Silty Sands (SM). We conducted quantitative laboratory tests consisting of: Two Standard Proctor moisture density relationship test. One soaked (one-point) California Bearing Ratio (CBR) test. Two Wash 00 grain size analysis tests. Two Wash 00 percent fines determination tests. Four Atterberg Limits tests. Two moisture content tests. The soaked laboratory California Bearing Ratio (CBR) test was also performed on a representative portion of the bulk sample compacted (remolded) to approximately 98 percent of the Standard Proctor maximum dry density near the optimum moisture content. Standard Proctor and CBR tests were used to help evaluate soil support values for floor slabs and pavement sections.

6 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010. SITE CONDITIONS S&ME s assessment of the geotechnical conditions began with a reconnaissance of the topography and physical features of the site. We also consulted available topographic and geologic maps, for relevant information..1 Surface Conditions The project site is located on Collins Hall Drive at the North Georgia Technical College campus in Clarkesville, Georgia. The site is currently an open pasture. Based on the topographic site plan provided, the site slopes from west to east away from Collins Hall Drive with relief across the site of about 0 to feet. Relief with in the proposed building footprint is approximately 1 feet. Standing water was not observed at the time of our site visit.. Subsurface Conditions Recovered field samples and field boring records were reviewed in the laboratory by the geotechnical professional. Soil test boring records and other field data are assembled in the Appendix...1 Site Geology The site lies within the Piedmont Physiographic Province of Georgia, an area underlain by soils weathered in place from the parent crystalline bedrock material. Residual soils of the Piedmont consist of stiff or very stiff micaceous silts and clays, grading to firm sands with depth. These soils have been completely weathered in place from the parent bedrock material, but below depths of a few feet retain most of the relict rock structure. Soil strength derives largely from relict intermolecular bonding and remolded materials generally less exhibit lower shear strength than do undisturbed samples. Piedmont soils are normally consolidated to slightly overconsolidated. The term partially weathered rock (PWR) is applied to very dense micaceous sands or silty sands of the Piedmont Province, which register SPT N-values in excess of 100 blows per foot. PWR generally varies widely within even small areas owing to minute differences in the chemical properties of the parent bedrock, which results in widely varying rates of weathering. Isolated lenses or seams of PWR often are present within Piedmont Residuum well above the overall PWR level within a given area. PWR is considered excellent bearing material for foundations and is relatively incompressible except in highly stressed deep foundations... Interpreted Subsurface Profile The generalized subsurface conditions at the site are described below. An interpreted subsurface cross-sectional profile of the site soils is attached as Figure. The crosssection orientation in plan view is indicated on Figure. Subsurface conditions between the borings will likely vary from those indicated on our cross-section. The nature and extent of variations between the sampling points will not become evident until construction, and stratification lines shown are not warranted. For detailed descriptions and stratification at a particular boring location, the respective boring record should be reviewed. Soil test boring logs are attached in the Appendix.

7 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 Top-of-ground elevations shown on the boring logs are assumed and were interpolated from the provided topographic site plan provided by LW Engineering for demonstration purposes only. Boring locations and elevations were not surveyed by S&ME. Topsoil Approximately to inches of topsoil was encountered at our boring locations. While these measurements are likely representative of the topsoil thicknesses that will be encountered during construction, the potential exists that greater topsoil thickness may be encountered at other locations on the site. Soils Encountered Our borings generally encountered silty sands, sandy silts and sandy clays beneath the topsoil at the site. Sandy elastic silt was encountered beneath the topsoil to depths ranging from -1/ to 6 feet below the ground surface in borings B-1, B- and B-8. These soils were generally reddish-brown in color and were moist with mostly medium plasticity fines and some fine sands. Standard Penetration Test (SPT) N-values recorded in sandy elastic silts ranged from 7 to 1 blows per foot, indicating a firm to stiff consistency. Sandy silt was encountered from a depth of about -1/ feet to -1/ feet in boring B-1, and from 6 feet to 1-1/ feet in boring B-8. These soils were generally brown, reddishbrown and purple in color and were moist with mostly low to medium plasticity fines and some fine to medium sands. SPT N-values recorded in these layers ranged from 9 to 18 blows per foot, indicating a stiff to very stiff consistency. Sandy lean clay was encountered in the upper to feet of borings B- through B-7. These soils were generally red and white in color with mostly low to medium plasticity fines, and some fine to medium sands. SPT N-values recorded in sandy clays ranged from 6 to 11 blows per foot, indicating a firm to stiff consistency. Silty sands were encountered in all borings at the site with the exception of boring B-7. These soils were generally orange, gray, brown or white in color and were moist with mostly fine to medium sands and some low to medium plasticity fines. Fine to medium quartz gravel were observed in silty sands encountered in borings B- and B-6. SPT N- values recorded in silty sands ranged from to 6 blows per foot, indicating a very loose to medium dense relative density. Silty sands were generally medium dense throughout; however, very loose to loose sands were encountered in borings B- and B- Ground Water Groundwater was not encountered in any of our borings at the time of drilling. Due to the nature of the soils encountered in the upper ten feet of the borings it is possible that perched seams or lenses of water may occur. These seams or lenses of perched water generally occur on layers of stiff silts or medium dense sands during wet periods. We note that groundwater levels are influenced by precipitation, long term climatic variations, and nearby construction. Groundwater measurements made at different times

8 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 than our exploration may indicate groundwater levels substantially different than indicated on the boring records in the Appendix.. BUILDING CODE SEISMIC PROVISIONS Seismic induced ground shaking at the foundation is the effect taken into account by building code seismic-resistant design provisions. The following paragraphs include seismic site classification and seismic design category information about the site, and process for determining these parameters according to the International Building Code, 006 Edition..1 IBC Site Class We classified the site as one of the Site Classes defined in IBC Section 161 (Table 161..) using the procedures described in Section The Site Class is used in conjunction with mapped spectral accelerations S S and S 1 to determine Site Coefficients F A and F V in IBC Section 161.., tables 161..(1) and 161..(). Determining Site Class involves several steps. The initial step in site class definition is a check for the four conditions described for Site Class F which would require a site specific evaluation to determine site coefficients F A and F V. Site Class F as defined in Section 161 includes sites with soils under any of the following conditions: 1. Soils vulnerable to potential failure including quick and highly sensitive clays or collapsible weakly cemented soils;. peats and highly organic clays;. very high plasticity clays; and,. very thick soft/medium stiff clays. Boring data available at this site extend to auger refusal at 8 feet. None of the conditions described in items 1 above pertaining to Site Class F were evident in the soil test borings performed. Based on the soil test boring data and knowledge of the general geologic profile of this area, Site Class D appears to generally represent conditions in and around the site.. Design Spectral Values S&ME determined the spectral response parameters for the site using the general procedures outlined under the 006 International Building Code Section This approach utilizes a mapped acceleration response spectrum corresponding to an earthquake having a percent statistical probability of exceedance in 0 years to determine the spectral response acceleration at the top of seismic bedrock for any period. The Site Class is used in conjunction with mapped spectral accelerations S S and S 1 to determine Site Coefficients F A and F V in IBC Section 161.., tables 161..(1) and 161..(). For purposes of computation, the Code includes mapped induced acceleration at frequencies of hertz (S S ) and 1 hertz (S 1 ), which are then used to derive the remainder of the response spectra at all other frequencies. Mapped S S and S 1 values represent motion at the top of bedrock. The surface ground motion response spectrum, accounting for inertial effects within the soil column overlying rock, is then determined

9 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 for the design earthquake using spectral coefficients F A and F V for the appropriate Site Class. The design ground motion at any period is taken as / of the smoothed spectral acceleration as allowed in section The design spectral response acceleration values at short periods S DS and at one second periods S D1 are tabulated below for the unimproved soil profile. Peak ground acceleration (PGA) was obtained by dividing the S DS value by.. Table 1: Design Spectral Values Value S DS S D1 PGA 006 International Building Code 0.9 g 0.18 g 0.16 g Design spectral values for the project area indicate the site to be Design Category C for Occupancy Category I, II, and III structures according to IBC RECOMMENDATIONS The following paragraphs include our conclusions and recommendations for site preparation, fill placement and compaction, and design and construction of foundations. The soil profile encountered at this site appears generally suitable for the proposed development. 6.1 Site Preparation Grading and subgrade preparation will vary somewhat between cut and fill areas. Below are recommendations for preparation of the site prior to fill placement and compaction Clearing and Grubbing Strip and grub all vegetation and topsoil in the building footprint and pavement areas and dispose of this material outside of the building footprint and pavement areas. Large stumps and tree root bulbs should be completely removed Proofrolling/Densification of the Stripped Surface After stripping and cutting to grade, cut areas and areas that will receive less than 1 inches of new fill should be surface rolled to compact the upper 1 inches of existing soils to at least 98 percent of standard Proctor maximum dry density. In areas that will receive more than 1 inches of new fill the exposed surface should first be proofrolled using a heavily loaded truck or pan to identify soft areas. Areas which rut or pump excessively under the proofrolling operation will need to be stabilized prior to placement of new fill soil, base course layers or slabs. Soft, wet or unstable soils may make it difficult to achieve the required compaction and will exhibit substantially lower bearing for floor slabs, foundations, or pavements. Stabilization, if 6

10 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 required, may consist of scarifying and/or drying and re-compacting any soft or wet surface soils or removing and replacing unstable material. Additional stabilization may be required if surface soils are heavily reworked or allowed to become saturated during construction. 6. Fill Placement and Compaction Sandy silts (ML) and silty sands (SM) similar to those encountered near the ground surface of our borings are suitable for use as structural fill, provided they are free of deleterious materials. These soils will have a tendency to retain moisture. If these soils are used as structural fill, extended drying times may be required during wet weather grading. Sandy elastic silt (MH) soils similar to those encountered in the upper strata of borings B- and B- through B-7 should be avoided for use as structural fill. All fill placed in building, pavement, and embankment areas should be comprised of soils free of organic matter and other deleterious materials. The fill should be uniformly spread in relatively thin lifts (8 inches, loose) and compacted to at least 98 percent of the soil s maximum dry density as determined by a laboratory standard Proctor compaction test (ASTM D-698). The moisture content should be controlled to within plus to minus percent of optimum. In addition to meeting the compaction requirement, fill material should be stable under movement of the construction equipment and should not exhibit rutting or pumping. It is very important that all fill is uniformly well compacted. Accordingly, fill placement should be monitored by a qualified Materials Technician working under the direction of the Geotechnical Engineer. In addition to this visual evaluation, the Technician should perform at least one in-place density test for each 000 square feet per lift in mass grading and one density test per 0 feet in utility line trenches Wet Weather Grading Based on our experience, sandy silts and silty sands similar to those encountered in the upper strata of our borings will be difficult to work if allowed to become wet. These soils may also require extended drying times once wet. If these soils are used as structural fill, to help reduce the potential for these soils becoming wet during rain events, we recommend the surface be sealed with a smooth drum roller if rain is pending. The grading contractor should try to maintain positive drainage from the site throughout the grading activities. 6. Settlement Due to Fill Placement Based on the grading plan provided, up to eight feet of fill will be placed in the north and east portions of the building pad. The additional weight of the surcharge load will cause some compression of the existing soils. The following table assumes fill consisting of material similar to the silty sands, sandy clays, and sandy silts encountered in our borings, and a compacted unit weight of approximately 10 pcf and near the optimum moisture content. 7

11 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 Table : Estimated Settlement Due to Fill Placement on Existing Soils Boring Location Estimated Fill Height Estimated Applied Area Load Estimated Settlement* B- ½ feet B- 7 ½ feet 0 psf 1 inch 900 psf inches * Settlement values do not include anticipated settlement at footing locations due to column loads. It is likely that some of the settlement will be complete in the silty sand strata during fill placement. However, layers of sandy elastic silt similar to those encountered in the upper 6 feet at boring location B- will likely require additional time for settlement to occur after completion of fill placement. Prior to placing foundations, we recommend settlement monitoring in the building pad for at least one week after completion of fill placement. Settlement monitoring may be performed by driving a rebar stakes into the completed fill at two to three locations in the building pad. Rebar stakes should be protected from disturbance by construction equipment. The top of rebar elevation should be surveyed daily for at least one week. The surveyed elevations for each location should be provided to the Geotechnical Engineer to determine when settlement has substantially ended. Foundation placement should not start in the deeper fill areas until settlement due to the fill placement has substantially ended. 6. Foundation Design and Construction Shallow foundations appear suitable for use on the proposed project at this site. We estimated bearing capacities for typical footing configurations and dimensions using our boring data and our experience with similar soils under similar loading conditions. Estimated ultimate bearing capacity exceeds recommended allowable bearing pressures by a safety factor of at least under static conditions, provided that footings are designed and constructed as outlined in this report Allowable Bearing Pressure Assuming proper design and construction of the proposed footings, a net bearing pressure of,000 psf or less is recommended for individual spread footings bearing on natural soils similar to those encountered in our borings and on fill compacted under our observation. Footing excavations should be examined by the geotechnical engineer or representative of the geotechnical engineer prior to placement of concrete to determine that variations in the soil do not lower the allowable bearing capacity. It may be necessary to redesign footings in the field (e.g. widen or deepen footings) based on observed conditions. 6.. Bearing Depth and Dimension Minimum individual spread footing and wall footing widths should be at least and 18 inches, respectively, with a minimum embedment depth of 1 inches below final grade. 8

12 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, Settlement Assuming a foot by 6 foot spread footing supporting a column load of 90 kips and bearing on existing soils or well compacted fill, estimated total settlements are approximately one inch. Differential settlements between adjacent footings with similar loads are estimated to be about one half the total settlement values or approximately onehalf inch. Estimated settlements provided assume footings are constructed as recommended elsewhere in this report. These values assume the footings are properly designed and constructed and that footing excavation bottoms are compacted prior to placement of concrete. These values also assume that settlements due to the weight of newly placed fill have substantially ended prior to placing foundations. 6.. Foundation Lateral Capacity Lateral capacity of footings includes a soil lateral pressure and coefficient of friction as described in IBC Section 180. Footings will be embedded in material similar to those described as Class as described in Table Where footings are cast neat against the sides of excavations in natural soils, an allowable lateral bearing pressure of 100 psf per foot depth below natural grade may be used in computations. Lateral sliding resistance can be calculated by multiplying a resistance value of 10 psf by the contact area. An increase of one-third in the allowable lateral capacity may be considered for load combinations, including wind or earthquake, unless otherwise restricted by design code provisions. 6.. Construction and Observation of Footings When possible concrete should be placed the same day footings are excavated to grade. Remove soils softened by water intrusion or exposure before placing concrete. The geotechnical engineer or a representative of the geotechnical engineer should observe cleaned footing excavations prior to concrete placement. S&ME should also observe undercut areas prior to backfilling to confirm that poor soils have been removed and that the exposed subgrade is suitable for support of footings or backfill. 6. Grade Slab Support and Construction After cut operations and fill placement are completed to achieve subgrade elevation for the building pad, the exposed surface should be proofrolled under the supervision of the geotechnical engineer with a heavily loaded dump truck or pan. Areas of rutting or pumping soils may require selective undercutting or further stabilization prior to placement of the slab. The silty sands, sandy clays, and sandy silts (ML) penetrated by our borings or wellcompacted fill will provide adequate support to proposed soil-supported grade slabs, assuming preparation and compaction of the subgrade as recommended in this report. A modulus of subgrade reaction (k) of 1 psi/in may be used for reinforcing design, assuming a subgrade consisting of compacted soils without segregation by composition. This value is based on published correlations between the type and condition of the fill to be placed at this site and small-diameter plate load tests. The modulus value is considered appropriate for point loads and small-diameter wheel loads, but must be modified (reduced) 9

13 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 for wide area loads. Provide joints in slabs around columns and along wall footings to accommodate minor differential settlements. Place a blanket of at least inches of compacted granular soils below slabs to provide a capillary break between the subgrade and the slab concrete. Soil used as capillary break material should contain percent or less of fines passing the No. 00 sieve. A vapor barrier such as "Visqueen," or the equivalent, is advised for placement beneath the slab to limit moisture infiltration into the finished space. 7. PAVEMENT DESIGN We conducted one California Bearing Ratio (CBR) test on subgrade soils obtained from a composite sample of the auger cuttings of a hand auger borings completed near boring locations B- through B-8. Based on the laboratory test results and considering the total soil profile affected by wheel loads, a CBR value of percent is recommended for use in design of the pavement section. This is assuming that the upper 1 inches of subgrade material is compacted to at least 98 percent of the standard Proctor maximum dry density. This also assumes that any fill material placed within the proposed pavement area is placed and compacted according to the recommendations given in this report. Imported fill should be tested to determine that it exhibits a CBR of at least percent. Design procedures are based on the AASHTO Guide for Design of Pavement Structures and associated literature. Based on the subsurface conditions and assuming our grading recommendations will be implemented as specified, the following presents our recommendations regarding typical pavement sections and materials. Our pavement analysis was performed using DARWin Pavement Design and Analysis System software. DARWin uses the AASHTO 9 Flexible Pavement Design Method for analysis of the unreinforced pavement section. Structural design DARWin input data included an initial serviceability of., a terminal serviceability of., a reliability level of 7 percent, and an overall standard deviation of 0. for flexible pavements and 0.9 for rigid pavements. 7.1 Assumed Traffic Traffic volumes were not made available as of the writing of this report, therefore assumed traffic volumes have been used in analysis and are not guaranteed to represent the actual traffic volumes. If actual traffic volumes differ from those assumed, the pavement section should be reevaluated. Traffic volumes were based on the following assumptions: A design life of 0 years with 0,000 Equivalent Single Axle Loads (ESALs) over the design life. Average Daily Traffic of 00 passenger cars per day with ESALs per vehicle (six days per week). Three medium-size delivery trucks per day with ESALs per truck (five days per week). One garbage truck per week with. ESALs per truck. 10

14 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, Flexible Pavements It is our opinion that the flexible pavement should consist of a wearing course of hot mix asphaltic (HMA) concrete and a base course of graded aggregate material. Graded aggregate material is necessary for structural support and to help transport any rainwater that seeps below the pavement. The results of our design are summarized in the following table. Table : Recommended Flexible Pavement Section Thicknesses Design Life ESAL (0 Years) Graded Aggregate Base Course Asphalt Surface Course Normal Duty 0,000 ESALs 6 in. in. Pavement materials should conform with and be placed in accordance with the Georgia Department of Transporation 007 Standard Specifications for Highway Construction for Hot Mix Asphaltic Concrete The aggregate base course should consist of readily available graded aggregate (Refer to Georgia Department of Transportation Standard Specifications for Highway Construction 007 Edition). To confirm that the base course has been uniformly compacted, in-place field density tests should be performed by a qualified Materials Technician, and the area should be methodically proofrolled under his evaluation. Although our analysis was based on a 0 year design life, our experience indicates that an overlay may be needed in approximately 7 to 10 years due to normal weathering of the asphaltic concrete. Also, some areas could require repair in a shorter time period. 7. Rigid Pavements We recommend that rigid pavement be used in areas of dumpster pads, and in front of dumpster areas to help resist the damage caused by traffic with heavy static loads. We suggest the rigid pavement extend in front of dumpster pad such that the front tires of the trash truck are resting on the pad during unloading of the dumpster. A rigid pavement design based on the traffic volumes presented above was performed. The compressive strength of the concrete was assumed to be,000 psi. Based on empirical relationships with CBR values and our past experience, a modulus of subgrade reaction of 1 pci was used for design. We recommend a rigid pavement section for the dumpster pad and service area of 6 inches of Portland Cement Concrete underlain by 6 inches of crushed stone base. The graded aggregate base course layer will help provide additional support, provide drainage and will help with the long-term performance of the concrete pavements when subjected to freeze-thaw actions. Rigid pavements should be designed and constructed in accordance with the appropriate American Concrete Institute (ACI) recommendations and with the applicable specifications of the Georgia Department of Transportation Standard Specifications for Highway Construction (007 Edition). 11

15 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, Final Examination of Soil Subgrade Pavement performance is very dependent on subgrade condition. Drainage will have a major impact on subgrade condition. Drainage should be designed to result in subsurface water levels being at least feet below the top of the pavement subgrade. Design should not result in water standing on the pavement surface or behind curbing. Design should result in positive drainage being available from the stone base material. Pavement performance will be influenced by a number of factors including the actual condition of subgrade soils at the time of pavement installation, installed thicknesses and compaction, and drainage. The subgrade soils should be reevaluated by proofrolling immediately prior to placement of base course stone and any unstable areas repaired. If, during site grading or during the final examination of the subgrade soil, the material encountered varies from the sandy silts tested the soils encountered should be observed by the geotechnical engineer and additional recommendations provided. This recommendation is very important to the long-term performance of the pavements and slabs. Areas adjacent to pavements (embankments, landscaped island, ditching, etc.) which can drain water (rainwater or sprinklers) should be designed so that water does not seep below the pavements. This may require the use of French drains or swales. Sufficient tests and inspections should be performed during pavement installation to confirm that the required thickness, density, and quality requirements of the specifications are followed. 8. QUALIFICATIONS OF REPORT This report has been prepared in accordance with generally accepted geotechnical engineering practice for specific application to this project. The conclusions and recommendations contained in this report were based on the applicable standards of our profession at the time this report was prepared. No other warranty, express or implied is made. The analyses and recommendations submitted herein are based, in part, upon the data obtained from the subsurface exploration. The nature and extent of variations between the borings will not become evident until construction. If variations appear evident, then we will re-evaluate the recommendations of this report. In the event that any changes in the nature, design, or location of the proposed structure are planned, the conclusions and recommendations contained in this report will not be considered valid unless the changes are reviewed and conclusions modified or verified in writing. Under Section 170 of the International Building Code, a formal Quality Assurance Plan is required for most structures described as Seismic Design Category D as defined in Section While some of the Special Inspections required under sections involve soils or foundations, preparation of the Quality Assurance Plan was beyond the scope of this report. 1

16 Report of Subsurface Exploration S&ME Project No Welding and Joining Technology Facility, NGTC, Clarkesville, GA April, 010 We recommend that S&ME, Inc. be provided the opportunity to review the final design plans and specifications in order to ensure that earthwork and foundation recommendations are properly interpreted and implemented. 1

17 APPENDIX

18 Project Location SOURCE: Google Maps SCALE: CHECKED BY: DRAWN BY: DATE: NTS JTP MQ //10 JOB NO. SITE VICINITY MAP NGTC Welding and Joining Technology Facility FIGURE NO: 1 Clarkesville, Georgia

19 A' B- B-7 B- FILL B- B-6 CUT B-1 A B-8 B- SOURCE: LW Engineering, P.C. APPROXIMATE BORING LOCATION DRAWING: Site Grading Plan SCALE: NTS BORING LOCATION PLAN CHECKED BY: JTP NGTC Welding and Joining Technology Facility DRAWN BY: MQ Clarkesville, Georgia DATE: //010 JOB NO FIGURE NO.

20 A A' 1,70 B-1 /1/010 1,70 1,6 0 ELEV.16 Approximate Ground Surface 1,6 ELEVATION (feet-msl) 1,60 1, 1,0 1, SANDY ELASTIC SILT (MH) SILTY SAND (SM) 0 10 B- /1/010 ELEV Topsoil SILTY SAND (SM) SANDY ELASTIC SILT (MH) B- /1/010 ELEV FFE = 161. feet 1,60 1, ELEVATION (feet-msl) 1,0 1, 1, /" ,0 1, SANDY SILT (ML) 0 0 PARTIALLY WEATHERED ROCK (PWR) SAMPLED AS SILTY SAND (SM) , ,0 1,0 1, 8. 0/0"-- SILTY SAND (SM) 1, Water Level at Time of Boring Water Level after Hours Hole Caved Water Loss/Inflow 0 SOIL TEST BORINGS B- Boring Number 1.0 Elevation at GS Standard Penetration Test (blows per foot). 1in Undisturbed Sample Recovery in Inches NX Core Barrel Size REC 80% Recovery in Percent RQD 6% Rock Quality Designation BT Boring Termination Depth AR Auger Refusal LEGEND OF MATERIAL GRAPHICS for SOIL TEST BORINGS Topsoil Sandy Silt MH, High Plasticity Silt Partially Weathered Rock SM, Silty Sand The depicted stratigraphy is shown for illustrative purposes only and is not warranted. Separations between different strata may be gradual and likely vary considerably from those shown. Profiles between nearby borings have been estimated using reasonable engineering care and judgment. The actual subsurface conditions will vary between boring locations. FIGURE SUBSURFACE PROFILE A-A' NGTC Welding and Joining Technology Facility Clarkesville, Georgia JOB NO: DATE: /0/10

21 SUMMARY OF EXPLORATION PROCEDURES Layout and Access to Boring Locations Layout Plan S&ME was provided with a scaled sketch of the site indicating the location of the proposed building and pavement footprints prior to mobilization to the site. Staking of Borings Borings were surveyed and marked in the field by others prior to S&ME mobilization to the site. Boring locations indicated on the attached Boring Location Plan must be considered as approximate. Boring and Sampling Soil Test Boring with Hollow-Stem Auger Soil sampling and penetration testing were performed in general accordance with ASTM D186, Standard Test Method for Penetration Test and Split Barrel Sampling of Soils. At regular intervals, soil samples were obtained with a standard 1. inch I.D., two-inch O.D., split barrel sampler. The sampler was first seated six inches to penetrate any loose cuttings, and then driven an additional 1 inches with blows of a 10-pound hammer falling approximately 0 inches. The number of hammer blows required to drive the sampler through the two final six inch increments was recorded as the penetration resistance (SPT N) value. The N-value, when properly interpreted by qualified professional staff, is an index of the soil strength and foundation support capability. Borehole Closure Following collection of relevant geotechnical data, boreholes were filled by slowly pouring auger cuttings into the open hole such that minimal bridging of the material occurred in the hole. Backfilling of the upper two feet of each hole was tamped as heavily as possible with a shovel handle or other hand held equipment, and the backfill crowned to direct rainfall away on the surface. Laboratory Testing Recovered disturbed and undisturbed samples and the drillers field logs were transported to the laboratory where they were examined by the geotechnical engineer. Selected samples representative of certain groups of soils were subjected to simple classification tests by hand or other simple means. Other samples were tested in the laboratory to determine their strength or classification. Examination of Recovered Soil Samples Soil samples and field boring records were reviewed in the laboratory by the geotechnical engineer. Soils were classified in general accordance with the visual-manual method described in ASTM D 88, Standard Practice for Description and Identification of Soils (Visual-Manual Method). The geotechnical engineer also prepared the final boring records enclosed with this report. Moisture Content Testing of Soil Samples by Oven Drying Moisture content was determined in general conformance with the methods outlined in ASTM D 16,

22 Summary of Exploration Procedures (continued) Standard Test Method for Laboratory Determination of Water (Moisture) Content of Soil or Rock by Mass. Liquid and Plastic Limits Testing Atterberg limits of the soils was determined generally following the methods described by ASTM D 18, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils. In current engineering usage, the liquid limit of a soil is defined as the moisture content, in percent, marking the upper limit of viscous flow and the boundary with a semi-liquid state. The plastic limit defines the lower limit of plastic behavior, above which a soil behaves plastically below which it retains its shape upon drying. The plasticity index (PI) is the range of water content over which a soil behaves plastically. Numerically, the PI is the difference between liquid limit and plastic limit values. Percent Fines Determination of Samples A selected specimen of soils was washed over a No. 00 sieve after being thoroughly mixed and dried. This test was conducted in general accordance with ASTM D 110, Standard Test Method for Amount of Material Finer Than the No. 00 Sieve. Compaction Tests of Soils Using Standard Effort Soil placed as engineering fill is compacted to a dense state to obtain satisfactory engineering properties. Laboratory compaction tests provide the basis for determining the percent compaction and water content needed to achieve the required engineering properties, and for controlling construction to assure the required compaction and water contents are achieved. Test procedures generally followed those described by ASTM D 698, Standard Test Method for Laboratory Compaction Characteristics of Soil Using Standard Effort (1,00 lbf/ft ). Laboratory California Bearing Ratio Tests of Compacted Samples This method is used to evaluate the potential strength of subgrade, subbase, and base course material, including recycled materials, for use in roadway pavements. Laboratory CBR tests were run in general accordance with the procedures laid out in ASTM D 188, Standard Test Method for CBR (California Bearing Ratio) of Laboratory Compacted Soils.

23 LEGEND TO SOIL CLASSIFICATION AND SYMBOLS SOIL TYPES (Shown in Graphic Log) Fill Asphalt Concrete Topsoil Gravel Sand Silt Clay Organic Silty Sand Clayey Sand Sandy Silt Clayey Silt Sandy Clay Silty Clay Partially Weathered Rock Cored Rock RELATIVE DENSITY Very Loose Loose Medium Dense Dense Very Dense Standard Penetration Resistance CONSISTENCY OF COHESIVE SOILS CONSISTENCY Very Soft Soft Firm Stiff Very Stiff Hard Very Hard REC SAMPLER TYPES Shelby Tube Split Spoon Rock Core No Recovery TERMS STD. PENETRATION RESISTANCE BLOWS/FOOT 0 to to to 8 9 to 1 16 to 0 1 to 0 Over 0 RELATIVE DENSITY OF COHESIONLESS SOILS (Shown in Samples Column) STD. PENETRATION RESISTANCE BLOWS/FOOT 0 to to to 0 1 to 0 Over 0 - The Number of Blows of 10 lb. Hammer Falling 0 in. Required to Drive 1. in. I.D. Split Spoon Sampler 1 Foot. As Specified in ASTM D Total Length of Rock Recovered in the Core Barrel Divided by the Total Length of the Core Run Times 100%. HC WATER LEVELS (Shown in Water Level Column) = Water Level At Termination of Boring = Water Level Taken After Hours = Loss of Drilling Water = Hole Cave RQD - Total Length of Sound Rock Segments Recovered that are Longer Than or Equal to " (mechanical breaks excluded) Divided by the Total Length of the Core Run Times 100%.

24 PROJECT: DATE DRILLED: /1/10 DRILL RIG: ATV DRILLER: S&ME - Spartanburg HAMMER TYPE: DEPTH (feet) GRAPHIC LOG NGTC Welding and Joining Technology Facility Clarkesville, GA SAMPLING METHOD: Split spoon DRILLING METHOD: ¼" H.S.A. S&ME Project No ELEVATION: 16.0 ft BORING DEPTH: 8. ft LOGGED BY: MQ MATERIAL DESCRIPTION TOPSOIL - Approximately inches of topsoil. SANDY ELASTIC SILT (MH) - mostly medium plasticity fines, little fine sands, micaceous, moist, reddish-brown, stiff. WATER LEVEL: Not encountered. WATER LEVEL ELEVATION (feet-msl) SAMPLE NO. 1 SAMPLE TYPE 1st 6in / RUN # BORING LOG: BLOW COUNT / CORE DATA 7 B-1 NOTES: Ground surface elevations are estimated from the site grading plan provided by LW Engineering. Boring locations and elevations were not surveyeyd by S&ME. NORTHING: nd 6in / REC rd 6in / RQD PL EASTING: SPT N-Value (bpf) FINES % NM LL N VALUE 11 SILTY SAND (SM) - mostly fine to medium sands, some low to medium plasticity fines, micaceous, moist, orange, gray, brown, medium dense Brown, black, red S&ME BORING LOG - VOGTLE NGTC WELDING LOGS.GPJ S&ME 009_09_.GDT // Orangish-brown Orangish-brown, trace of black. SANDY SILT (ML) - mostly low to medium plasticity fines, some fine sands, slightly micaceous, moist, brown, very stiff Brown, purple, stiff NOTES: 1. THIS LOG IS ONLY A PORTION OF A REPORT PREPARED FOR THE NAMED PROJECT AND MUST ONLY BE USED TOGETHER WITH THAT REPORT. Page 1 of. BORING, SAMPLING AND PENETRATION TEST DATA IN GENERAL ACCORDANCE WITH ASTM D STRATIFICATION AND GROUNDWATER DEPTHS ARE NOT EXACT.. WATER LEVEL IS AT TIME OF EXPLORATION AND WILL VARY.

25 PROJECT: DATE DRILLED: /1/10 DRILL RIG: ATV DRILLER: S&ME - Spartanburg HAMMER TYPE: DEPTH (feet) GRAPHIC LOG NGTC Welding and Joining Technology Facility Clarkesville, GA SAMPLING METHOD: Split spoon DRILLING METHOD: ¼" H.S.A. S&ME Project No ELEVATION: 16.0 ft BORING DEPTH: 8. ft LOGGED BY: MQ MATERIAL DESCRIPTION WATER LEVEL: Not encountered. SANDY SILT (ML) - mostly low to medium plasticity fines, some fine sands, slightly micaceous, moist, brown, very stiff. (continued) WATER LEVEL ELEVATION (feet-msl) SAMPLE NO. SAMPLE TYPE BLOW COUNT / CORE DATA 1st 6in / RUN # BORING LOG: B-1 NOTES: Ground surface elevations are estimated from the site grading plan provided by LW Engineering. Boring locations and elevations were not surveyeyd by S&ME. NORTHING: nd 6in / REC rd 6in / RQD PL EASTING: SPT N-Value (bpf) FINES % NM LL N VALUE SILTY SAND (SM) - mostly fine to medium sands, some low plasticity fines, micaceous, moist, gray, brown, trace of black, loose Boring terminated at 8. feet due to equipment refusal 10 0/0" >> 0/0" S&ME BORING LOG - VOGTLE NGTC WELDING LOGS.GPJ S&ME 009_09_.GDT //10 NOTES: THIS LOG IS ONLY A PORTION OF A REPORT PREPARED FOR THE NAMED PROJECT AND MUST ONLY BE USED TOGETHER WITH THAT REPORT. BORING, SAMPLING AND PENETRATION TEST DATA IN GENERAL ACCORDANCE WITH ASTM D-186. STRATIFICATION AND GROUNDWATER DEPTHS ARE NOT EXACT. WATER LEVEL IS AT TIME OF EXPLORATION AND WILL VARY. Page of

26 PROJECT: DATE DRILLED: /1/10 DRILL RIG: ATV DRILLER: S&ME - Spartanburg HAMMER TYPE: DEPTH (feet) GRAPHIC LOG NGTC Welding and Joining Technology Facility Clarkesville, GA SAMPLING METHOD: Split spoon DRILLING METHOD: ¼" H.S.A. S&ME Project No ELEVATION: 16.0 ft BORING DEPTH: 0.0 ft LOGGED BY: MQ MATERIAL DESCRIPTION TOPSOIL - Approximately inches of topsoil. SANDY LEAN CLAY (CL) - mostly medium plasticity fines, some fine to medium sands, moist, red, firm. WATER LEVEL: Not encountered. WATER LEVEL ELEVATION (feet-msl) SAMPLE NO. 1 SAMPLE TYPE 1st 6in / RUN # BORING LOG: BLOW COUNT / CORE DATA B- NOTES: Ground surface elevations are estimated from the site grading plan provided by LW Engineering. Boring locations and elevations were not surveyeyd by S&ME. NORTHING: nd 6in / REC rd 6in / RQD PL EASTING: SPT N-Value (bpf) FINES % NM LL N VALUE SILTY SAND (SM) - mostly fine to medium sands, some low plasticity fines, micaceous, moist, yellowish-brown, gray, loose Mostly medium to coarse sands, gray, black, brown, medium dense S&ME BORING LOG - VOGTLE NGTC WELDING LOGS.GPJ S&ME 009_09_.GDT // Mostly fine to medium sands, gray, white, black, loose. PARTIALLY WEATHERED ROCK sampled as SILTY SAND (SM) - mostly fine to medium sands, some low plasticity fines, moist, gray, white, trace of black, very dense. Boring terminated at 0 feet /" >> 6 0/" NOTES: THIS LOG IS ONLY A PORTION OF A REPORT PREPARED FOR THE NAMED PROJECT AND MUST ONLY BE USED TOGETHER WITH THAT REPORT. BORING, SAMPLING AND PENETRATION TEST DATA IN GENERAL ACCORDANCE WITH ASTM D-186. STRATIFICATION AND GROUNDWATER DEPTHS ARE NOT EXACT. WATER LEVEL IS AT TIME OF EXPLORATION AND WILL VARY. Page 1 of 1

27 PROJECT: DATE DRILLED: /1/10 DRILL RIG: ATV DRILLER: S&ME - Spartanburg HAMMER TYPE: DEPTH (feet) GRAPHIC LOG NGTC Welding and Joining Technology Facility Clarkesville, GA SAMPLING METHOD: Split spoon DRILLING METHOD: ¼" H.S.A. S&ME Project No ELEVATION: 1.0 ft BORING DEPTH: 0.0 ft LOGGED BY: MQ MATERIAL DESCRIPTION TOPSOIL - Approximately inches of topsoil. SANDY ELASTIC SILT (MH) - mostly medium plasticity fines, few fine sands, slightly micaceous, moist, red, firm. WATER LEVEL: Not encountered. WATER LEVEL ELEVATION (feet-msl) SAMPLE NO. 1 SAMPLE TYPE 1st 6in / RUN # BORING LOG: BLOW COUNT / CORE DATA B- NOTES: Ground surface elevations are estimated from the site grading plan provided by LW Engineering. Boring locations and elevations were not surveyeyd by S&ME. NORTHING: nd 6in / REC rd 6in / RQD PL EASTING: SPT N-Value (bpf) FINES % NM LL N VALUE Stiff SILTY SAND (SM) - mostly fine to medium sands, some low plasticity fines, moist, brown, orange, white, loose S&ME BORING LOG - VOGTLE NGTC WELDING LOGS.GPJ S&ME 009_09_.GDT // Slightly micaceous, gray, white, trace of brown. Boring terminated at 0 feet NOTES: THIS LOG IS ONLY A PORTION OF A REPORT PREPARED FOR THE NAMED PROJECT AND MUST ONLY BE USED TOGETHER WITH THAT REPORT. BORING, SAMPLING AND PENETRATION TEST DATA IN GENERAL ACCORDANCE WITH ASTM D-186. STRATIFICATION AND GROUNDWATER DEPTHS ARE NOT EXACT. WATER LEVEL IS AT TIME OF EXPLORATION AND WILL VARY. Page 1 of 1