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36 PRELIMINARY GEOTECHNICAL EXPLORATION Additional MeadWestvaco Ridgeville Property 331 acres Dorchester County, South Carolina S&ME Project No A Prepared For: BP Barber & Associates Post Office Box 1116 Columbia, South Carolina Prepared By: 620 Wando Park Boulevard Mt. Pleasant, South Carolina October 23, 2009

37 October 23, 2009 BP Barber & Associates Post Office Box 1116 Columbia, South Carolina Attention: Reference: Mr. Brad Sanderson, P.E. PRELIMINARY GEOTECHNICAL EXPLORATION Additional MeadWestvaco Ridgeville Property 331 Acres Dorchester County, South Carolina S&ME Project No A Dear Mr. Sanderson: We have completed our Preliminary Geotechnical Exploration of the additional 331 acres of MeadWestvaco (MWV) Ridgeville property in Dorchester County, South Carolina. Our services were performed in general accordance with S&ME proposal No B dated October 12, The purpose of our Preliminary Geotechnical Exploration was to determine the general site subsurface conditions at widely-spaced locations, and then to evaluate the major impacts these conditions will have on site development. This report presents our understanding of the project, the site and subsurface conditions we encountered, and our preliminary conclusions and recommendations. PROJECT INFORMATION The project site consists of approximately 331 acres along US Highway 78 near Ridgeville in Dorchester County, South Carolina. This site is bordered to the south by additional MWV property. We recently performed a preliminary geotechnical exploration 1 for this adjacent property. We understand development plans are preliminary at this time, and the purpose of this work is for site certification with the South Carolina Department of Commerce. As a basis for our preliminary analyses, we assume site development will be industrial. Therefore, we assume maximum column and slab loads for purposed structures will be 125 kips and 250 psf, respectively, and new fill heights will be 2 ft or less. This project information is based on information you provided to Ms. Angela Musselwhite, P.E. of our firm earlier this month, as well as the South Carolina Department of Commerce Site Certification Program Description and Instructions updated August Preliminary Geotechnical Exploration, MeadWestvaco Ridgeville Properties, Dorchester County, South Carolina, S&ME Project No S&ME, Inc. / 620 Wando Park Boulevard / Mt. Pleasant, South Carolina, / p / f /

38 Preliminary Geotechnical Exploration Additional MWV Ridgeville Properties 331 Acres; Dorchester County, SC S&ME Project No A October 23, 2009 FIELD EXPLORATION The general site subsurface conditions were explored by performing five widely-spaced cone penetration test (CPT) soundings to depths between 15 and 25 ft below the existing ground surface. Test locations were established using existing site features, and coordinates were recorded with a handheld GPS unit with submeter accuracy. To further evaluate the near-surface soils, we drilled a hand-auger boring to a depth of 4 ft adjacent to each sounding location. Figure 1 in the Appendix shows the approximate boring locations. A more detailed description of our field testing procedures, the CPT Sounding Logs, and Hand-Auger Boring Logs are included in the Appendix. In a CPT sounding (ASTM D 5778), an electronically instrumented cone penetrometer is hydraulically pushed through the soil to measure point stress, pore water pressure, and sleeve friction. The CPT data is used to determine soil stratigraphy and to estimate soil parameters such as preconsolidation stress, friction angle, and undrained shear strength. The hand-auger borings were drilled by manually turning a steel auger into the ground. The soils encountered were classified in the field by a Geotechnical Professional using the Unified Soil Classification System (USCS). SITE AND SUBSURFACE CONDITIONS Site Conditions The project site is located along US Highway 78 in Dorchester County, South Carolina as shown in Figures 1 and 2 in the Appendix. The site is bordered by undeveloped property to the south, undeveloped property and a skeet club to the west, the aforementioned MWV property to the east, and US Highway 78 to the north. At the time of our exploration, the site was wooded. Timothy Creek runs east to west near the southern border of the site. Unpaved roadways are located throughout the site, and an overhead power line easement runs north to south near the center of the site. Rutting and standing water was observed in several of these areas. Topographic information was not provided, but the site appeared relatively level at the time of our exploration. Subsurface Conditions Details of the subsurface conditions encountered by the soundings and hand-auger borings are shown on the logs in the Appendix. These logs represent our interpretation of the subsurface conditions based upon field data. Stratification lines on the sounding logs represent approximate boundaries between soil behavior types 2 ; however, the actual transition may be gradual. The 2 Soil Behavior Type is calculated based on empirical correlations which use the three fundamental penetrometer measurements (i.e., tip resistance, sleeve friction, and pore pressure). A CPT may define a soil based on its behavior as one type, while its grain size and plasticity (the traditional basis for soil classification) may define it as a different type. 2

39 Preliminary Geotechnical Exploration Additional MWV Ridgeville Properties 331 Acres; Dorchester County, SC S&ME Project No A October 23, 2009 general subsurface conditions and their pertinent characteristics are discussed in the following paragraphs. Initially, we encountered a surficial layer of topsoil approximately 2 to 10 in. thick. Beneath the topsoil, the subsurface conditions consisted of loose to dense sand to the top of a dense to very dense deposit that is likely part of the Cooper Group or Santee Formation. This deposit was encountered at depths ranging from 12 to 15 ft and continued to the deepest investigated depth of 25 ft. Several soundings encountered a thin ( 3 ft) very soft to firm clay layer between depths of 7 and 13 ft below grade. Groundwater Groundwater was measured in the borings and soundings at depths of approximately 5½ to 9 ft below the existing ground surface at the time of our exploration. Groundwater levels at the site will fluctuate during the year due to such things as seasonal and climatic variations and with construction activity in the area. Regional Geology Dorchester County, South Carolina, is located in the Coastal Plain Geologic Province. The Coastal Plain extends from the eastern limit of the Piedmont (Fall Line) eastward to the coast and consists of a wedge-shaped deposit of ancient marine sediments of the Late Cretaceous Period and younger. Coastal Plain soils comprise interbedded layers of unconsolidated and consolidated limestone, gravels, sands, silts, and clays. This wedge-shaped deposit ranges in thickness from near zero at the Fall Line to thousands of feet at the coast. Soil Survey Data The USDA Soil Conservation Service s (SCS) Soil Surveys can often provide helpful information about the shallow (< 6 ft) soils. Soil surveys map the near surface soils and provide general descriptions. The data is not intended to replace geotechnical evaluations and testing, but it can help identify trends. The SCS Soil Survey of Dorchester County, South Carolina, dated January 1990 indicates that the most predominant soils present at the site are of the Jedburg, Grifton, Foreston, Daleville, Pelham, and Ocilla series. These series are generally classified as fine sands, fine silty sands, fine clayey sands, low plasticity silts, and low plasticity clays. A summary of relevant data from the soil survey is shown in Table 1, and a Soil Survey Map is included as Figure 3 in the Appendix. 3

40 Preliminary Geotechnical Exploration Additional MWV Ridgeville Properties 331 Acres; Dorchester County, SC S&ME Project No A October 23, 2009 Table 1: Summary of Soil Conservation Service (SCS) Survey Data Dorchester County, South Carolina Soils Present in Upper 6 ft of the Additional MVW Property SCS Designation USCS Classification AASHTO Depth to Seasonal High Water Table (ft) Permeability (in/hr) Suitability as source of road fill Estimated limitations for foundations for dwellings Jedburg (Jd) SM, SM-SC, CL, SC A-4, A-6, A Poor; wetness Severe: wetness Grifton (Gr) SM, SM-SC, SC, CL A-2, A-4, A Poor; wetness Severe: flooding, wetness Foreston (FoA) SM, SP-SM, SC, SM-SC A-2, A-3, A-4, A-6, A Fair; wetness Moderate: wetness Daleville (Da) ML, CL-ML, CL A-4, A Poor; low strength, wetness Severe: wetness Pelham (Pe) SM, SP-SM, SM, SC, SM-SC A-2, A-4, A Poor; wetness Severe: wetness SM, SP-SM, CL, SC, Ocilla (OcA) A-2, A-3, A-4, A Fair; wetness Moderate: wetness ML Based on the soil survey information, the seasonal high water table ranges from the ground surface to 3.5 ft below the ground surface. The permeability of the predominant soils ranges from 0.6 to 20.0 in./hr. The predominant soil series pose severe limitations for foundations for dwellings and road fill due to low strength and wetness. Again, we emphasize that the SCS Soil Survey data is qualitative in nature. Furthermore, the SCS evaluations are based solely on the characteristics of the shallow (< 6 ft deep) soil stratigraphy and do not consider deeper soil conditions which can control foundation design. These soils are typical of the soil conditions in the site vicinity. In general, the difference between the fair and poor descriptions is the fines (i.e., silt and clay) content of the soils. The greater the fines content, the more moisture-sensitive the soil and the more difficult to work during construction. The difference between slight and severe limitations for foundations is the potential for flooding and associated strength and wetness. 4

41 Preliminary Geotechnical Exploration Additional MWV Ridgeville Properties 331 Acres; Dorchester County, SC S&ME Project No A October 23, 2009 PRELIMINARY COMMENTS AND CONCLUSIONS The preliminary analyses and conclusions submitted herein are based, in part, upon data obtained from our widely-spaced test locations. Subsurface conditions between the test locations will vary, as will grading and construction details. Therefore, we can only provide general comments about the suitability of the property for the anticipated construction. Once final site development plans have been established, additional geotechnical exploration and analysis will be required to provide recommendations for site preparation and foundation design. Based on the findings of our field exploration, we make the following preliminary comments and conclusions: 1. Site Drainage. Site work for individual projects or mass clearing and grading should begin with routine drainage improvements to help dry the site and handle rainfall runoff during construction. Drainage can typically be improved by excavating gravity draining ditches across the site to lower subsurface water levels and divert water away from the construction areas. Ditches should be excavated as deep as practical and as far in advance of mass clearing as possible. Even during dry weather conditions, ditches and drainage improvements should be in place to handle any heavy rainfall that might occur during construction. Any existing ditches can also be used. If sufficient fall is not available, ditches should be tied to sumps and pumped. 2. Site Preparation and Drainage Improvements. Site preparation would continue with removing unsuitable surface materials, including clearing and grubbing all vegetation and roots, stripping organic laden topsoil, and undercutting any unsuitable surface soils. Prior to fill placement, the exposed subgrade in proposed building and roadway areas will require thorough evaluation by a Geotechnical Engineer, to confirm that unsuitable materials are removed and that suitable soils are not over excavated. Since the near-surface soils are primarily sands, we do not anticipate that extensive undercutting will be required. However, near surface clayey soils were encountered and may comprise a large portion of the soils at any specific construction site. The amount of undercutting will depend on conditions at the time of construction, and some localized, shallow undercutting or densification may be necessary. Project grading budgets should include an allowance for some undercutting. 3. Foundations. Based on our preliminary exploration, the site soils appear suitable for support of the assumed structural load (i.e., < 125 kip columns and < 250 psf slabs) on conventional shallow foundations. Although our test locations are too widely spaced to provide final design values, we anticipate that conventional shallow foundations can be designed for maximum allowable bearing pressures in the range of 2,000 to 3,000 psf. Our preliminary analysis indicates that total post-construction static settlement will be 2 in. or less under the assumed structural loads and the weight of 2 ft or less of new fill. 5

42 Preliminary Geotechnical Exploration Additional MWV Ridgeville Properties 331 Acres; Dorchester County, SC S&ME Project No A October 23, 2009 Settlement should be more thoroughly assessed in a final geotechnical exploration tailored to the structural loads and fill heights specific to the planned development. 4. Seismic Considerations. While the IBC requires a 100-ft boring or sounding to determine Seismic Site Class, a shallower sounding may be used if the geotechnical engineers are familiar with the area soils. It may also be assumed that the shear wave velocities will increase with depth. Based on our preliminary analysis, there appears to be some risk of liquefaction 3 due to the 2006 International Building Code (IBC) design earthquake 4. Ground surface disruptions (sand boils) and liquefaction-induced settlements are theoretically possible; however, our preliminary analysis indicates the risk of significant sand boil development or large liquefaction-induced settlements is low. The IBC 2006 classifies a site as Seismic Site Class F if there is a possibility of liquefaction; however, the code allows the design spectral response accelerations for a site to be determined without regard to liquefaction provided the buildings have a fundamental period of less than or equal to 0.5 seconds and the risks of liquefaction are considered in design. Therefore, if future structures meet these criteria, it is our interpretation the site would be considered a Seismic Site Class D. 5. Controlled Fill. Any new, controlled fill material should be soil containing no more than 30% fines (material passing the No. 200 sieve) by weight, having a maximum dry density (ASTM D 1557) of at least 100 pcf, and having a Liquid Limit and Plastic Index of less than 40 and 5, respectively. The soil should be relatively free of organics, deleterious matter and elongated or flat particles susceptible to degradation. All fill should be placed in uniform lifts of 10 in. or less (loose measure), and compacted to at least 95% of the modified Proctor maximum dry density (ASTM D 1557). 6. Use of Excavation Soils as Structural Fill. Soils meeting the requirements for Controlled Fill as discussed above are preferred for use as structural fill and are most commonly used in this geographic area. The sandy soils at this site generally meet these requirements, though some moisture adjustment may be necessary to achieve the required compaction. The natural clayey soils at this site are also adaptable for use as structural fill to support the buildings and pavements. The feasible use of the clayey soils will be very dependent upon prevailing weather conditions and the Grading Contractor s experience, means, and methods. When handled properly, these soils can be used as fill, but the following measures are recommended: 3 Liquefaction, the loss of a soil s shear strength due to the increase in porewater pressure resulting from seismic vibrations, is always a potential concern in coastal South Carolina. 4 The IBC design earthquake has a 98% probability of non-exceedance in 50 years. Our liquefaction analysis was based on an earthquake with a magnitude of 7.3 and ground surface acceleration of 0.44g. 6

43 Preliminary Geotechnical Exploration Additional MWV Ridgeville Properties 331 Acres; Dorchester County, SC S&ME Project No A October 23, 2009 The soils will require more drying than typically expected during grading. This should be taken into consideration during the bidding phase of the project. Weather will greatly affect the use of the more clayey soils. During extended cool, wet weather conditions, the use of these soils may not be feasible. Grading contractors must have the proper equipment such as disc harrows and sheepsfoot compaction equipment to properly work these soils. The subgrade soils for slabs should not be allowed to dry significantly. This could require wetting and reworking the surface soils prior to slab installation. Consideration should be given to separating the floor slabs from the subgrade soils with a 6-in. thick layer of granular material. The granular material will serve as a capillary break, but it will also provide a more durable working surface during construction. 7. Pavements. Subsurface conditions are adaptable for typical slab and pavement design with proper site preparation and fill placement and compaction. Based on the exploration data and our experience, we would expect a soil modulus of subgrade reaction (k), based on the 30-in. diameter plate method, to be on the order of 150 to 200 pci. A vapor barrier may be required for the slab-on-grade, depending on the floor covering design. California Bearing Ratio (CBR) values on the order of 5 to 10 percent can be considered reasonable for conceptual design of flexible (i.e., asphalt) pavements. Flexible asphalt pavements typically are a minimum of about 8 in. thick (2 in. of asphalt and 6 in. of graded aggregate base) for automobile parking areas. Service drives are typically a minimum of about 11 in. thick (3 in. of asphalt and 8 in. of graded aggregate base). Rigid concrete pavements are typically used for dumpster pads and other heavy truck traffic areas, and they are typically at least 5 to 7 in. thick. We note that pavement thickness design is heavily dependent on the expected traffic type and volume, which are unknown at this point. 7

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45 APPENDIX Test Location Plan (Figure 1) Site Location Map (Figure 2) SCS Map (Figure 3) CPT Sounding Logs Hand-Auger Boring Logs Field Testing Procedures

46 C-12 C-11 C-13 C-14 C-15 Approximate Test Location This drawing was provided by BP Barber and Associates and adapted by S&ME, Inc. Test locations are approximate. Do not use for estimation of distances or quantities. Project No A October 2009 Scale As Shown TEST LOCATION PLAN Additional MWV Ridgeville Properties 331 Acres Dorchester County, South Carolina Figure 1

47 C-09 C-10 This drawing was provided by BP Barber and Associates. Do not use for estimation of distances or quantities. Project No October 2009 Scale as Shown Site Location Map MWV Ridgeville Properties Dorchester County, South Carolina Figure 2

48 This drawing was provided by BP Barber and Associates. Do not use for estimation of distances or quantities. Project No October 2009 Scale as Shown SCS Map MWV Ridgeville Properties Dorchester County, South Carolina Figure 3

49 Date: Estimated Water Depth: Rig/Operator: MWV Ridgeville Property Ridgeville, SC Cone Penetration Test C-11 S&ME Project No: A Oct. 16, 2009 Northing: 6 ft Easting: Gyrotrack/Andy Butch Elevation: Total Depth: Termination Criteria: Cone Size: 18.6 ft Maximum Reaction Force 1.44 Depth (ft) Tip Resistance q t (tsf) Sleeve Friction Pore Pressure f s u 2 u 0 (tsf) (tsf) Friction Ratio R f (%) Equivalent N SBT Bq MAI = 5 Depth (ft) Gravelly Sand to Sand 5 Sands-Clean Sand to Silty Sand 5 Sands-Clean Sand to Silty Sand Gravelly Sand to Sand 10 >> 10 Silt Mixtures-Clay Silt to Silty Clay Sand Mixtures-Silty Sand to Sandy Silt CPT REPORT - STANDARD - SBT BQ 09259ACPT.GPJ S&ME.GDT 10/22/09 15 Page 1 of 1 >> Electronic Filename: f16o0902c.dat Sands-Clean Sand to Silty Sand 15 C-11

50 MWV Ridgeville Property Ridgeville, SC Cone Penetration Test C-12 S&ME Project No: A Date: Oct. 16, 2009 Northing: Total Depth: 15.5 ft Estimated Water Depth: 8 ft Easting: Termination Criteria: Maximum Reaction Force Rig/Operator: Gyrotrack/Andy Butch Elevation: Cone Size: 1.44 Depth (ft) Tip Resistance q t (tsf) Sleeve Friction f s (tsf) Pore Pressure u 2 u 0 (tsf) Friction Ratio R f Equivalent N 60 (%) SBT Bq MAI = 5 Depth (ft) Gravelly Sand to Sand 5 5 Sands-Clean Sand to Silty Sand >> 10 Sands-Clean Sand to Silty Sand 10 >> >> Clays-Clay to Silty Clay CPT REPORT - STANDARD - SBT BQ 09259ACPT.GPJ S&ME.GDT 10/22/09 15 Page 1 of 1 >> >> Electronic Filename: f16o0907c.dat Sands-Clean Sand to Silty Sand 15 C-12

51 Date: Estimated Water Depth: Rig/Operator: MWV Ridgeville Property Ridgeville, SC Cone Penetration Test C-13 S&ME Project No: A Oct. 16, 2009 Northing: 5.5 ft Easting: Gyrotrack/Andy Butch Elevation: Total Depth: Termination Criteria: Cone Size: 21.5 ft Maximum Reaction Force 1.44 Depth (ft) Tip Resistance q t (tsf) Sleeve Friction Pore Pressure f s u 2 u 0 (tsf) (tsf) Friction Ratio R f (%) Equivalent N SBT Bq MAI = 5 Depth (ft) Gravelly Sand to Sand 5 Sands-Clean Sand to Silty Sand 5 Gravelly Sand to Sand Sands-Clean Sand to Silty Sand 10 Sand Mixtures-Silty Sand to Sandy Silt 10 Silt Mixtures-Clay Silt to Silty Clay Sands-Clean Sand to Silty Sand CPT REPORT - STANDARD - SBT BQ 09259ACPT.GPJ S&ME.GDT 10/22/ Page 1 of 1 >> Electronic Filename: f16o0903c.dat Sands-Clean Sand to Silty Sand Sand Mixtures-Silty Sandto Sandy Silt 15 Gravelly Sand to Sand Sand Mixtures-Silty Sand to Sandy Silt 20 C-13

52 MWV Ridgeville Property Ridgeville, SC Cone Penetration Test C-14 S&ME Project No: A Date: Oct. 16, 2009 Northing: Total Depth: 17.0 ft Estimated Water Depth: 9 ft Easting: Termination Criteria: Maximum Reaction Force Rig/Operator: Gyrotrack/Andy Butch Elevation: Cone Size: 1.44 Depth (ft) Tip Resistance q t (tsf) Sleeve Friction f s (tsf) Pore Pressure u 2 u 0 (tsf) Friction Ratio R f Equivalent N 60 (%) SBT Bq MAI = 5 Depth (ft) Gravelly Sand to Sand 5 >> 5 10 >> Sands-Clean Sand to Silty Sand 10 Sand Mixtures-Silty Sand to Sandy Silt CPT REPORT - STANDARD - SBT BQ 09259ACPT.GPJ S&ME.GDT 10/22/09 15 Page 1 of 1 >> >> Electronic Filename: f16o0906c.dat Sands-Clean Sand to Silty Sand 15 Gravelly Sand to Sand C-14

53 Date: Estimated Water Depth: Rig/Operator: Oct. 16, ft Gyrotrack/Andy Butch MWV Ridgeville Property Ridgeville, SC S&ME Project No: A Northing: Easting: Elevation: Cone Penetration Test C-15 Total Depth: 25.5 ft Termination Criteria: Maximum Reaction Force Cone Size: 1.44 Depth (ft) Tip Resistance q t (tsf) << Sleeve Friction f s (tsf) Pore Pressure u 2 u 0 (tsf) Friction Ratio R f (%) >> Equivalent N SBT Bq MAI = 5 Gravelly Sand to Sand Depth (ft) Sands-Clean Sand to Silty Sand 5 5 Sands-Clean Sand to Silty Sand 10 >> >> >> >> Gravelly Sand to Sand 10 Sands-Clean Sand to Silty Sand CPT REPORT - STANDARD - SBT BQ 09259ACPT.GPJ S&ME.GDT 10/22/ >> >> Sands-Clean Sand to 20 Silty Sand >> Page 1 of 1 Electronic Filename: f16o0904c.dat C-15

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59 FIELD TESTING PROCEDURES Cone Penetrometer Test (CPT) Sounding The cone penetrometer test soundings (ASTM D 5778) were performed by hydraulically pushing an electronically instrumented cone penetrometer through the soil at a constant rate. As the cone penetrometer tip was advanced through the soil, nearly continuous readings of point stress, sleeve friction and pore water pressure were recorded and stored in the on-site computers. Using theoretical and empirical relationships, CPT data can be used to determine soil stratigraphy and estimate soil properties and parameters such as effective stress, friction angle, Young s Modulus and undrained shear strength. The consistency and relative density designations, which are based on the cone tip resistance, q t for sands and cohesive soils (silts and clays) are as follows: SANDS Cone Tip Resistance, q t (tsf) Relative Density SILTS AND CLAYS Cone Tip Resistance, Consistency q t (tsf) <20 Very Loose <5 Very Soft Loose 5 10 Soft Medium Dense Firm Stiff Dense Very Stiff >200 Very Dense >60 Hard CPT Correlations References are in parenthesis next to the appropriate equation. General p a = atmospheric pressure (for unit normalization) q t = corrected cone tip resistance (tsf) f s = friction sleeve resistance (tsf) R f = 100% * (f s /q t ) u 2 = pore pressure behind cone tip (tsf) u 0 = hydrostatic pressure B q = (u 2 -u 0 )/(q t -σ v0 ) Q t = (q t -σ v0 )/ σ v0 F r = 100% * f s /(q t - σ v0 ) I c = ((3.47-logQ t ) 2 +(logf r +1.22) 2 ) 0.5 N-Value N 60 = (q t /pa)/[8.5(1-i c /4.6)] (6) (6) Jefferies, M.G. and Davies, M.P., (1993), Use of CPTu to estimate equivalent SPT N60, ASTM Geotechnical Testing Journal, Vol. 16, No. 4

60 CPT Soil Classification Legend Robertson's Soil Behavior Type (SBT), 1990 Group # Description Ic Min Max 1 Sensitive, fine grained N/A 2 Organic soils - peats 3.60 N/A 3 Clays - silty clay to clay Silt mixtures - clayey silt to silty clay Sand mixtures - silty sand to sandy silt Sands - clean sand to silty sand Gravelly sand to dense sand N/A Very stiff sand to clayey sand (High OCR or cemented) N/A 9 Very stiff, fine grained (High OCR or cemented) N/A Soil behavior type is based on empirical data and may not be representative of soil classification based on plasticity and grain size distribution. Relative Density and Consistency Table SANDS SILTS and CLAYS Cone Tip Stress, qt (tsf) Relative Density Cone Tip Stress, qt (tsf) Consistency Less than Greater than 200 Very Loose Loose Medium Dense Dense Very Dense Less than Greater than 60 Very Soft Soft to Firm Stiff Very Stiff Hard