Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot North Charleston, South Carolina S&ME Project No.

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1 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No PREPARED FOR: Seamon Whiteside 501 Wando Park Blvd, Suite 200 Mt. Pleasant, South Carolina PREPARED BY: S&ME, Inc. 620 Wando Park Boulevard Mount Pleasant, SC October 17, 2017

2 October 17, 2017 Seamon Whiteside 501 Wando Park Blvd, Suite 200 Mt. Pleasant, South Carolina Attention: Reference: Mr. Lee Gastley, PLA, LEED, AP Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No Dear Mr. Gastley: We have completed our geotechnical exploration for the proposed dog park, restroom facility, and parking lot at the Wannamaker County Park in. Our services were performed pursuant to S&ME Proposal No dated February 2, The purpose of our services was to explore the site subsurface conditions for the planned construction, evaluate those conditions, and provide geotechnical recommendations for site preparation and foundation support. This report presents our understanding of the project, the site and subsurface conditions encountered, and our conclusions and recommendations. Project Information We understand plans are to construct a new restroom building and parking lot for the dog park at Wannamaker County Park in. The proposed restroom building will be an approximately 50-ft by 45-ft, single story structure with a soil-supported floor slab. Specific structural information was not provided. Based on our experience with similar projects, we assume maximum column and wall loads will be on the order of 40 kips and 3 kips/ft, respectively. We assumed new fill heights of 2 ft or less will be required to grade the proposed building area. The proposed parking lot will be a 50-car parking area to serve the dog park and restroom facility. Project information was provided via from Mr. Lee Gastley to Ms. Tracey Turner of our firm on January 17, Updated project plans and information was sent in via from Mr. William O Neal to Ms. Turner on September 19, Methods of Exploration Our exploration included a site reconnaissance by a geotechnical engineer and the performance of two cone penetrometer test (CPT) soundings to a depth of approximately 26 ft below the existing ground surface. Hand auger borings were performed to a depth of approximately 4 ft below the existing ground surface adjacent to each sounding to further evaluate the near-surface soils. The soundings and hand auger borings were performed S&ME, Inc. 620 Wando Park Boulevard Mount Pleasant, SC p

3 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No within the approximate footprint of the proposed restroom building. Five additional 4-ft hand auger borings were also performed within the proposed parking lot area. The test locations were established in the field by S&ME personnel using a handheld GPS system. The approximate test locations are shown on the Test Location Plan in the Appendix. A more detailed description of our field testing procedures, the CPT Sounding Logs, and Hand-Auger Boring Logs are also included in the Appendix. Site and Subsurface Conditions Site Conditions Wannamaker County Park is located at 8888 University Boulevard in. The proposed dog park, restroom amenities, and parking lot will be located in the existing wooded area to the north of Fernwood Drive within the property of the park. At the time of our exploration, the ground surface consisted of primarily pine straw or mulch within the wooded area. Subsurface Conditions Details of the subsurface conditions encountered by the soundings and 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 1 ; however, the actual transition may be gradual. The general subsurface conditions and their pertinent characteristics are discussed in the following paragraphs. The exploration initially encountered approximately 1 to 3 inches of topsoil underlain by a mix of low consistency clayey sand and sandy clay to a depth of about 2 ft in C-2. Beneath the topsoil and low consistency soils, the subsurface conditions generally consisted of very loose to medium dense sand and firm to stiff clay to the top of the Cooper Marl, 2 which was encountered at a depth of about 25 ft below the existing ground surface and continued to the deepest explored depth of 26 ft. Subsurface Water Subsurface water was measured upon completion of the soundings and hand auger borings at depths within 1-ft of the existing ground surface. Subsurface water levels at the site will fluctuate during the year due to such things as seasonal and climatic variations and the construction activity in the area. 1 Soil Behavior Type is calculated based on empirical correlations with 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 The Cooper Marl, locally referred to as marl, is a relatively incompressible, thick ( 200 ft) stratum which underlies the area and is typically the bearing stratum for deep foundations in the Charleston area. October 17,

4 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No Conclusions and Recommendations The exploration indicates the site is adaptable for the proposed construction. The proposed building may be supported on conventional shallow foundations bearing in well-compacted controlled fill or suitable in-place soils provided our site preparation recommendations are followed and the risks associated with liquefaction are mitigated. The following presents our geotechnical recommendations regarding site grading and foundation support. During review of these recommendations, it should be kept in mind that subsurface conditions will vary between test locations. Variable conditions can normally be handled during construction by field engineering evaluation. Site Preparation Subsurface water levels are shallow at the site. Depending on conditions at the time of clearing operations and construction, site preparation will likely need to begin with drainage improvements to drain ponded water, lower groundwater levels, and handle stormwater runoff during construction. This can probably be accomplished by excavating a system of gravity-draining ditches. Ditches should be excavated as deep as practical and as far in advanced of general earthwork as possible. If sufficient fall is not available, ditches should be tied to sumps and pumped. Even during dry weather conditions, ditches and drainage improvements should be in place to handle any heavy rainfall that occur during construction. Site preparation should begin with clearing and grubbing of all pine straw, mulch, vegetation, trees and roots, stripping organic-laden topsoil, and undercutting unsuitable surface soils. If encountered, stumps and taproots should be completely removed from the building area, and voids created should be cleaned and backfilled with well-compacted controlled fill. Prior to new fill placement or foundation construction, the exposed subgrade should be proofrolled with a heavily-loaded tandem-axle dump truck or similar rubber-tired equipment under the observation of the Geotechnical Engineer. Areas that pump or rut excessively should be densified in place or stabilized as recommended by the Geotechnical Engineer. Proofrolling will not only densify the subgrade prior to new fill placement, but it will expose unstable subgrade areas. All undercutting should be observed by the Geotechnical Engineer to determine that all unsuitable materials are removed and to prevent removal of suitable materials. The natural near-surface clayey soils at this site are moisture sensitive and will lose stability when wet. Additionally, low consistency soils were encountered in the upper 2 ft in some areas of the site. As such, thorough subgrade evaluations and proofrolling will be very important, and some undercutting and replacement of existing in situ soils should be anticipated. The extent and depth of undercutting will be dependent on final grades, the weather conditions during construction, the aggressiveness of the earthwork schedule, site drainage, and the grading contractor s means and methods. Controlled Fill Controlled fill material should be cohesionless soil containing no more than 15% fines (material passing the No. 200 sieve) by weight and having a maximum dry density of at least 100 pcf as determined by a laboratory modified Proctor compaction test (ASTM D 1557). The soil should be relatively free of organics, deleterious matter, October 17,

5 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No 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. Fill placement and compaction operations should be observed by a qualified engineering technician working under the direction of the Geotechnical Engineer. In addition to this visual evaluation, the technician should perform a sufficient number of in-place field density tests to confirm the contractor s equipment and methods are capable of achieving the required degree of compaction. Seismic Considerations A liquefaction 3 analysis was performed based on the design earthquake prescribed by the 2015 edition of the International Building Code (IBC 2015) 4 and the simplified procedure as presented in Youd et al. (2001). This analysis indicates the sands at this site have the potential to liquefy during the design seismic event. The Liquefaction Potential Index (LPI) was computed to help evaluate the consequences of liquefaction. The LPI is an empirical tool used to evaluate the site liquefaction hazard and the potential for liquefaction-induced damages 5. The LPI considers the factor of safety against liquefaction, the depth to the liquefiable soils, and the thickness of the liquefiable soils to compute an index that ranges from 0 to 100. An LPI of 0 means there is no risk of liquefaction; an LPI of 100 means the entire profile is expected to liquefy. The level of risk is generally defined as: LPI < 5 surface manifestation and liquefaction-induced damage not expected. 5 LPI 15 moderate liquefaction with some surface manifestation possible. LPI > 15 severe liquefaction and foundation damage is likely. The LPI for this site is greater than 15, which indicates the liquefaction risk is moderate and some surface manifestation is possible. Our analysis predicts about 3 to 4 in. of free-field liquefaction-induced settlement is possible at this site. Section of the IBC 2015 classifies sites with the potential for liquefaction as Seismic Site Class F. However, the IBC 2015 allows the design spectral response accelerations for a site to be determined without regard to liquefaction provided buildings have a fundamental period of less than or equal to 0.5 seconds and the risks of liquefaction are considered in design. The proposed structure should meet this criteria; however, this must be confirmed by the Structural Engineer. If the liquefaction potential is mitigated through ground improvement, as discussed in the next section, a Site Class D may be used. 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 2% probability of exceedance in 50 years. This is statistically equivalent to an event that occurs about once every 2,500 years. Our liquefaction analysis was based on an earthquake with a magnitude of 7.3 and ground surface acceleration of 1.15g. 5 Iwasaki et al. 1982, Toprak & Holzer (2003). October 17,

6 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No In summary, in the absence of any ground improvement, the site should be considered as Site Class F. If the liquefaction potential is mitigated through ground improvement, the site should be considered as Site Class D. With or without ground improvement, the design accelerations may be calculated on the basis of a Site Class D assumption, provided the structure(s) has a fundamental period of 0.5 seconds or less. If the structure has a period of more than 0.5 seconds, a site-specific response analysis (SSRA) will have to be performed to determine the design acceleration. The design values for the various conditions are presented in Table 1. Table 1 Spectral Response Accelerations and Site Coefficients Site Class Ss S1 Fa Fv PGAM SDS SD1 F 1.65 g 0.56 g g 1.01 g 0.56 g Ground Improvement Techniques If the proposed building cannot be designed to accommodate the predicted 3 to 4 in. of liquefaction-induced settlement without collapse, our analysis indicates ground improvement consisting of earthquake (EQ) drains can be used to reduce seismic settlements and allow for shallow foundation support of the proposed building. The goal of the ground improvement program should be to reduce liquefaction-induced settlements of the IBC 2015 design earthquake in building areas to levels acceptable to the structural engineer. Earthquake Drains Earthquake (EQ) drains can reduce seismic settlement to acceptable levels; however, the drains cannot totally eliminate seismic settlement. The drains allow for the rapid dissipation of excess soil porewater pressures generated during a seismic event thus reducing liquefaction. The drains are composed of corrugated, perforated plastic pipe encased in a filter fabric which prevents migration of fines into the pipe. Pipe diameters and spacings vary according to the anticipated liquefaction risk and may be supplemented with man-made gravel reservoirs for additional water storage. Earthquake drains are typically provided in a design-build contract by a specialty contractor experienced with the design and installation of the system. We recommend a request be submitted to qualified contractors to prepare a proposal to furnish all necessary labor, equipment, and materials to design and install EQ drains to reduce liquefaction-induced settlements for the IBC 2015 design earthquake in building areas to a magnitude acceptable to the structural engineer. The IBC 2015 design event comprises a 7.3 magnitude earthquake with a peak ground acceleration (PGA) of 1.15g. A copy of this report should be submitted with the request to provide the necessary subsurface data to perform the design. EQ drain installation should be observed by a representative of the Geotechnical Engineer to confirm that 1) EQ drains are installed in all locations, 2) EQ drains are installed to the design depth, and 3) note any nonconformance with the EQ drain design. October 17,

7 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No Shallow Foundation Recommendations The proposed building may be supported on shallow foundations bearing in well-compacted controlled fill or suitable on-site soils designed for a maximum allowable soil bearing pressure of 2,000 psf provided our site preparation recommendations are followed and the risks associated with liquefaction are accepted or mitigated. Building footings should bear a minimum of 12 in. below grade to develop the design bearing pressure. Wall and column footings should be a minimum of 18 and 24 in. wide, respectively. This recommendation is made to help prevent a "localized" or "punching" shear failure condition, which could exist with very narrow footings. All foundation excavation bottoms must be evaluated by a representative of the Geotechnical Engineer prior to steel and concrete placement. This evaluation should include probing, hand-auger borings, and dynamic cone penetrometer (DCP) testing and will help determine if individual footings are directly underlain by suitable bearing material. This evaluation is particularly important since low consistency soils were encountered in the upper 2 ft in some areas of the site. If this material is encountered during footing evaluations, it should be undercut from footing bottoms. Any loose material should be properly compacted or undercut and replaced with wellcompacted controlled fill. If practical, concrete placement should be completed the same day as the footing excavation. Slag is not recommended as backfill due to its potentially expansive nature. Our analysis indicates post-construction, static (not seismically-induced) settlement due to the assumed building loads (i.e. 40 kips columns and 3 kips/ft walls) and 2 ft of new fill will be 1½ in. or less. Differential settlement is typically assumed to be about half of the total settlement. If actual building loads will be greater than those assumed in this report or more than 2 ft of new fill will be placed in the proposed building area, we should be provided with this information so that we can reevaluate settlement. This is very important because higher building loads and additional fill will cause additional settlement. Soil Supported Slabs Grade slabs may be soil-supported provided our site preparation, fill placement and compaction recommendations are followed and the risks associated with liquefaction are mitigated. A subgrade modulus (k) of 180 pci is available for design. This recommended modulus is representative of a 30-in. diameter plate load test and is only applicable for light point loads. This modulus must be reduced for wide area loads. Based on the results of our exploration, floor slabs will not be subjected to hydrostatic pressure from groundwater. However, water vapor transmission through the slab is still a design consideration. Evaluating the need for and design of a vapor retarder or vapor barrier for moisture control is outside our scope of services and should be determined by the project architect or structural engineer based on the planned floor coverings and the corresponding design constraints, as outlined in ACI 302.1R-04 Guide for Concrete Floor and Slab Construction Excavations Subsurface water was encountered within 1-ft of the existing ground surface. Water levels should be maintained at least 1 ft below excavations to help maintain bottom stability. Water can probably be controlled at the site by pumping from sumps located within the excavation or well-point system. The effects of dewatering on nearby structures should be evaluated and are the responsibility of the designer of any dewatering system. October 17,

8 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No All excavations should be sloped or shored in accordance with local, state, and federal regulations, including OSHA (29 CFR Part 1926) excavation trench safety standards. The contractor is solely responsible for site safety. This information is provided only as a service, and under no circumstances should S&ME be assumed to be responsible for construction site safety. Pavement Recommendations We have evaluated new flexible (asphalt) using the SCDOT Pavement Design Guide and associated literature. Traffic loading data was not provided. Based on our experience with similar projects, we assume light-duty pavement will be subjected primarily to passenger cars and light truck traffic and heavy-duty pavements will be subjected to heavier truck traffic. A CBR value of 10% was used in the design of all pavement sections. This value is based our experience with sites that have similar soils and subgrades consisting of at least 24 in. of well-compacted controlled fill. The CBR values should be confirmed during grading by engineering evaluation and field and laboratory testing. Table 2 presents our recommendations for minimum pavement sections. Table 2. Minimum Recommended Pavement Sections Material Asphaltic Concrete Surface Course (SCDOT Type C) Graded Aggregate Base Course Compacted Subgrade Flexible Pavement Heavy Duty Standard Duty 3 in. 2 in. 8 in. 6 in. 24 in. Our analyses indicate the standard duty flexible pavement section has an allowable traffic volume of about 30,000 ESALs 6, and the allowable traffic volume for the heavy duty flexible pavement section is approximately 250,000 ESALs. Based on our experience, this should be adequate for the assumed traffic and a typical 15-year pavement life. Construction traffic has not been included in our analysis, and construction traffic should be restricted from prepared subgrades and new pavements. If pavements must support construction traffic, stage construction or a thicker asphalt section will be required. All materials and workmanship should be in accordance with the South Carolina Department of Transportation s Standard Specifications for Highway Construction, 2007 Edition. 6 Equivalent 18-kip single axle load (ESAL). For example, a legally-loaded tandem axle tractor-trailer has an ESAL of up to 2.5, while a passenger car has an ESAL of approximately October 17,

9 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No A stable subgrade is very important to pavement performance. Immediately prior to paving, the subgrade should be proofrolled, and any unstable areas should be repaired. The base course should be compacted to at least 100% of the maximum dry density as determined by the modified Proctor compaction test (ASTM D 1557). Inplace field density tests should be performed by a qualified Materials Technician, and the area should be methodically proofrolled under their evaluation to confirm that the base course has been uniformly compacted. The thickness should not be deficient in any area by more than ½ in. The asphalt pavement thickness should not be deficient by more than ¼ in. in any area. The performance of asphalt and rigid concrete pavements will be dependent upon a number of factors including subgrade conditions at the time of paving, drainage, and traffic. The geometric design should provide positive drainage for the pavement surface and subgrades. Pavement design typically has relatively low factors of safety; therefore, it will be very important that the specifications are followed closely during pavement construction. Our analysis was based on a 15-year design life; however, some isolated areas could require repair in a shorter period of time. Limitations 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 are based upon applicable standards of our practice in this geographic area at the time this report was prepared. No other warranty, either express or implied, is made. We relied on project information given to us to develop our conclusions and recommendations. If project information described in this report is not accurate, or if it changes during project development, we should be notified of the changes so that we can modify our recommendations based on this additional information if necessary. Our conclusions and recommendations are based on data from widely spaced test locations. Subsurface conditions can vary widely between explored areas. Some variations may not become evident until construction. If conditions are encountered which appear different than those described in our report, we should be notified. This report should not be construed to represent subsurface conditions for the entire site. Unless specifically noted otherwise, our field exploration program did not include an assessment of regulatory compliance, environmental conditions or pollutants or presence of any biological materials (mold, fungi, bacteria, etc.). If there is a concern about these items, other studies should be performed. S&ME can provide a proposal and perform these services if requested. S&ME should be provided the opportunity to review the final plans and specifications to confirm that earthwork, foundation, and other recommendations are properly interpreted and implemented. The recommendations in this report are contingent on S&ME s review of final plans and specifications followed by observation and monitoring of earthwork and foundation construction activities. October 17,

10 Geotechnical Exploration Proposed Dog Park, Restroom Building, and Parking Lot S&ME Project No Closure S&ME appreciates the opportunity to be of service on this project. If you have any questions concerning this report, please call. Sincerely, S&ME, Inc. E. Lehe Fender, Jr., E.I.T. Project Professional Tracey R. Turner, P.E. Senior Engineer / Project Manager October 17,

11 Appendices Test Location Plan (Figure 1) CPT Sounding Logs Hand Auger Boring Logs

12 N C-1 C-2 HA-3 HA-4 HA-5 HA-6 Drawing Path: Q:\drawings\1413\2017\021 Wannamaker\ _recover.dwg HA Distribution Airbus DS 2017 Microsoft Corporation GRAPHIC SCALE (IN FEET) SCALE: PROPOSED TEST LOCATIONS 1" = 100' WANNAMAKER PART III CHARLESTON COUNTY PARKS & RECREATION NORTH CHARLESTON, SOUTH CAROLINA DATE: PROJECT NUMBER FIGURE NO. 1

13 Restroom Building - Wannamaker Park S&ME Project No: Date: Estimated Water Depth: Rig/Operator: Oct. 12, ft ATV/L. Cooper Sounding ID: C-1 Total Depth: 25.5 ft Termination Criteria: Target Depth Cone Size: 1.75 Depth (ft) 0 Tip Resistance q t (tsf) Sleeve Friction Pore Pressure f s (tsf) u 2 (tsf) u Friction Ratio R f (%) Equivalent N SBT Fr MAI = 5 Depth (ft) 0 5 Very Stiff Fine Grained Soils 5 10 Very Stiff Clay to Clayey Sand Sands-Clean Sand to Silty Sand 15 CPT REPORT - STANDARD - SBT FR CPT.GPJ S&ME.GDT 10/13/ Page 1 of 1 Electronic Filename: C-1_PD.DAT Sand Mixtures-Silty Sand to Sandy Silt Sands-Clean Sand to Silty Sand Cone Penetration Test 20 25

14 Restroom Building - Wannamaker Park S&ME Project No: Date: Estimated Water Depth: Rig/Operator: Oct. 12, ft ATV/L. Cooper Sounding ID: C-2 Total Depth: 26.0 ft Termination Criteria: Target Depth Cone Size: 1.75 Depth (ft) 0 Tip Resistance q t (tsf) Sleeve Friction Pore Pressure f s (tsf) u 2 (tsf) u Friction Ratio R f (%) << >> Equivalent N SBT Fr MAI = 5 Depth (ft) 0 5 Very Stiff Fine Grained Soils Sands-Clean Sand to Silty Sand 15 CPT REPORT - STANDARD - SBT FR CPT.GPJ S&ME.GDT 10/13/ Page 1 of 1 Electronic Filename: C-2_PD.DAT Sand Mixtures-Silty Sand to Sandy Silt Sands-Clean Sand to Silty Sand Cone Penetration Test 20 25

15 PROJECT: DATE STARTED: Restroom Building - Wannamaker Park /12/17 DATE FINISHED: 10/12/17 HAND AUGER BORING LOG: C-1 NOTES: Removed 4 inches of pinestraw / mulch SAMPLING METHOD: Hand-Auger PERFORMED BY: L.Fender WATER LEVEL: Groundwater encountered at 1 foot at time of boring Depth GRAPHIC LOG MATERIAL DESCRIPTION ELEVATION WATER LEVEL TOPSOIL = 1 in. SLIGHTLY CLAYEY SAND (SP-SC) Dark brown, fine, trace small roots CLAYEY SAND (SC) Light reddish brown, fine, trace red mottling 1 CLAY (CL) Light reddish brown, trace red mottling With dark red mottling 3 4 Boring terminated at 4 ft DCP INDEX IS THE DEPTH (IN.) OF PENETRATION PER BLOW OF A 10.1 LB HAMMER FALLING 22.6 IN., DRIVING A 0.79 IN. O.D. 60 DEGREE CONE. Page 1 of Wando Park Blvd Mount Pleasant, SC 29464

16 PROJECT: DATE STARTED: Restroom Building - Wannamaker Park /12/17 DATE FINISHED: 10/12/17 HAND AUGER BORING LOG: C-2 NOTES: Removed 1 inch of pinestraw / mulch SAMPLING METHOD: Hand-Auger PERFORMED BY: L.Fender WATER LEVEL: Groundwater encountered at 1 foot at time of boring Depth GRAPHIC LOG MATERIAL DESCRIPTION ELEVATION WATER LEVEL TOPSOIL = 1 in. SLIGHTLY CLAYEY SAND (SP-SC) Dark yellowish brown, fine, some small roots CLAYEY SAND (SC) Dark yellowish brown, fine 1 2 CLAY (CL) Yellowish brown, some light reddish brown mottling Light gray, with dark red mottling 4 Boring terminated at 4 ft DCP INDEX IS THE DEPTH (IN.) OF PENETRATION PER BLOW OF A 10.1 LB HAMMER FALLING 22.6 IN., DRIVING A 0.79 IN. O.D. 60 DEGREE CONE. Page 1 of Wando Park Blvd Mount Pleasant, SC 29464

17 PROJECT: DATE STARTED: Restroom Building - Wannamaker Park /12/17 DATE FINISHED: 10/12/17 HAND AUGER BORING LOG: HA-3 NOTES: Removed 1 inch of pinestraw / mulch SAMPLING METHOD: Hand-Auger PERFORMED BY: L.Fender WATER LEVEL: Groundwater encountered at 1 foot at time of boring Depth GRAPHIC LOG MATERIAL DESCRIPTION ELEVATION WATER LEVEL TOPSOIL = 3 in. CLAYEY SAND (SC) Light gray to yellowish bown, fine, few small roots CLAY (CL) Light gray to yellowish brown Some light red mottling With dark red mottling 4 Boring terminated at 4 ft DCP INDEX IS THE DEPTH (IN.) OF PENETRATION PER BLOW OF A 10.1 LB HAMMER FALLING 22.6 IN., DRIVING A 0.79 IN. O.D. 60 DEGREE CONE. Page 1 of Wando Park Blvd Mount Pleasant, SC 29464

18 PROJECT: DATE STARTED: Restroom Building - Wannamaker Park /12/17 DATE FINISHED: 10/12/17 HAND AUGER BORING LOG: HA-4 NOTES: Removed 3 inches of pinestraw / mulch SAMPLING METHOD: Hand-Auger PERFORMED BY: L.Fender WATER LEVEL: Groundwater encountered at 0.5 feet at time of boring Depth GRAPHIC LOG MATERIAL DESCRIPTION ELEVATION WATER LEVEL TOPSOIL = 1 in. CLAYEY SAND (SC) Light gray, fine CLAY (CL) Light gray, with red mottling Yellowish brown, with red mottling 3 4 Boring terminated at 4 ft DCP INDEX IS THE DEPTH (IN.) OF PENETRATION PER BLOW OF A 10.1 LB HAMMER FALLING 22.6 IN., DRIVING A 0.79 IN. O.D. 60 DEGREE CONE. Page 1 of Wando Park Blvd Mount Pleasant, SC 29464

19 PROJECT: DATE STARTED: Restroom Building - Wannamaker Park /12/17 DATE FINISHED: 10/12/17 HAND AUGER BORING LOG: HA-5 NOTES: Removed 1 inch of pinestraw / mulch SAMPLING METHOD: Hand-Auger PERFORMED BY: L.Fender WATER LEVEL: Groundwater encountered at 1 foot at time of boring Depth GRAPHIC LOG MATERIAL DESCRIPTION ELEVATION WATER LEVEL TOPSOIL = 1 in. SLIGHTLY CLAYEY SAND (SP-SC) Dark yellowish brown, fine, trace small roots CLAYEY SAND (SC) Yellowish brown, fine 1 2 CLAY (CL) Yellowish brown, with light reddish brown mottling 3 4 Boring terminated at 4 ft DCP INDEX IS THE DEPTH (IN.) OF PENETRATION PER BLOW OF A 10.1 LB HAMMER FALLING 22.6 IN., DRIVING A 0.79 IN. O.D. 60 DEGREE CONE. Page 1 of Wando Park Blvd Mount Pleasant, SC 29464

20 PROJECT: DATE STARTED: Restroom Building - Wannamaker Park /12/17 DATE FINISHED: 10/12/17 HAND AUGER BORING LOG: HA-6 NOTES: Removed 1 inch of pinestraw / mulch SAMPLING METHOD: Hand-Auger PERFORMED BY: L.Fender WATER LEVEL: Groundwater encountered at 0.25 feet at time of boring Depth GRAPHIC LOG MATERIAL DESCRIPTION ELEVATION WATER LEVEL TOPSOIL = 2 in. CLAYEY SAND (SC) Dark yellowish brown, fine, with small roots Trace small roots 1 CLAY (CL) Yellowish brown, trace large root, trace red mottling 2 3 CLAYEY SAND (SC) Light gray to dark yellowish brown, fine 4 Boring terminated at 4 ft DCP INDEX IS THE DEPTH (IN.) OF PENETRATION PER BLOW OF A 10.1 LB HAMMER FALLING 22.6 IN., DRIVING A 0.79 IN. O.D. 60 DEGREE CONE. Page 1 of Wando Park Blvd Mount Pleasant, SC 29464

21 PROJECT: DATE STARTED: Restroom Building - Wannamaker Park /12/17 DATE FINISHED: 10/12/17 HAND AUGER BORING LOG: HA-7 NOTES: Removed 1 inch of pinestraw / mulch SAMPLING METHOD: Hand-Auger PERFORMED BY: L.Fender WATER LEVEL: Groundwater encountered at 0.5 feet at time of boring Depth GRAPHIC LOG MATERIAL DESCRIPTION ELEVATION WATER LEVEL TOPSOIL = 2 in. CLAYEY SAND (SC) Dark yellowish brown, fine, few roots CLAY (CL) Yellowish brown, few roots, trace red mottling With red mottling, trace root 2 3 CLAYEY SAND (SC) Light gray to dark yellowish brown, fine 4 Boring terminated at 4 ft DCP INDEX IS THE DEPTH (IN.) OF PENETRATION PER BLOW OF A 10.1 LB HAMMER FALLING 22.6 IN., DRIVING A 0.79 IN. O.D. 60 DEGREE CONE. Page 1 of Wando Park Blvd Mount Pleasant, SC 29464

22 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, q t (tsf) Consistency <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

23 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 20 Very Loose Less than 5 Very Soft Loose 5-15 Soft to Firm Medium Dense Stiff Dense Very Stiff Greater than 200 Very Dense Greater than 60 Hard

24 FIELD TESTING PROCEDURES Hand-auger Borings Hand-auger borings are performed by manually turning a steel auger into the ground. The soils encountered are visually classified in the field using the Unified Soil Classification System (USCS). If encountered, subsurface water level depths are measured from the existing ground surface at the time of boring. Upon completion, the bore hole was immediately backfilled with the cuttings.