Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
PA2101-SY210112
ECS Southwest, LLP Geotechnical Engineering Report Thweatt Park Detention Pond SWC of W Sandy Lake Road and S. Coppell Road Coppell, Texas ECS Project Number 19:8140 January 12, 2021 January 12, 2021 Mr. Mike Dellies, P.E., C.F.M. Director of Water Resources TNP 5237 N. Riverside Drive, Suite 100 Fort Worth, Texas 76137 ECS Project No. 19:8140 Reference: Geotechnical Engineering Report Thweatt Park Detention Pond SWC of W. Sandy Lake Road and S. Coppell Road Coppell, Texas Dear Mr. Dellies: ECS Southwest (ECS) has completed the subsurface exploration, laboratory testing, and geotechnical engineering analyses for the referenced project. Our services were performed in general accordance with our Proposal No. 19:10463-GP, dated October 23, 2020. This report presents our understanding of the geotechnical aspects of the project along with the results of the field exploration and laboratory testing conducted. The report also contained our findings and recommendations for design and construction. It has been our pleasure to be of service to you during design phase of this project. We would appreciate the opportunity to remain involved during the continuation of the design phase. We also would like to provide our services during construction phase operations to verify the assumptions of subsurface conditions made for this report. Should you have any questions concerning the information contained in this report, or if we can be of further assistance to you, please contact us. Respectfully submitted, ECS Southwest, LLP Che-Hung (Chris) Tsai, Ph.D., P.E. Michael Batuna, P.E. Geotechnical Senior Project Manager Principal Engineer ctsai@ecslimited.com mbatuna@ecslimited.com The electronic seal on this document was authorized by Michael P. Batuna No. 92147, on January 12, 2021 Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page i TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................. 1 1.0 INTRODUCTION .................................................................................................................. 2 1.1 General ................................................................................................................................... 2 1.2 Scope of Services .................................................................................................................... 2 1.3 Authorization .......................................................................................................................... 2 2.0 PROJECT INFORMATION ..................................................................................................... 3 2.1 Project Location...................................................................................................................... 3 2.2 Current Site Conditions .......................................................................................................... 3 2.3 Proposed Construction ........................................................................................................... 3 3.0 FIELD EXPLORATION ........................................................................................................... 4 3.1 Field Exploration Program ...................................................................................................... 4 3.2 Regional Geology .................................................................................................................... 4 3.3 Subsurface Characterization .................................................................................................. 5 3.4 Groundwater Observations .................................................................................................... 5 4.0 LABORATORY TESTING ........................................................................................................ 7 5.0 FINDINGs and RECOMMENDATIONS ................................................................................... 8 5.1 Current Conditions ................................................................................................................. 8 5.2 Findings .................................................................................................................................. 8 5.3 Detention Pond Improvements .............................................................................................. 8 6.0 SITE CONSTRUCTION RECOMMENDATIONS ....................................................................... 10 6.1 Subgrade Preparation .......................................................................................................... 10 6.1.2 Proofrolling ................................................................................................................. 10 6.2 Earthwork Operations .......................................................................................................... 10 6.3 Material Specifications ......................................................................................................... 11 6.3.3 On-site Soil .................................................................................................................. 11 6.3.4 Imported Clay Soil ....................................................................................................... 11 7.0 CLOSING ........................................................................................................................... 12 Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page ii APPENDICES Appendix A – Figures · Site Location Diagram · Boring Location Diagram · Regional Geology Appendix B – Field Operations · Reference Notes for Boring Logs · Boring Logs B-1 through B-4 Appendix C – Laboratory Testing · Laboratory Testing Summary · Particle Size Distribution Results Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 1 EXECUTIVE SUMMARY The following summarizes the main findings of the exploration, particularly those that may have a cost impact on the planned roadway development. Information gleaned from the executive summary should not be utilized in lieu of reading the entire geotechnical report. · The geotechnical exploration performed for this study consisted of four borings drilled for to a depth of 20 feet below the existing site grades. · Based on the subsurface conditions encountered in the borings, on-site soils generally consist of clayey sand, poorly to well graded sand with clay and gravel, and fat to lean clays underlain by gray shale. Gray shale was generally encountered at depths of 10 to 13 feet below the existing grade. · Brittle plastic liner was observed at several locations in the pond area. Sandy soils with high capacity of the permeability were encountered in the boings from the exiting grades to a depth of 13 feet below the existing grade in the borings. It is our opinion the leaking of the pond results from the presence of these sandy soil. Plastic linear should be replaced with new linear, or a clay linear should be used to cover the surface of the detention pond. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 2 1.0 INTRODUCTION 1.1 GENERAL The purpose of this study was to provide geotechnical information for the evaluation a detention pond in Coppell, Texas. The recommendations developed for this report are based on project information provided by the client. This report contains the results of our subsurface explorations and geotechnical laboratory testing programs, site characterization, engineering analyses, and recommendations for the planned detention pond improvements. 1.2 SCOPE OF SERVICES To obtain the necessary geotechnical information required for the evaluation of subsurface soil conditions at the project site, four borings were performed at selected locations within the detention pond. A laboratory-testing program was also implemented to characterize the physical and geotechnical engineering properties of the subsurface soils. This report discusses our exploratory and testing procedures, presents our findings and evaluations and includes the following: · A review of our field and laboratory test procedures and the results of testing conducted. · A review of site conditions. · A review of site geologic conditions. · A review of subsurface soil stratigraphy with pertinent available physical properties. · Boring logs drilled for the detention pond. · Recommendations for site preparation and construction of compacted fills for site grading. 1.3 AUTHORIZATION Our services were provided in accordance with our Proposal No. 19:10463-GP, dated October 23, 2020, and authorized by the client on November 16, 2020. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 3 2.0 PROJECT INFORMATION 2.1 PROJECT LOCATION The project site is an existing Thweatt Park detention pond located at southwest corner of W. Sandy Lake Road and S. Coppell Road in Coppell, Texas. The location is depicted in the attached Site Location Diagram in Appendix A. 2.2 CURRENT SITE CONDITIONS The diameter of the project detention pond is estimated to be about 140 feet and about 8 to 10 feet deep. We were informed that the pond may have problems to hold the water and it is leaking through the existing plastic liner. Currently, the liner is exposed in several areas in the pond area, and where the liner is exposed, it is very brittle. 2.3 PROPOSED CONSTRUCTION The proposed project consists of the evaluation of subsurface conditions at the project detention pond. We understand the project will include the improvements of the detention pond with new liners. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 4 3.0 FIELD EXPLORATION 3.1 FIELD EXPLORATION PROGRAM The field exploration was planned with the objective of characterizing the project site in general geotechnical and geological terms and to evaluate subsequent field and laboratory data to assist in the determination of geotechnical recommendations. The subsurface conditions were explored by drilling four borings on the top of the detention pond. The borings were drilled to depths of 20 feet below the existing grades. A truck-mounted drilling rig with continuous flight augers was utilized to drill the borings. The boring locations were identified in the field by ECS personnel using the supplied site plan. The approximate as-drilled boring location is shown on the Boring Location Diagram in Appendix A. The ground surface elevations noted on the boring logs were obtained from NCTCOG web site, which provided elevation contours in 2 foot intervals. Representative soil samples by truck were obtained by means of the split-barrel and Shelby tube sampling procedures in accordance with ASTM Specifications D-1586 and D-1587, respectively. In the split-barrel sampling procedure, a 2-inch O.D., split-barrel sampler is driven into the soil a distance of 18 inches by means of a 140-pound hammer falling 30 inches. The number of blows required to drive the sampler through a 12-inch interval is termed the Standard Penetration Test (SPT) value and is indicated for each sample on the boring logs. In the Shelby tube sampling procedure, a thin walled, steel seamless tube with sharp cutting edge is pushed hydraulically into the soil, and a relatively undisturbed sample is obtained. Texas Cone Penetrometer tests were performed to evaluate the load carrying capacity of the rock encountered. These tests were performed in general accordance with test method Tex-132-E in the Texas Department of Transportation (TxDOT) Manual of Testing Procedures. The results of these tests are shown on the attached boring logs at the depths of occurrence. Field logs of the soils encountered in the borings were maintained by the drill crew. After recovery, each sample was removed for the sampler and visually classified. Representative portion of each soil sample was then wrapped in plastic and transported to our laboratory for further visual examination and laboratory testing. After completion of the drilling operations, the boreholes were backfilled with auger cuttings. 3.2 REGIONAL GEOLOGY According to the published geologic maps, the site is located within the Fluviatile Terrace Deposits and close to the contact with woodbine formation. Fluviatile Terrace soil deposits transported to the site generally lay by water instead of having been weathered from their original rock. They are often “flood plain” deposits at some of the lowest elevations in the region. Typically, water that deposits these soils first erodes portions of their original formation(s), then transports and leaves behind these types of deposits. Soils commonly found in the Fluviatile terrace deposits can vary from clays, silts and sands to coarse sands and gravels. Typically, the deposit profile has more- coarse material with depth. The clay soils found in these deposits can have high shrink/swell potential. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 5 The residual soils of the Woodbine Formation can show nonhomogeneous stratigraphy. The primary components include lean clay, Fat clay and sandy soils. The clays are typically not very thick, but they generally have a very high Shrink Swell potential. Sand and Silts can also occur in the soil profile. Very hard Sandstones, in the form of boulders and discontinuous lenses (shelf rock) and gray shale can also be encountered. As erratic as the Woodbine Formation can be, sites situated near a geologic contact zone can have even more variability. This can include variable soil conditions, to include shallow rock and rock outcropping, as well as perched groundwater conditions, sometimes with hydrostatic buildup. The location of the site on the geologic map is included in Appendix A. 3.3 SUBSURFACE CHARACTERIZATION The subsurface conditions encountered were generally consistent with published geological mapping. A summary of subsurface stratigraphy encountered in the borings is shown in Table 3.3.1. Please refer to the attached boring logs and laboratory data summary for a more detailed description of the subsurface conditions encountered in the borings. Table 3.3.1 Subsurface Stratigraphy Top of Stratum Below Grade (ft.) Bottom of Stratum Below Grade (ft.) Material Description Consistency 0 to 8 2 to 13 CLAYEY SAND (SC), brown, brownish yellow Medium Dense 0 4 to 8 LEAN CLAY (CL), dark brown, brown Very Stiff to Hard 0 to 6 4 to 8 FAT CLAY (CH), dark brown, grayish brown Very Stiff to Hard 2 8 POORLY GRADED SAND WITH CLAY and GRAVEL (SP-SC), brownish yellow Loose to Medium Dense 4 to 8 10 to 12 WELL GRADED SAND WITH CLAY and GRAVEL (SW-SC), brownish yellow Medium Dense to Very Dense 8 12 FAT CLAY (CH), dark gray, shaley Hard 10 to 13 20* SHALE, gray Rock Note: * boring termination depth 3.4 GROUNDWATER OBSERVATIONS Groundwater level observations were made in the borings during drilling operations. In drilling operations, water is not introduced into the borehole and the groundwater position can often be determined by observing water flowing into and out of the excavation. Furthermore, visual observation of soil samples retrieved can often be used in evaluating the groundwater conditions. Groundwater was encountered in the borings while drilling and at the completion of drilling. The depths of the groundwater encountered in the borings are summarized in the following table. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 6 Table 3.4.1 The Depth of Groundwater Level Boring No. During Drilling (feet) At the Completion of Drilling (feet) B-1 8 14 B-2 9 9 B-3 8 Dry B-4 8 Dry Note: Boring termination depth = 20 feet. Any water encountered in borings within this geologic setting is generally referred to as a partially perched condition. Specifically, rainfall that enters the site, either directly from overland flow or from adjacent properties, begins to percolate through surficial soils and within clay seams and fissures. This ground water flow continues downhill with the water table occasionally surfacing to form wet springs and intermittent streams. Only in the lowest lying areas and adjacent to existing creeks is a shallow groundwater table in a continuous condition. The highest groundwater observations are normally encountered in the late winter and early spring. Fluctuation in the location of the long-term water table may occur as a result of changes in precipitation, evaporation, surface water runoff and other factors not immediately apparent at the time of his investigation. Therefore, the groundwater conditions at this site are expected to be significantly influenced by surface water runoff and rainfall. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 7 4.0 LABORATORY TESTING The laboratory testing was performed by ECS on selected samples obtained during our field exploration operations. Classification and index property tests were performed on representative soil samples obtained from the test borings in order to aid in classifying soils according to the Unified Soil Classification System and to quantify and correlate engineering properties. The soil samples were tested for moisture content, Atterberg limits, minus No. 200 sieve, sieve analysis including hydrometer, and dry density. An experienced geotechnical engineer visually classified each soil sample from the test borings on the basis of texture and plasticity in accordance with the Unified Soil Classification System (USCS) and ASTM D-2488 (Description and Identification of Soils-Visual/Manual Procedures). After classification, the geotechnical engineer grouped the various soil types into the major zones noted on the boring logs in Appendix B. The group symbols for each soil type are indicated in parentheses following the soil descriptions on the boring logs. The stratification lines designating the interfaces between earth materials on the boring logs are approximate; in situ, the transitions may be gradual. The soil samples will be retained in our laboratory for a period of 60 days, after which, they will be discarded unless other instructions are received as to their disposition. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 8 5.0 FINDINGS AND RECOMMENDATIONS The following recommendations have been developed on the basis of the previously described project characteristics and subsurface conditions. 5.1 CURRENT CONDITIONS We understand the existing detention pond is unable to hold the water and is leaking through the existing plastic liner. Some exposed liners were observed in the areas of Borings B-1 and B-2. The exposed liner has generally deteriorated and cracked. The purpose of this study is to provide geotechnical information for the detention pond and provide liner recommendations for the detention pond improvements. 5.2 FINDINGS Based on the subsurface conditions encountered in the borings, on-site soils generally consist of clayey sand, poorly to well graded sand with clay and gravel, and fat to lean clays underlain by gray shale. Low permeability shale was generally encountered at depths of 10 to 13 feet below the existing grade. Sandy soils including clayey sand, poorly graded sand, and well graded sand considered as high permeability soils, were present from the existing grade to a depth of about 13 feet below the grade. These sandy soils generally do not hold the water for an extended period of time. It is our opinion that the reduced water level within the pond may have occurred through these sandy soils after the water seeps through the plastic liner. Below the sandy soils, water infiltration rate may be reduced in the clay soils and gray shale. 5.3 DETENTION POND IMPROVEMENTS Based on the borings, on-site soils can be excavated by conventional methods including using large backhoes, bulldozers, track or wheel loaders. Water seepage may be encountered during excavation. Dewatering may be necessary if significant water seepage occurs in the excavation. The groundwater should be maintained below the bottom of the excavation during construction. Permanent side slopes of 1 vertical to 3 horizontal, or flatter are recommended for the pond. Seepage losses can be controlled by the installation of relatively impermeable soil liners or high density polyethylene liners. If a polyethylene liner is used, a minimum of 12 inches of soil cover should be placed over the liner for protection. The polyethylene should be at least 12 mil thick. The type and thickness of the polyethylene liner used for the pond should be based on the design life and the requirement of the City and per liner manufacturer’s or supplier’s criteria. The liner should not be installed on windy or rainy days. If a clay liner is used, the clays used for the liner should have a Liquid Limit greater than 50 percent, Plasticity Index greater than 25 and percent passing No. 200 sieve greater than 60. They should be free of vegetation, major roots, debris, and rock greater than 4 inches. On site clays are suitable for the clay liner. The clays should be compacted to at least 95% of the Maximum Dry Density at a minimum of 2 percentage points above optimum moisture content as obtained using the Standard Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 9 Proctor Method (ASTM D-698). A minimum clay liner thickness of 2 feet is recommended. The liner should be maintained in a moist condition to prevent desiccation and shrinkage cracks. If excavations for the pond extend below the current groundwater level, a dewatering system will be required to lower the water level for placement of the liner. The pond should be filled to a level above the groundwater level prior to deactivating the dewatering system. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 10 6.0 SITE CONSTRUCTION RECOMMENDATIONS 6.1 SUBGRADE PREPARATION In a dry and undisturbed state, the upper 1-foot of the majority of the soil at the site will provide good subgrade support for fill placement and construction operations. However, when wet, this soil will degrade quickly with disturbance from contractor operations. Therefore, good site drainage should be maintained during earthwork operations, which would help maintain the integrity of the soil. The surface of the site should be kept properly graded in order to enhance drainage of the surface water away from the proposed building areas during the construction phase. We recommend that an attempt be made to enhance the natural drainage without interrupting its pattern. The soils at the site are moisture and disturbance sensitive, and contain fines which are considered moderately erodible. Therefore, the contractor should carefully plan his operation to minimize exposure of the subgrade to weather and construction equipment traffic, and provide and maintain good site drainage during earthwork operations to help maintain the integrity of the surficial soils. All erosion and sedimentation shall be controlled in accordance with sound engineering practice and current jurisdictional requirements. 6.1.2 Proofrolling After stripping and removing all unsuitable surface materials, cutting to the proposed grade, and prior to the placement of any structural fill, the exposed subgrade should be examined by the Geotechnical Engineer or authorized representative. The exposed subgrade should be thoroughly proofrolled with previously approved construction equipment having a minimum axle load of 10 tons (e.g. fully loaded tandem-axle dump truck). The areas subject to proofrolling should be traversed by the equipment in the same direction with overlapping passes of the vehicle under the observation of the Geotechnical Engineer or authorized representative. This procedure is intended to assist in identifying any localized yielding materials. In the event that unstable or “pumping” subgrade is identified by the proofrolling, those areas should be marked for repair prior to the placement of any subsequent structural fill or other construction materials. Methods of repair of unstable subgrade, such as undercutting or moisture conditioning or chemical stabilization, should be discussed with the Geotechnical Engineer to determine the appropriate procedure with regard to the existing conditions causing the instability. If the area is deemed too small for a piece of equipment to traverse the excavated area it should be thoroughly probed by the Geotechnical Engineer or authorized representative. 6.2 EARTHWORK OPERATIONS All subgrades should be scarified to a minimum depth of 6 inches, moisture conditioned and compacted to at least 95% of Maximum Dry Density as obtained by the Standard Proctor Method (ASTM D-698) moisture conditioned at or above the optimum moisture content value. All fills should be benched into the existing soils. Imported soil used for general fill should not have a Plasticity Index (PI) of greater than the material encountered onsite. Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 11 Soil moisture levels should be preserved (by various methods that can include covering with plastic, watering, etc.) until new fill, or pavements are placed. All fill soils should be placed in 8 inch loose lifts for mass grading operations and 4 inches for trench type excavations where walk behind or “jumping jack” compaction equipment is used. Upon completion of the filling operations, care should be taken to maintain the soil moisture content prior to construction of pavements. If the soil becomes desiccated, the affected material should be removed and replaced, or these materials should be scarified, moisture conditioned and recompacted. Utility cuts should not be left open for extended periods of time and should be properly backfilled. Backfilling should be accomplished with properly compacted on-site soils, rather than granular materials. If granular materials are used, a utility trench cut-off at the building line is recommended to help prevent water from migrating through the utility trench backfill to beneath the proposed structure. 6.3 MATERIAL SPECIFICATIONS This section is intended to outline the material requirements of the recommendations. 6.3.3 On-site Soil On-site soil should be free of rock fragments greater than 4 inches in size, organic matter, and other deleterious materials. Excessive large-sized clay clods should be avoided where possible or conditioned as may be necessary. We recommend that on-site soil be placed and compacted to at least 95% of the Maximum Dry Density at or above the optimum moisture content as obtained using the Standard Proctor Method (ASTM D-698). 6.3.4 Imported Clay Soil Imported clay soil if used as a clay liner should be an impermeable clay and should have a Liquid Limit greater than 50 percent, Plasticity Index greater than 25 and percent passing No. 200 sieve greater than 60. They should be free of vegetation, major roots, debris, and rock greater than 4 inches. On site clays may be suitable for the clay liner. The clays should be compacted to at least 95% of the Maximum Dry Density at a minimum of 2 percentage points above optimum moisture content as obtained using the Standard Proctor Method (ASTM D-698). Thweatt Park Detention Pond January 12, 2021 ECS Project No. 19:8140 Page 12 7.0 CLOSING ECS has prepared this report of findings, evaluations, and recommendations to guide geotechnical- related design and construction aspects of the project. The description of the proposed project is based on information provided to ECS. If any of this information is inaccurate, either due to our interpretation of the documents provided or site or design changes that may occur later, ECS should be contacted immediately in order that we can review the report in light of the changes and provide additional or alternate recommendations as may be required to reflect the proposed construction. Field observations, monitoring, and quality assurance testing during earthwork and foundation installation are an extension of and integral to the geotechnical design recommendation. We recommend that the owner retain these quality assurance services and that ECS be allowed to continue our involvement throughout these critical phases of construction to provide general consultation as issues arise. ECS is not responsible for the conclusions, opinions, or recommendations of others based on the data in this report. APPENDIX A – Figures Site Location Diagram Boring Location Diagram Regional Geology Site Location Map CoCOPPELL: THWEATT PARK POND W. Sandy Lake Rd and S. Coppell Rd, Coppell, TX TNP Engineers PE: MPB1 Project Manager: CT2 Project No.: 19:8140 Scale: Not to scale Date: 1/4/2021 Sheet 1 of 1 Boring Location Diagram CoCOPPELL: THWEATT PARK POND W. Sandy Lake Rd and S. Coppell Rd, Coppell, TX TNP Engineers PE: MPB1 Project Manager: CT2 Project No.: 19:8140 Scale: Not to scale Date: 1/4/2021 Sheet 1 of 1 Regional Geology Map CoCoppell: Thweatt Park Pond Coppell, Texas Project No. 19: 8140 PM: CT2 ECS Southwest, LLP 3033 Kellway Drive, Suite 110, Carrollton, Texas 75006 Qt (Fluviatile Terrace Deposits) Scale N/A SOURCE: Geology Atlas of Texas, Dallas Sheet, 1987 Date 1/4/2021 APPENDIX B – Field Operations Reference Notes for Boring Logs Boring Logs B-1 through B-4 REFERENCE NOTES FOR BORING LOGS MATERIAL1,2 1Classifications and symbols per ASTM D 2488-17 (Visual-Manual Procedure) unless noted otherwise. 2To be consistent with general practice, “POORLY GRADED” has been removed from GP, GP-GM, GP-GC, SP, SP-SM, SP-SC soil types on the boring logs. 3Non-ASTM designations are included in soil descriptions and symbols along with ASTM symbol [Ex: (SM-FILL)]. 4Typically estimated via pocket penetrometer or Torvane shear test and expressed in tons per square foot (tsf). 5Standard Penetration Test (SPT) refers to the number of hammer blows (blow count) of a 140 lb. hammer falling 30 inches on a 2 inch OD split spoon sampler required to drive the sampler 12 inches (ASTM D 1586). “N-value” is another term for “blow count” and is expressed in blows per foot (bpf). SPT correlations per 7.4.2 Method B and need to be corrected if using an auto hammer. 6The water levels are those levels actually measured in the borehole at the times indicated by the symbol. The measurements are relatively reliable when augering, without adding fluids, in granular soils. In clay and cohesive silts, the determination of water levels may require several days for the water level to stabilize.In such cases, additional methods of measurement are generally employed. 7Minor deviation from ASTM D 2488-17 Note 14. 8Percentages are estimated to the nearest 5% per ASTM D 2488-17. Reference Notes for Boring Logs (10-14-2020).doc © 2020 ECS Corporate Services, LLC. All Rights Reserved COHESIVE SILTS & CLAYS UNCONFINED COMPRESSIVE STRENGTH, QP4 <0.25 0.25 - <0.50 0.50 - <1.00 1.00 - <2.00 2.00 - <4.00 4.00 - 8.00 >8.00 SPT5 (BPF) CONSISTENCY7 (COHESIVE) GRAVELS, SANDS & NON-COHESIVE SILTS SPT5 DENSITY <5 5 - 10 11 - 30 31 - 50 >50 Very Loose Loose Medium Dense Dense Very Dense WATER LEVELS6 RELATIVE AMOUNT7 Trace With Adjective (ex: “Silty”) COARSE GRAINED (%)8 <5 FINE GRAINED (%)8 <5 DRILLING SAMPLING SYMBOLS & ABBREVIATIONS PARTICLE SIZE IDENTIFICATION DESIGNATION PARTICLE SIZES Hollow Stem Auger Power Auger (no sample) Bulk Sample of Cuttings Wash Sample Shelby Tube Sampler Split Spoon Sampler Rock Quality Designation % Rock Sample Recovery % Rock Core, NX, BX, AX Rock Bit Drilling Pressuremeter TestSS ST WS BS PA HSA RQD PM RD RC REC Boulders Cobbles Gravel: Sand: Silt & Clay (“Fines”) Fine Medium Coarse Fine Coarse 0.074 mm to 0.425 mm (No. 200 to No. 40 sieve) <0.074 mm (smaller than a No. 200 sieve) 0.425 mm to 2.00 mm (No. 40 to No. 10 sieve) 2.00 mm to 4.75 mm (No. 10 to No. 4 sieve) 4.75 mm to 19 mm (No. 4 sieve to ¾ inch) ¾ inch to 3 inches (19 mm to 75 mm) 3 inches to 12 inches (75 mm to 300 mm) 12 inches (300 mm) or larger >50 31 - 50 16 - 30 9 - 15 5 - 8 3 - 4 <3 Very Hard Hard Very Stiff Stiff Firm Soft Very Soft ASPHALT CONCRETE GRAVEL TOPSOIL VOID BRICK AGGREGATE BASE COURSE GW GP GM GC SW SP SM SC ML MH CL CH OL OH PT WELL-GRADED GRAVEL gravel-sand mixtures, little or no fines POORLY-GRADED GRAVEL gravel-sand mixtures, little or no fines SILTY GRAVEL gravel-sand-silt mixtures CLAYEY GRAVEL gravel-sand-clay mixtures WELL-GRADED SAND gravelly sand, little or no fines POORLY-GRADED SAND gravelly sand, little or no fines SM SILTY SAND sand-silt mixtures CLAYEY SAND sand-clay mixtures SILT non-plastic to medium plasticity ELASTIC SILT high plasticity LEAN CLAY low to medium plasticity FAT CLAY high plasticity ORGANIC SILT or CLAY non-plastic to low plasticity ORGANIC SILT or CLAY high plasticity PEAT highly organic soils WL (First Encountered) WL (Completion) WL (Seasonal High Water) WL (Stabilized) FILL POSSIBLE FILL PROBABLE FILL ROCK FILL AND ROCK 25 - 45 10 - 20 30 - 45 10 - 25 DEPTH (FT)5 10 15 20 25 30 SAMPLE NUMBERS-1 S-2 S-3 S-4 S-5 S-6 S-7 SAMPLE TYPEST ST SS SS SS TCP TCP SAMPLE DIST. (IN)24 24 6 18 18 3 3 RECOVERY (IN)24 24 6 18 18 DESCRIPTION OF MATERIAL (CL) LEAN CLAY, brown and dark brown, moist, very sƟī to hard, with gravel and sand (SW-SC) WELL GRADED SAND WITH CLAY AND GRAVEL, brownish yellow, moist, medium dense to very dense SHALE, Gray END OF DRILLING AT 20.0 FT WATER LEVELSELEVATION (FT)486 481 476 471 466 BLOWS/6"(N -Value)50/6" (50/6") 4-6-8 (14) 14-35-40 (75) PlasƟc Limit Water Content Liquid Limit X─────────⚫─────────△ 3.25 4.50 50/6" 14 75 25 24 15 13 8.9 3.1 9.5 100/ 2.75" 100/ 2.75" CLIENT: TNP Engineers PROJECT NAME: CoCoppell: ThweaƩ Park Pond PROJECT NO.:BORING NO.:SHEET: 19:8140 B-1 1 of 1 DRILLER/CONTRACTOR: StrataBore, LLC SITE LOCATION: W. Sandy Lake Road and S. Coppell Road, Coppell, Texas 75019 LOSS OF CIRCULATION NORTHING: 7038906.6 EASTING: 2426286.3 STATION:SURFACE ELEVATION: 491.0 BOTTOM OF CASING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES. IN -SITU THE TRANSITION MAY BE GRADUAL WL (First Encountered) WL (CompleƟon) WL (Seasonal High Water) WL (Stabilized) 8.00 14.00 N/A N/A BORING STARTED: BORING COMPLETED: EQUIPMENT: Truck Dec 03 2020 Dec 03 2020 LOGGED BY: StrataBore CAVE IN DEPTH: HAMMER TYPE: DRILLING METHOD: Auto CFA GEOTECHNICAL BOREHOLE LOG STANDARD PENETRATION BLOWS/FT ROCK QUALITY DESIGNATION & RECOVERY RQD ـــــــــــ REC CALIBRATED PENETROMETER TON/SF TEXAS CONE PENETRATION BLOWS/FT DEPTH (FT)5 10 15 20 25 30 SAMPLE NUMBERS-1 S-2 S-3 S-4 S-5 S-6 S-7 SAMPLE TYPEST SS SS SS SS TCP TCP SAMPLE DIST. (IN)24 18 18 18 18 3 2 RECOVERY (IN)24 18 18 18 18 DESCRIPTION OF MATERIAL (SC) CLAYEY SAND, brown, moist, with clay layers (SP-SC) POORLY GRADED SAND WITH CLAY AND GRAVEL, brownish yellow, moist, loose to medium dense (SW-SC) WELL GRADED SAND WITH CLAY AND GRAVEL, brownish yellow, moist, medium dense SHALE, Gray END OF DRILLING AT 20.0 FT WATER LEVELSELEVATION (FT)486 481 476 471 466 BLOWS/6"(N -Value)1-2-2 (4) 4-5-8 (13) 6-8-12 (20) 5-12-15 (27) PlasƟc Limit Water Content Liquid Limit X─────────⚫─────────△ 2.00 4 13 20 27 24 24 13 14 11.7 4.2 4.6 10.0 100/ 3.25" 100/ 2.00" CLIENT: TNP Engineers PROJECT NAME: CoCoppell: ThweaƩ Park Pond PROJECT NO.:BORING NO.:SHEET: 19:8140 B-2 1 of 1 DRILLER/CONTRACTOR: StrataBore, LLC SITE LOCATION: W. Sandy Lake Road and S. Coppell Road, Coppell, Texas 75019 LOSS OF CIRCULATION NORTHING: 7038916.0 EASTING: 2426186.8 STATION:SURFACE ELEVATION: 491.0 BOTTOM OF CASING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES. IN -SITU THE TRANSITION MAY BE GRADUAL WL (First Encountered) WL (CompleƟon) WL (Seasonal High Water) WL (Stabilized) 9.00 9.00 N/A N/A BORING STARTED: BORING COMPLETED: EQUIPMENT: Truck Dec 03 2020 Dec 03 2020 LOGGED BY: StrataBore CAVE IN DEPTH: HAMMER TYPE: DRILLING METHOD: Auto CFA GEOTECHNICAL BOREHOLE LOG STANDARD PENETRATION BLOWS/FT ROCK QUALITY DESIGNATION & RECOVERY RQD ـــــــــــ REC CALIBRATED PENETROMETER TON/SF TEXAS CONE PENETRATION BLOWS/FT DEPTH (FT)5 10 15 20 25 30 SAMPLE NUMBERS-1 S-2 S-3 S-4 S-5 S-6 S-7 SAMPLE TYPEST ST SS SS SS TCP TCP SAMPLE DIST. (IN)24 24 18 18 18 12 1 RECOVERY (IN)24 24 18 18 18 DESCRIPTION OF MATERIAL (CH) FAT CLAY, dark brown, moist, hard (SC) CLAYEY SAND, brownish yellow, moist, medium dense, with gravel (CH) FAT CLAY, grayish brown, moist, very sƟī (CH) FAT CLAY, dark gray, moist, shaley, hard SHALE, Gray END OF DRILLING AT 20.0 FT WATER LEVELSELEVATION (FT)481 476 471 466 461 BLOWS/6"(N -Value)8-12-16 (28) 6-9-11 (20) 8-20-30 (50) PlasƟc Limit Water Content Liquid Limit X─────────⚫─────────△ 4.50 4.50 28 20 50 68 84 69 25 28 29 19.5 6.6 31.3 19.8 69 100/ 1.50" CLIENT: TNP Engineers PROJECT NAME: CoCoppell: ThweaƩ Park Pond PROJECT NO.:BORING NO.:SHEET: 19:8140 B-3 1 of 1 DRILLER/CONTRACTOR: StrataBore, LLC SITE LOCATION: W. Sandy Lake Road and S. Coppell Road, Coppell, Texas 75019 LOSS OF CIRCULATION NORTHING: 7039063.8 EASTING: 2426183.6 STATION:SURFACE ELEVATION: 486.0 BOTTOM OF CASING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES. IN -SITU THE TRANSITION MAY BE GRADUAL WL (First Encountered) WL (CompleƟon) WL (Seasonal High Water) WL (Stabilized) 8.00 Dry N/A N/A BORING STARTED: BORING COMPLETED: EQUIPMENT: Truck Dec 03 2020 Dec 03 2020 LOGGED BY: StrataBore CAVE IN DEPTH: HAMMER TYPE: DRILLING METHOD: Auto CFA GEOTECHNICAL BOREHOLE LOG STANDARD PENETRATION BLOWS/FT ROCK QUALITY DESIGNATION & RECOVERY RQD ـــــــــــ REC CALIBRATED PENETROMETER TON/SF TEXAS CONE PENETRATION BLOWS/FT DEPTH (FT)5 10 15 20 25 30 SAMPLE NUMBERS-1 S-2 S-3 S-4 S-5 S-6 S-7 SAMPLE TYPEST ST ST ST SS TCP TCP SAMPLE DIST. (IN)24 24 24 24 18 10 9 RECOVERY (IN)24 24 24 24 18 DESCRIPTION OF MATERIAL (CL) LEAN CLAY, dark brown, brown, moist, hard (SC) CLAYEY SAND, brown and brownish yellow, moist, medium dense, with gravel SHALE, Gray END OF DRILLING AT 20.0 FT WATER LEVELSELEVATION (FT)481 476 471 466 461 BLOWS/6"(N -Value)8-9-12 (21) PlasƟc Limit Water Content Liquid Limit X─────────⚫─────────△ 4.50 4.50 4.50 4.50 21 40 37 15 14 18.5 9.6 13.3 74/ 10.50" 100/ 9.50" CLIENT: TNP Engineers PROJECT NAME: CoCoppell: ThweaƩ Park Pond PROJECT NO.:BORING NO.:SHEET: 19:8140 B-4 1 of 1 DRILLER/CONTRACTOR: StrataBore, LLC SITE LOCATION: W. Sandy Lake Road and S. Coppell Road, Coppell, Texas 75019 LOSS OF CIRCULATION NORTHING: 7039003.7 EASTING: 2426328.5 STATION:SURFACE ELEVATION: 486.0 BOTTOM OF CASING THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES. IN -SITU THE TRANSITION MAY BE GRADUAL WL (First Encountered) WL (CompleƟon) WL (Seasonal High Water) WL (Stabilized) 8.00 Dry N/A N/A BORING STARTED: BORING COMPLETED: EQUIPMENT: Truck Dec 03 2020 Dec 03 2020 LOGGED BY: CAVE IN DEPTH: HAMMER TYPE: DRILLING METHOD: Auto CFA GEOTECHNICAL BOREHOLE LOG STANDARD PENETRATION BLOWS/FT ROCK QUALITY DESIGNATION & RECOVERY RQD ـــــــــــ REC CALIBRATED PENETROMETER TON/SF TEXAS CONE PENETRATION BLOWS/FT APPENDIX C – Laboratory Testing Laboratory Testing Summary Particle Size Distribution Results ECS Southwest, LLPCarrollton, TexasDate: 1/4/2021Project No: 19:8140 Project Name: CoCoppell: Thweatt Park PondProject Engineer: CT2 Principal Engineer: MPB1LL PL PIB-1S10 - 28.9CL25151052.7 102.8S3 4 - 4.5 3.1 SW-SC8.9 S5 8 - 9.5 9.5 SW-SC 241311 7.0 B-2 S1 0 - 2 11.742.3 S2 2 - 3.5 4.210.4 S3 4 - 5.5 4.6 SP-SC 241311 11.2 S5 8 - 9.5 10.0 SW-SC 241410 7.4 B-3 S2 2 - 4 19.5 CH 682543 112.4S3 4 - 5.5 6.621.4 S4 6 - 7.5 31.3 CH 842856 74.3 S5 8 - 9.5 19.8 CH 692940 92.9 B-4 S1 0 - 2 18.581.9 S3 4 - 6 9.6 CL 401525 60.1 S5 8 - 9.5 13.3 SC 371423 18.4 Notes:1. ASTM D 2216, 2. ASTM D 2487, 3. ASTM D 4318, 4. ASTM D 422, and 5. ASTM D 2937Definitions:MC: Moisture Content, Soil Type: USCS (Unified Soil Classification System), LL: Liquid Limit, PL: Plastic Limit, PI: Plasticity Index, NP: Non PlasticBoring NumberSample NumberDepth (feet)Soil Type2Percent Passing No. 200 Sieve4Atterberg Limits3Laboratory Testing SummaryDry Unit Weight5 (pcf)MC1 ( % )Summary By: RS9Page 1 of 1 D90 D50 D10 D85 D30 Cu D60 D15 Cc PARTICLE SIZE DISTRIBUTION TEST RESULTS () Sieving Specification Envelope Name:Particle Size % Passing Sieve Size Particle Size % passing % Lower limit % Upper Limit In/Out Variance1 1/2"100.0 3/4"100.0 -2.15E+09 ########3/8"100.0 #4 100.0 -2.15E+09 #########10 100.0 #40 97.6 -2.15E+09 #########60 75.7 #100 66.2 -2.15E+09 #########200 52.7 -2.15E+09 ######## -2.15E+09 ######## -2.15E+09 ######## USCS Liquid Limit 25 0.354 0.072 0.042 AASHTO A-4 Plastic Limit 15 0.313 0.055 2.621 USCS Group Name Plasticity Index 10 0.109 0.045 0.662 Project:CoCoppell_ Thweatt Park Pond Project No.:19:8140 Depth (ft):0 - 2 Client:TNP Engineers Sample No.:S-1 Sample Source:B-1 Date Reported: Office / Lab Address Office Number / Fax ECS Southwest LLP - Dallas 3033 Kellway Drive Suite 110 Carrollton, TX 75006 (972)392-3222 (214)483-9684 Tested by Checked by Approved by Date Received Remarks ÷÷ ø ö çç è æ 1m m SILTSAND FineMediumCoarseGRAVEL CLAYVery Coarse 3"2"1.5"1"3/4"1/2"3/8"#4 #10 #20 #40 #60 #100 #140 #200 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percentage Passing %Particle Size mm D90 D50 D10 D85 D30 Cu D60 D15 Cc PARTICLE SIZE DISTRIBUTION TEST RESULTS () Sieving Specification Envelope Name:Particle Size % Passing Sieve Size Particle Size % passing % Lower limit % Upper Limit In/Out Variance1 1/2"100.0 3/4"93.8 -2.15E+09 ########3/8"78.8 #4 58.7 -2.15E+09 #########10 36.8 #40 18.0 -2.15E+09 #########60 13.0 #100 9.0 -2.15E+09 #########200 7.0 -2.15E+09 ######## -2.15E+09 ######## -2.15E+09 ######## USCS Liquid Limit 24 15.940 3.369 0.170 AASHTO A-2-6 Plastic Limit 13 12.652 1.142 29.148 USCS Group Name Plasticity Index 11 4.968 0.309 1.541 Project:CoCoppell_ Thweatt Park Pond Project No.:19:8140 Depth (ft):8 - 9.5 Client:TNP Engineers Sample No.:S-5 Sample Source:B-1 Date Reported: Office / Lab Address Office Number / Fax ECS Southwest LLP - Dallas 3033 Kellway Drive Suite 110 Carrollton, TX 75006 (972)392-3222 (214)483-9684 Tested by Checked by Approved by Date Received Remarks ÷÷ ø ö çç è æ 1m m SILTSAND FineMediumCoarseGRAVEL CLAYVery Coarse 3"2"1.5"1"3/4"1/2"3/8"#4 #10 #20 #40 #60 #100 #140 #200 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percentage Passing %Particle Size mm D90 D50 D10 D85 D30 Cu D60 D15 Cc PARTICLE SIZE DISTRIBUTION TEST RESULTS () Sieving Specification Envelope Name:Particle Size % Passing Sieve Size Particle Size % passing % Lower limit % Upper Limit In/Out Variance1 1/2"100.0 3/4"100.0 -2.15E+09 ########3/8"96.6 #4 90.6 -2.15E+09 #########10 78.3 #40 53.0 -2.15E+09 #########60 33.4 #100 16.9 -2.15E+09 #########200 11.2 -2.15E+09 ######## -2.15E+09 ######## -2.15E+09 ######## USCS Liquid Limit 24 4.554 0.392 0.000 AASHTO A-2-6 Plastic Limit 13 3.204 0.225 0.000 USCS Group Name Plasticity Index 11 0.652 0.119 0.000 Project:CoCoppell_ Thweatt Park Pond Project No.:19:8140 Depth (ft):4 - 5.5 Client:TNP Engineers Sample No.:S-3 Sample Source:B-2 Date Reported: Office / Lab Address Office Number / Fax ECS Southwest LLP - Dallas 3033 Kellway Drive Suite 110 Carrollton, TX 75006 (972)392-3222 (214)483-9684 Tested by Checked by Approved by Date Received Remarks ÷÷ ø ö çç è æ 1m m SILTSAND FineMediumCoarseGRAVEL CLAYVery Coarse 3"2"1.5"1"3/4"1/2"3/8"#4 #10 #20 #40 #60 #100 #140 #200 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percentage Passing %Particle Size mm D90 D50 D10 D85 D30 Cu D60 D15 Cc PARTICLE SIZE DISTRIBUTION TEST RESULTS () Sieving Specification Envelope Name:Particle Size % Passing Sieve Size Particle Size % passing % Lower limit % Upper Limit In/Out Variance1 1/2"100.0 3/4"100.0 -2.15E+09 ########3/8"88.7 #4 65.1 -2.15E+09 #########10 42.5 #40 20.9 -2.15E+09 #########60 14.2 #100 9.6 -2.15E+09 #########200 7.4 -2.15E+09 ######## -2.15E+09 ######## -2.15E+09 ######## USCS Liquid Limit 24 10.289 2.665 0.157 AASHTO A-2-4 Plastic Limit 14 8.522 0.816 24.919 USCS Group Name Plasticity Index 10 3.908 0.266 1.087 Project:CoCoppell_ Thweatt Park Pond Project No.:19:8140 Depth (ft):8 - 9.5 Client:TNP Engineers Sample No.:S-5 Sample Source:B-2 Date Reported: Office / Lab Address Office Number / Fax ECS Southwest LLP - Dallas 3033 Kellway Drive Suite 110 Carrollton, TX 75006 (972)392-3222 (214)483-9684 Tested by Checked by Approved by Date Received Remarks ÷÷ ø ö çç è æ 1m m SILTSAND FineMediumCoarseGRAVEL CLAYVery Coarse 3"2"1.5"1"3/4"1/2"3/8"#4 #10 #20 #40 #60 #100 #140 #200 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percentage Passing %Particle Size mm D90 D50 D10 D85 D30 Cu D60 D15 Cc PARTICLE SIZE DISTRIBUTION TEST RESULTS () Sieving Specification Envelope Name:Particle Size % Passing Sieve Size Particle Size % passing % Lower limit % Upper Limit In/Out Variance1 1/2"100.0 3/4"100.0 -2.15E+09 ########3/8"98.9 #4 97.1 -2.15E+09 #########10 96.0 #40 88.0 -2.15E+09 #########60 86.7 #100 80.7 -2.15E+09 #########200 74.3 -2.15E+09 ######## -2.15E+09 ######## -2.15E+09 ######## USCS Liquid Limit 84 0.626 0.005 0.000 AASHTO A-7-6 Plastic Limit 28 0.216 0.001 0.000 USCS Group Name Plasticity Index 56 0.026 0.000 0.000 Project:CoCoppell_ Thweatt Park Pond Project No.:19:8140 Depth (ft):6 - 7.5 Client:TNP Engineers Sample No.:S-4 Sample Source:B-3 Date Reported: Office / Lab Address Office Number / Fax ECS Southwest LLP - Dallas 3033 Kellway Drive Suite 110 Carrollton, TX 75006 (972)392-3222 (214)483-9684 Tested by Checked by Approved by Date Received Remarks ÷÷ ø ö çç è æ 1m m SILTSAND FineMediumCoarseGRAVEL CLAYVery Coarse 3"2"1.5"1"3/4"1/2"3/8"#4 #10 #20 #40 #60 #100 #140 #200 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percentage Passing %Particle Size mm D90 D50 D10 D85 D30 Cu D60 D15 Cc PARTICLE SIZE DISTRIBUTION TEST RESULTS () Sieving Specification Envelope Name:Particle Size % Passing Sieve Size Particle Size % passing % Lower limit % Upper Limit In/Out Variance1 1/2"100.0 1"100.0 -2.15E+09 ########3/4"100.0 3/8"100.0 -2.15E+09 #########4 99.6 #10 98.9 -2.15E+09 #########40 95.2 #60 87.3 -2.15E+09 #########100 72.6 #200 60.1 -2.15E+09 ######## -2.15E+09 ######## -2.15E+09 ######## USCS Liquid Limit 40 0.300 0.064 0.034 AASHTO A-6 Plastic Limit 15 0.231 0.047 2.196 USCS Group Name Plasticity Index 25 0.075 0.037 0.854 Project:CoCoppell_ Thweatt Park Pond Project No.:19:8140 Depth (ft):4 - 6 Client:TNP Engineers Sample No.:S-3 Sample Source:B-4 Date Reported: Office / Lab Address Office Number / Fax ECS Southwest LLP - Dallas 3033 Kellway Drive Suite 110 Carrollton, TX 75006 (972)392-3222 (214)483-9684 Tested by Checked by Approved by Date Received Remarks ÷÷ ø ö çç è æ 1m m SILTSAND FineMediumCoarseGRAVEL CLAYVery Coarse 3"2"1.5"1"3/4"1/2"3/8"#4 #10 #20 #40 #60 #100 #140 #200 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percentage Passing %Particle Size mm