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HomeMy WebLinkAboutSW3210101_900-2022.62 Geotechnical Report for Glencroft Phase 2_20210324CE'LEBRATING 15 ye4als& UMMIT ENGINEERING, LABORATORY & TESTING, P.C. REPORT OF GEOTECHNICAL SUBSURFACE EXPLORATION GLENCROFT - PHASE 2 GLENCROFT DRIVE WINGATE, NORTH CAROLINA SUMMIT PROJECT NO. 2022.62 Prepared For: Mr. Keith E. Fenn, PE True Homes 2649 Brekonridge Centre Drive Monroe, North Carolina 28110 Email: Kfenn(? ,truehomesusa.com Prepared By: SUMMIT Engineering, Laboratory & Testing, P. C. (SUMMIT) 3575 Centre Circle Drive Fort Mill, South Carolina 29715 October 18, 2019 ENGINEERING 16 LABORATORY* TESTING 3575 Centre Circle Drive I Fort Mill, South Carolina 29715 1 (704) 504 - 1717 1 (704) 504 - 1125 (Fax) WWW.SUMMIT-COMPANIES.COM CIFLE13RATING 15 YE4RS SUMMIT ENGINEERING, LABORATORY &TESTING, P.C. October 18, 2019 Mr. Keith E. Fenn, PE True Homes 2649 Brekonridge Centre Drive Monroe, North Carolina 28110 Email: Kfenngtruehomesusa.com Subj ect: Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 Glencroft Drive Wingate, North Carolina SUNUMT Project No. 2022.62 Dear Mr. Fenn: SUMMIT Engineering, Laboratory & Testing, P. C. (SUNUMT) has completed a geotechnical subsurface exploration for the Glencroft - Phase 2 site located in Wingate, North Carolina. This geotechnical subsurface exploration was performed in general accordance with our Proposal No. P2019-1 011 -G, dated August 27, 2019. This report contains a brief description of the project information provided to us, general site and subsurface conditions revealed during our geotechnical subsurface exploration and our general recommendations regarding foundation design and construction. SUNMUT appreciates the opportunity to be of service to you on this project. If you have any questions concerning the information presented herein or if we can be of further assistance, please feel free to call us at (704) 504-1717. Sincerely yours, SUNMUT Engineering, Laboratory & Testing, P. C. .'�\0�11110flll /// I I r\ \A CAyC) . ................ X SUMMIT*%.. -z- Engineering, Laboratory & LU Testing, P.C. z C-4361 ........... PE OF "1111110" �\\\\ 60"119"o \A CA 9.(-/ 2-3055 1 1' 10/18/19 if �A. C Coo ' 0, Todd A. Costner, E.I. Kerry C. Cooper, P.E. Senior Professional Geotechnical Department Manager Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 TABLE OF CONTENTS SECTION Page EXECUTIVE SUMMARY ........................................................................................................... ill 1.0 INTRODUCTION .............................................................................................................. I I.I. Site and Project Description .................................................................................... 1 1.2. Purpose of Subsurface Exploration ......................................................................... 1 2.0 EXPLORATION PROCEDURES ...................................................................................... 3 2.1. Field Exploration .................................................................................................... 3 3.0 AREA GEOLOGY AND SUBSURFACE CONDITIONS ............................................... 4 3.1. Physiography and Area Geology ............................................................................ 4 3.2. Generalized Subsurface Stratigraphy ...................................................................... 4 3.2.1. Surface Materials ........................................................................................ 5 3.2.2. Existing Fill Soils ....................................................................................... 5 3.2.3. Residual Soils ............................................................................................. 6 3.2.4. Partially Weathered Rock and Auger Refusal ............................................ 6 3.2.5. Groundwater Level Measurements ............................................................ 7 4.0 EVALUATIONS AND RECOMMENDATIONS ............................................................. 8 4.1. General .................................................................................................................... 8 4.2. Shallow Foundation Recommendations ................................................................. 8 4.3. Retaining Wall Recommendations ......................................................................... 9 4.4. Low to Moderate Plasticity Moisture Sensitive Soils (CL) .................................. 10 4.5. High Plasticity Moisture Sensitive Soils (CH) ..................................................... 11 4.6. Wet Weather Conditions ....................................................................................... 12 4.7. Floor Slabs ............................................................................................................ 13 4.8. Pavements Subgrade Preparation .......................................................................... 13 4.9. Cut and Fill Slopes ................................................................................................ 14 5.0 CONSTRUCTION CONSIDERATIONS ........................................................................ 15 5.1. Abandoned Utilities/Structures ............................................................................. 15 5.2. Site Preparation ..................................................................................................... 15 5.3. Difficult Excavation .............................................................................................. 16 5.4. Temporary Excavation Stability ........................................................................... 18 5.5. Structural Fill ........................................................................................................ 18 5.6. Suitability of Excavated Soils for Re -Use ............................................................ 19 5.7. Engineering Services During Construction .......................................................... 20 6.0 RELIANCE AND QUALIFICATIONS OF REPORT .................................................... 21 APPENDIX 1 - Figures SiteVicinity Map ................................................................................................................. I BoringLocation Plan ........................................................................................................... 2 APPENDIX 2 - Boring Logs M Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 EXECUTIVE SUMMARY SUMMIT has completed a geotechnical subsurface exploration for the Glencroft - Phase 2 project. The purpose of this exploration was to obtain general information regarding the subsurface conditions and to provide geotechnical recommendations regarding foundation support of the proposed construction. The exploration consisted of twelve (12) soil test borings (identified as B- I through B-12). The approximate test locations are shown on the Figure 2 provided in Appendix 1. The following geotechnical engineering information was obtained as a result of the soil test borings: Surface Materials — Surficial organic (topsoil) soils were observed at the existing ground surface of the borings with thicknesses ranging from approximately I to 4 inches. Existing Fill Soils - Existing fill (disturbed) soils were encountered beneath the surface materials in Boring B-2 to approximate depth of 22 feet below the existing ground surface. Boring B-2 was located on top of an existing stockpile. When sampled, the existing fill soils generally consisted of fat clays (CH), lean clays (CL), and sandy silts (ML) with rock fragments and rocks. The Standard Penetration Resistances (SPT N-values) in the existing fill soils ranged from 17 to 36 blows per foot (bpf). Residual Soils - Residual (undisturbed) soils were encountered below the surface materials and/or existing fill soils and extended to either the maximum termination depth or partially weathered rock (PWR). These residual soils generally consisted of fat clays (CH), lean clays (CL), and sandy silts (ML) with varying amount rock fragments. The Standard Penetration Resistances (SPT N-values) in the residual soils ranged from 16 to greater than 50 bpf. Partially Weathered Rock (PWR) and Auger Refusal — Partially weathered rock (PWR) conditions were encountered in all of the borings at approximate depths beginning near the existing ground surface to 22 feet below the existing ground surface. Auger refusal conditions were encountered in ten (10) of the borings at approximate depths ranging from 6.1 to 28.6 feet. Groundwater Levels - At the time of drilling, groundwater was not observed in the borings. After waiting more than 24 hours, water level was observed in Boring B-12 at an approximate depth of 7 feet below the existing ground surface. Foundation Support - Based on the results of our borings, the proposed structures can be adequately supported on shallow foundations systems provided site preparation and compacted fill recommendation procedures outlined in this report are implemented concerning unsuitable soils such as fat clays. An allowable net bearing pressure of up to 3,000 pounds per square foot (psf) can be used for design of the foundations bearing on approved undisturbed residual soils, or on structural fill compacted to at least 95 percent of its Standard Proctor maximum dry density. iii Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 SUMNHT Project No. 2022.62 October 18, 2019 Special Construction Considerations: Special considerations are warranted concerning existing fill soils, fat clays, and the removal of PWR and auger refusal materials. o Existing Fill Soils: At the time of this report, no relevant information (documentations) regarding previous grading activities, prior materials testing, and/or geotechnical engineering services was provided for our review. Boring B-2 encountered undocumented fill soils (fill soils not monitored and tested during placement) and undocumented fill poses risks associated with undetected deleterious materials within the fill soils and/or deleterious material at the interface between the fill soils and residual soils. As previously mentioned, Boring B-2 was located on an existing stockpile. We recommend additional testing such as, but not limited to, test pit excavations be performed in order to further evaluate these soil conditions and contents. Should unsuitable soils be encountered, these soils should be evaluated in the field by a Geotechnical Engineer -of -Record and/or his designee prior to remediation. o Fat Clas: High plasticity and moisture sensitive (fat clays) soils were encountered in Borings B-2, B-6 and B-8 at various depths. Highly plastic soils can undergo significant changes in volume (shrink/swell behavior) with changes in moisture conditions. These soils typically provide poor subgrade support for pavements and foundations. o Difficult Excavation: The result of the borings indicated that the excavation of residual soils is possible with conventional excavating techniques. However, please note that partially weathered rock (PWR) conditions were encountered in all of the borings and auger refusal conditions were encountered in ten (10) of the borings performed for this exploration. Dependent on final grades and locations, the contractor should anticipate the excavations of PWR and auger refusal conditions will require specialized equipment and procedures. Please note that the information provided in this executive summary is intended to be a brief overview of project information and recommendations from the geotechnical report. The information in the executive summary should not be used without first reading the geotechnical report and the recommendations described therein. iv Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 1.0 INTRODUCTION I.I. Site and Project Description The subject site located off of Glencroft Drive in Wingate, North Carolina. A vicinity map showing the project's general location is provided as Figure 1. The subject property is approximately 46.95 acres comprised of Union County Tax Parcel ID Number 02239083. At the time of our field exploration, the subject site was wooded and undeveloped land with a large stockpile. The Client (True Homes) provided SUMMIT a plan sheet titled "Rezoning Overall Site Plan", prepared by The John R. McAdams Company, Inc. dated July 24, 2019 that indicated the configurations of the proposed construction planned for this project. Based on the provided information, we understand the project is planned to include residential buildings, paved roadways, and a best -management -practice (BMP) pond. At the time of report preparation, SUMMIT had not been provided structural details of the planned construction indicating proposed loads, foundation bearing elevations, or finished floor elevations. For this report, SUMMIT assumed the proposed structures will be supported on a shallow foundation system consisting of spread, strip, and/or combined footings and that wall loads will be on the order of I to 3 kips per foot. Also, grading plans were not available at the time of this report and we have assumed that maximum cut/fill depths will be on the order of I to 3 feet over the existing ground surface. 1.2. Purpose of Subsurface Exploration The purpose of this exploration was to obtain general geotechnical information regarding the subsurface conditions and to provide general preliminary recommendations regarding the geotechnical aspects of site preparation and foundation design. This report contains the following items: 0 General subsurface conditions, I Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 SUMNHT Project No. 2022.62 October 18, 2019 • Boring logs and an approximate "Boring Location Plan", • Suitable foundation types, • Allowable bearing pressures for design of shallow foundations, • Anticipated excavation difficulties during site grading and/or utility installation, • Remedial measures to correct unsatisfactory soil conditions during site development, as needed, 0 Drainage requirements around structures and under floor slabs, as needed, 0 Construction considerations, 0 Pavement subgrade support guidelines. Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 2.0 EXPLORATION PROCEDURES 2.1. Field Exploration SUMMIT visited the site on October 7 and 8, 2019 and performed a geotechnical exploration that consisted of twelve (12) soil test borings (identified as B-1 through B-12). The approximate locations of the borings are shown on the Figure 2 - "Boring Location Plan" provided in Appendix 1. The borings were located by professionals from our office using the provided plan, recreation - grade handheld GPS, existing topography, and aerial maps as reference. Since the boring locations were not surveyed, the location of the borings should be considered approximate. The soil test borings were performed using a Diedrich D50 drill rig and extended to approximate depths of 6.1 to 28.6 feet below the existing ground surface. Hollow -stem, continuous flight auger drilling techniques were used to advance the borings into the ground. Standard Penetration Tests (SPT) were performed within the mechanical borings at designated intervals in general accordance with ASTM D 1586. The SPT "N" value represents the number of blows required to drive a split - barrel sampler 12 inches with a 140-pound hammer falling from a height of 30 inches. When properly evaluated, the SPT results can be used as an index for estimating soil strength and density. In conjunction with the penetration testing, representative soil samples were obtained from each test location and returned to our laboratory for visual classification in general accordance with ASTM D 2488. Water level measurements were attempted at the termination of drilling. The results of these tests are presented on the individual boring logs provided in Appendix 2 at the respective test depth. 3 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 3.0 AREA GEOLOGY AND SUBSURFACE CONDITIONS 3.1. Physiography and Area Geology The subject property is located in Wingate, North Carolina, which is located in the south central Piedmont Physiographic Province. The Piedmont Province generally consists of well-rounded hills and ridges which are dissected by a well -developed system of draws and streams. The Piedmont Province is predominantly underlain by metamorphic rock (formed by heat, pressure and/or chemical action) and igneous rock (formed directly from molten material) which were initially formed during the Precambrian and Paleozoic eras. The volcanic and sedimentary rocks deposited in the Piedmont Province during the Precambrian era were the host of the metamorphism and were generally changed to gneiss and schist. The more recent Paleozoic era had periods of igneous emplacement, with episodes of regional metamorphism resulting in the majority of the rock types seen today. The topographic relief found throughout the Piedmont Province has developed from differential weathering of theses igneous and metamorphic rock formations. Ridges developed along the more easily weathered and erodible rock. Because of the continued chemical and physical weathering, the rocks in the Piedmont Province are generally covered with a mantle of soil that has weathered in -place from the parent bedrock below. These soils have variable thicknesses and are referred to as residual soils, as they are the result of in -place weathering. Residual soils are typically fine- grained and have a higher clay content near the ground surface because of the advanced weathering. Similarly, residual soils typically become more coarse -grained with increasing depth because of decreased weathering. As weathering decreases with depth, residual soils generally retain the overall appearance, texture, gradation and foliations of their parent rock. 3.2. Generalized Subsurface Stratigraphy General subsurface conditions observed during our geotechnical exploration are described herein For more detailed soil descriptions and stratifications at a particular field test location, the respective "Boring Logs", provided in Appendix 2 should be reviewed. The horizontal 4 Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 SUMNHT Project No. 2022.62 October 18, 2019 stratification lines designating the interface between various strata represent approximate boundaries. Transitions between different strata in the field may be gradual in both the horizontal and vertical directions. Therefore, subsurface stratigraphy between test locations may vary. 3.2.1. Surface Materials Surficial organic (topsoil) soils were observed in all borings at the existing ground surface with thicknesses ranging from approximately I to 4 inches. The surficial organic soil depths provided in this report and on the individual "Boring Logs" are based on observations of field personnel and should be considered approximate. Please note that the transition from surficial organic soils to underlying materials may be gradual, and therefore the observation and measurement of the surficial organic soil depth is subjective. Actual surficial organic soil depths should be expected to vary and generally increases with the amount of vegetation present over the site. Surficial Organic Soil is typically a dark -colored soil material containing roots, fibrous matter, and/or other organic components, and is generally unsuitable for engineering purposes. SUNUMT has not performed any laboratory testing to determine the organic content or other horticultural properties of the observed surficial organic soils. Therefore, the phrase "surficial organic soil" is not intended to indicate suitability for landscaping and/or other purposes. 3.2.2. Existing Fill Soils Existing fill (disturbed) soils were encountered beneath the surface materials in Boring B- 2 to approximate depth of 22 feet below the existing ground surface. When sampled, the existing fill soils generally consisted of very stiff fat clays (CH), very stiff lean clays (CL), and very stiff to hard sandy silts (ML) with rock fragments and rocks. The Standard Penetration Resistances (SPT N-values) in the existing fill soils ranged from 17 to 36 blows per foot (bpf). Please note that Boring B-2 was located on an existing stockpile. We recommend 5 Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 SUMNHT Project No. 2022.62 October 18, 2019 additional testing such as, but not limited to, test pit excavations be performed in order to further evaluate these soil conditions and contents. Should unsuitable soils be encountered, these soils should be evaluated in the field by a Geotechnical Engineer -of -Record and/or his designee prior to remediation. If fill soils are encountered at other locations in the field during construction, the fill soils should be evaluated by the Geotechnical Engineer -of -Record, or his authorized representative, with respect to the criteria outlined in Section 5.0 — Construction Considerations. 3.2.3. Residual Soils Residual (undisturbed) soils were encountered below the surface materials and/or existing fill soils and extended to either the maximum termination depth or partially weathered rock (PWR). These residual soils generally consisted of very stiff fat clays (CH), very stiff to very hard lean clays (CL), and very stiff to very hard sandy silts (ML) with varying amount rock fragments. The Standard Penetration Resistances (SPT N-values) in the residual soils ranged from 16 to greater than 50 bpf. 3.2.4. Partially Weathered Rock and Au2er Refusal Partially weathered rock (PWR) conditions were encountered in all of the borings at approximate depths beginning near the existing ground surface to 22 feet below the existing ground surface. PWR is defined as soil -like material exhibiting SPT N-values in excess of 100 bpf. When sampled, the PWR generally breaks down into sandy silts with rock fragments. Augerrefusal conditions were encountered in ten (10) of theborings at approximate depths ranging from 6.1 to 28.6 feet. Auger refusal is defined as material that could not be penetrated by the drilling equipment used during our field exploration. Materials that might result in auger refusal include large boulders, rock ledges, lenses, seams or the top of parent bedrock. Core drilling techniques would be required to evaluate the character r_0 Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 SUMNHT Project No. 2022.62 October 18, 2019 and continuity of the refusal material. However, rock coring was beyond the scope of this exploration and not performed. The following table summarizes the approximate depths that PWR and auger refusal conditions were encountered in the borings performed for this exploration. Summary Table of Partially Weathered Rock and Auger Refusal Depths Boring No. PartiaUy Weathered Rock Approx. Depth, (feet)* Auger Refusal Approx. Depth, (fee0* B-1 5.5 6.1 B-2 22 28.6 B-3 3 13.6 B-4 5.5 6.2 B-5 3 6.1 B-6 1.5 to 3 and 5.5 --- B-7 Near the existing ground surface 11.1 B-8 8 --- B-9 3 6.1 B-10 Near the existing ground surface 6.1 B-11 3 6.1 B- 12 10 12.1 *Depths were measured from the ground surface existing at the time drilling was performed. Vvhen PVV`R or auger refusal conditions were not encountered in the borings. 3.2.5. Groundwater Level Measurements At the time of drilling, groundwater was not observed in the borings. After waiting more than 24 hours, water level was observed in Boring B-12 at an approximate depth of 7 feet below the existing ground surface. It should also be noted that groundwater levels tend to fluctuate with seasonal and climatic variations, as well as with some types of construction operations. Therefore, water may be encountered during construction at depths not indicated in the borings performed for this exploration. 7 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 4.0 EVALUATIONS AND RECONMENDATIONS 4.1. General Our preliminary evaluation and recommendations are based on the project information outlined previously and on the data obtained from the field and laboratory testing program. If the structural loading, geometry, or proposed building locations are changed or significantly differ from those outlined, or if conditions are encountered during construction that differ from those encountered by the borings, SUNUMT requests the opportunity to review our recommendations based on the new information and make the necessary changes. Grading plan information with proposed foundation bearing elevations was not available for our review at the time of this report. Finish grade elevations of proposed construction in conjunction with the proposed foundation bearing elevation can have a significant effect on design and construction considerations. SUMNUT should be provided the opportunity to review the project grading plans prior to their finalization with respect to the recommendations contained in this report. 4.2. Shallow Foundation Recommendations Based on the results of the soil test borings, and our assumptions regarding site grading and assumed structural building loads, the proposed structures can be adequately supported on shallow foundation systems provided site preparation and compacted fill recommendation procedures outlined in this report are implemented concerning unsuitable soils such as fat clays. An allowable net bearing pressure of up to 3,000 pounds per square foot (psf) can be used for design of the foundations bearing on approved undisturbed residual soils, or on approved structural fill compacted to at least 95 percent of its Standard Proctor maximum dry density. Please refer to section 5.0 of this report for more information. Provided the procedures and recommendations outlined in this report are implemented and using the assumed loads, we have estimated a total settlement of less than I inch for footing design pressures of 3,000 psf. 8 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 To avoid punching type bearing capacity failure, we recommend wall foundation widths of 18 inches or more. Exterior foundations and foundations in unheated areas should be designed to bear at least 12 inches below finished grade for frost protection. To reduce the effects of seasonal moisture variations in the soils, for frost protection and for bearing capacity, it is recommended that all foundations be embedded at least 12 inches below the lowest adjacent grade. All footing excavations and undercutting remediation operations should be evaluated by the Geotechnical Engineer -of -Record or his qualified representative to confirm that suitable soils are present at and below the proposed bearing elevation and that the backFill operations are completed with the recommendations of this report. This evaluation may include hand -auger and DCP testing. If evaluation with DCP testing encounters lower penetration resistances than anticipated or unsuitable materials are observed beneath the footing excavations, these bearing soils should be corrected per the Geotechnical Engineer-of-Record's recommendations. 4.3. Retaining Wall Recommendations Design Parameters for backfill properties (i.e., friction angle, earth pressure coefficients) should use the values in the table below. These parameters are based on suitable soils with a minimum moist unit weight of 120 pcf. SUNUMT should be retained to test the actual soils used for construction to verify these design assumptions. To reduce long term creep or deflections to the wall system, desirable wall backFill soils should be used. These include non -plastic, granular soils (sands and gravels). However, these soils may not be available on site. Soil Parameters for Wall Backfill Active Passive Coefficient AHowable Modulus of Earth Earth of Earth Bearing Friction Subgrade Pressure Pressure Pressure at Capacity Angle Reaction Coefficient Coefficient Rest Slide Backfill Typel (psf) (deg) (Pei) K� Kp Ko Friction Residuum 3,000 280 200 0.361 2.77 0.531 0.4 Fill 3,000 240 150 0.421 2.37 0.593 0.4 Soils classified as elastic silts (MH) and/or fat clays (CH) shall not be used for wall backfill or in 9 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 the retained zone as shown in Table 1610.1 of the 2015 IBC. If on -site soils are used as backfill within the reinforced zone, the wall designer should address the need for wall drainage and the possibility of long-term, time -dependent movement or creep in their design At the time of report preparation, we were not provided retaining wall plans or specifications. Therefore, we request the opportunity to review the wall plans and specifications once they are finalized. Also, we recommend an external stability analysis (including global stability) of the proposed wall(s) be conducted once the site layout and wall geometry is complete. 4.4. Low to Moderate Plasticity Moisture Sensitive Soils (CL) Low to moderate plasticity and moisture sensitive (lean clays) soils were encountered in Borings B-1, B-2, B-4 and B-12 at various depths. These fine-grained soils are susceptible to moisture intrusion and can become soft when exposed to weather and/or water infiltration. Consequently, some undercutting and/or reworking (drying) of the near -surface soils may be required depending upon the site management practices and weather conditions present during construction. Should these materials be left in -place, special consideration should be given to providing positive drainage away from the structure and discharging roof drains a minimum of 5 feet from the foundations to reduce infiltration of surface water to the subgrade materials Note: Since Low to Moderate Plasticity and Moisture Sensitive Soils can become remolded (i.e., softened) under the weight of repeated construction traffic and changes in moisture conditions, these soils should be evaluated and closely monitored by the Geotechnical Engineer -of -Record or his qualified representative prior to and during fill placement. Additional testing and inspections of moisture sensitive soils may be warranted such as laboratory testing, field density (compaction) testing, hand auger borings with dynamic cone penetrometer (DCP) testing and/or test pit excavations. 10 Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 4.5. High Plasticity Moisture Sensitive Soils (CH) SUMNHT Project No. 2022.62 October 18, 2019 High plasticity and moisture sensitive (fat clays) soils were encountered in Borings B-2, B-6 and B-8 at various depths. Highly plastic soils can undergo significant changes in volume (shrink/swell behavior) with changes in moisture conditions. These soils typically provide poor subgrade support for pavements and foundations. The following table summarizes the locations and approximate depths that fat clay soils were encountered in the borings performed for this exploration. Summary Table of Fat Clay Soils Depths Boring No. Fat Clay Approx. Depth, (feet)* Boring No. Fat Clay Approx. Depth (feet)* B-2 8 to 12 B-8 3 to 5.5 B-6 1.5 *Depths were measured from the ground surface existing at the time drilling was perfo The highly plastic materials encountered in the borings performed for this exploration are typically not considered suitable for building or pavement subgrade support. Depending on final subgrade elevations, we recommend the highly plastic soils be undercut from beneath foundations and pavements so that the foundation elements bear on 3 feet or more of engineered fill and pavements are supported on I 1/2feet or more of engineered fill, creating a separation between the foundation elements/pavements and the underlying highly plastic soils. The presence of the high plasticity materials can adversely affect the performance of the foundation and pavement systems. Due to the presence of highly plastic soils at the project site, we recommend the following be implemented by the design team: I The high plasticity materials should be undercut from all structural and pavement areas. The undercut subgrades should be evaluated by a staff professional upon completion of undercut operations. Once the evaluation is completed and the subgrade appears suitable, structural fill should be placed to subgrade elevation. I I Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 2. Three (3) feet of separation should be provided between the high plasticity materials and foundations and one and one-half (11/2) feet of separation on pavement areas. The separation material should consist of approved structural fill materials 3. Lime stabilization techniques could be utilized in order to lower the plasticity of the referenced soils in -place and minimize any undercut. These techniques should extend to a depth of at least 3 feet below finished floor elevation of the building and at least 1.5 feet on pavement areas. It should be noted that the success of lime stabilization techniques is highly dependent upon the means and methods utilized by the contractor. 4. If the expansive soils are not undercut from beneath the structures or adequate separation is not provided, the building foundations could be designed to either penetrate the expansive soils or should be designed to resist the differential volume and prevent structural damage. Slab -on -grades should be designed as structural slabs for the expansive soils in accordance with WRI/CRSI Design of Slab -on -Ground Foundations or PTI Design and Construction of Post -Tensioned Slabs -on -Ground. 4.6. Wet Weather Conditions Contractors should be made aware of the moisture sensitivity of the near soils and potential compaction difficulties. If construction is undertaken during wet weather conditions, the surficial soils may become saturated, soft, and unworkable. The contractor can anticipate reworking and/or recompacting soils may be needed when excessive moisture conditions occur. Additionally, subgrade stabilization techniques, such as chemical (lime or lime -fly ash) treatment, may be needed to provide a more weather -resistant working surface during construction. Therefore, we recommend that consideration be given to construction during the dryer months. Surface runoff should be drained away from excavations and not allowed to pond. Concrete for foundations should be placed as soon as practical after the excavation is made. That is, the exposed foundation soils should not be allowed to become excessively dry or wet before placement of concrete. Bearing soils exposed to moisture variations may become highly disturbed resulting in 12 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 the need for undercutting prior to placement of concrete. If excavations must remain open overnight, or if rainfall becomes imminent while the bearing soils are exposed, we recommend that a 2- to 4-inch-thick "mud -mat" of lean (2000 psi) concrete be placed on the bearing soils before work stops for the night. SUMMIT recommends that special care be given to providing adequate drainage away from the building areas to reduce infiltration of surface water to the base course and subgrade materials. If these materials are allowed to become saturated during the life of the slab section, a strength reduction of the materials may result causing a reduced life of the section. 4.7. Floor Slabs Slab -on -grade floor systems may be supported on approved residual soils, or newly compacted fill, provided the site preparation and fill placement procedures outlined in this report are implemented. Depending upon the amount of cuts and/or fills, unsuitable soils such as fat clays and areas which deflect, rut or pump excessively during proof -rolling may require remediation as described in Section 5.2. We recommend floor slabs be isolated from other structural components to allow independent movement of the slab and the building foundation elements. immediately prior to constructing a floor slab, the areas should be proof -rolled to detect any softened, loosened or disturbed areas that may have been exposed to wet weather or construction traffic. Areas that are found to be disturbed or indicate pumping action during the proof -rolling should be undercut and replaced with adequately compacted structural fill. This proof -rolling should be observed by the staff professional or a senior soils technician under his/her direction. Proof -rolling procedures are outlined in the "Site Preparation" section of this report. 4.8. Pavements Subgrade Preparation The pavement sections can be adequately supported on approved non -high plasticity residual soils, or newly compacted fill, provided the site preparation and fill placement procedures outlined in this report are implemented. Immediately prior to constructing the pavement section, we recommend that the areas be proofrolled to detect any softened, loosened or disturbed areas that 13 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 may have been exposed to wet weather or construction traffic. Areas that are found to be disturbed or indicate instability during the proofrolling should be undercut and replaced with adequately compacted structural fill or repaired as recommended by the Geotechnical Engineer. This proofrolling should be observed by the staff professional or a senior soils technician under his/her direction. Proofrolling procedures are outlined in the "Site Preparation" section of this report. Due to prevalence of near surface moderate to high plasticity elastic silts and fat clays, remediation of pavement subgrade soils may be recommended (as determined by the Geotechnical Engineer during construction) including undercutting and replacement with additional NCDOT ABC stone. Alternatively, lime stabilization of pavement subgrade may be a more economical option and SUNFMT can provide lime stabilization mix design services if requested. This may be more pronounced depending on the time of the year and seasonal conditions at the time of pavement construction. We recommend contingency for some remediation efforts for the subgrade soils be considered during the planning stage. 4.9. Cut and Fill Slopes Permanent project slopes should be designed with geometry of 3 horizontal to I vertical or flatter. The tops and bases of all slopes should be located 10 feet or more from structural limits and 5 feet or more from parking limits. Fill slopes should be properly compacted according to the recommendations provided in this report. In addition, fill slopes should be overbuilt and cut to finished grade during construction to achieve proper compaction on the slope face. All slopes should be seeded and maintained after construction and adhere to local, state and federal municipal standards, if applicable. 14 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 5.0 CONSTRUCTION CONSIDERATIONS 5.1. Abandoned Utilities/Structures SUMMIT recommends that any existing utility lines be removed from within proposed building and pavement areas. The utility backfill material should be removed and the subgrade in the excavations should be evaluated by a geotechnical professional prior to fill placement. The subgrade evaluation should consist of visual observations, probing with a steel rod and/or performing hand auger borings with Dynamic Cone Penetrometer tests to evaluate their suitability of receiving structural fill. Once the excavations are evaluated and approved, they should be backFilled with adequately compacted structural fill. Excavation backFill under proposed new foundations should consist of properly compacted structural fill, crushed stone, flowable fill or lean concrete as approved by the Geotechnical Engineer -of -Record. 5.2. Site Preparation Based on the results of our borings, and dependent on final grades, the contractor can anticipate that some undercutting and/or foundation extension through fat clays, and soils with N-values less than 7 bpf may be required prior to building construction and/or fill placement. If these soils are encountered during the grading activities, the extent of the undercut required should be determined in the field by the Geotechnical Engineer -of -Record and/or an experienced staff professional. Additional testing such as test pit excavations and/or hand auger borings may be required in order to further evaluate these soil conditions, depths and locations. Topsoil, organic laden/stained soils, construction debris and other unsuitable materials should be stripped/removed from the proposed construction limits. Stripping and clearing should extend 10 feet or more beyond the planned construction limits. Upon completion of the stripping operations, we recommend areas planned for support of foundations, floor slabs, parking areas and structural fill be proof -rolled with a loaded dump truck or similar pneumatic tired vehicle (minimum loaded weight of 20 tons) under the observations of a staff professional. After excavation of the site has been completed, the exposed subgrade in cut areas should also be proof -rolled. The proof -rolling 15 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 procedures should consist of four complete passes of the exposed areas, with two of the passes being in a direction perpendicular to the proceeding ones. Any areas which deflect, rut or pump excessively during proof -rolling or fail to "tighten up" after successive passes should be undercut to suitable soils and replaced with compacted fill. The extent of any undercut required should be determined in the field by an experienced staff professional or engineer while monitoring construction activity. After the proof -rolling operation has been completed and approved, final site grading should proceed immediately. If construction progresses during wet weather, the proof -rolling operation should be repeated after any inclement weather event with at least one pass in each direction immediately prior to placing fill material or aggregate base course stone. If unstable conditions are experienced during this operation, then undercutting or reworking of the unstable soils may be required. 5.3. Difficult Excavation Based on the results of our soil test borings and dependent on final grades, it appears that the majority of general excavation for footings and shallow utilities will be possible with conventional excavating techniques. We anticipate that the residual soils can be excavated using pans, scrapers, backhoes, and front end loaders. Dependent on final grades and locations, the contractor should anticipate the excavations of PWR and auger refusal conditions will require specialized equipment and procedures. Partially weathered rock (PWR) conditions were encountered in all of the borings and auger refusal conditions were encountered in ten (10) of the borings performed for this exploration. The depth and thickness of partially weathered rock, boulders, and rock lenses or seams can vary dramatically in short distances and between the boring locations; therefore, soft/hard weathered rock, boulders or bedrock may be encountered during construction at locations or depths, between the boring locations, not encountered during this exploration. The table below may be used as a quick reference for rippability of in -place materials. 16 Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 SUMNHT Project No. 2022.62 October 18, 2019 Summary of Rippability Based on SPT N-Values N-Values as Shown Description of N-Values Anticipated Rippability on Boring Logs These materials may generally be excavated 60 < N-Value N-values less than 60 bpf with heavy-duty equipment such as a Caterpillar D-8 with a single -shank ripper N-values more than 60 bpf, These materials are considered marginally 60 < N-Value < 50/3" but less than 50 blows per 3 excavatable, even with heavy-duty inches of penetration equipment. N-values more than 50 blows Blasting and/or removal with impact 50/3" < N-Value per 3 inches of penetration hammers is typically required to excavate these materials. *This table is for general information only. Actual rippability is dependent upon many other factors as stated above. I Care should be exercised during excavations for footings on rock to reduce disturbance to the foundation elevation. The bottom of each footing should be approximately level. When blasting is utilized for foundation excavation in rock, charges should be held above design grades. Actual grades for setting charges should be selected by the contractor and he should be responsible for any damage caused by the blasting. All loose rock should be carefully cleaned from the bottom of the excavation prior to pouring concrete. Footing excavations in which the rock subgrade has been loosened due to blasting should be deepened to an acceptable bearing elevation. in our professional opinion, a clear and appropriate definition of rock should be included in the project specifications to reduce the potential for misunderstandings. A sample definition of rock for excavation specifications is provided below: Rock is defined as any material that cannot be dislodged by a Caterpillar D-8 tractor, or equivalent, equipped with a hydraulically operatedpower ripper (or by a Cat 325 hydraulic backhoe, or equivalent) without the use ofdrilling and blasting. Boulders or masses of rock exceeding Y2 cubic yard in volume shall also be considered rock excavation. This classification does not include materials such as loose rock, concrete, or other materials that can be removed by means other than drilling and blasting, but which for any reason, such as economic reasons, the Contractor chooses to remove by drilling and blasting. 17 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 5.4. Temporary Excavation Stability Localized areas of soft or unsuitable soils not detected by our borings, or in unexplored areas, may be encountered once grading operations begin. Vertical cuts in these soils may be unstable and may present a significant hazard because they can fail without warning. Tberefore, temporary construction slopes greater than 5 feet in height should not be steeper than two horizontal to one vertical (2H: IV), and excavated material should not be placed within 10 feet of the crest of any excavated slope. In addition, runoff water should be diverted away from the crest of the excavated slopes to prevent erosion and sloughing. Should excavations extend below final grades, shoring and bracing or flattening (laying back) of the slopes may be required to obtain a safe working environment. Excavation should be sloped or shored in accordance with local, state and federal regulations, including OSHA (29 CFR Part 1926) excavation trench safety standards. 5.5. Structural Fill Soil to be used as structural fill should be free of organic matter, roots or other deleterious materials. Structural fill should have a plasticity index (PI) less than 25 and a liquid limit (LL) less than 50 or as approved by the Geotechnical Engineer -of -Record. Compacted structural fill should consist of materials classified as either CL, ML, SC, SM, SP, SW, GC, GM, GP, or GW per ASTM D-2487 or as approved by the Geotechnical Engineer -of -Record. Off -site borrow soil should also meet these same classification requirements. Non -organic, low -plasticity on -site soils are expected to meet this criterion. However, successful reuse of the excavated, on -site soils as compacted structural fill will depend on the moisture content of the soils encountered during excavation. We anticipate that scarifying and drying of portions of the on -site soils will be required before the recommended compaction can be achieved. Drying of these soils will likely result in some delay. All structural fill soils should be placed within the proposed structural pad and extending at least 5 feet beyond the perimeter of the pad and foundation limits. All structural fill soils should be 18 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 placed in thin (not greater than 8 inches) loose lifts and compacted to a minimum of 95 percent of the soil's Standard Proctor maximum dry density (ASTM D 698) at/or near optimum moisture content (±2%). The upper 2 feet of structural fill should be compacted to a minimum of 100 percent of the soil's Standard Proctor maximum dry density (ASTM D 698) at/or near optimum moisture content (±2%). Some manipulation of the moisture content (such as wetting, drying) may be required during the filling operation to obtain the required degree of compaction. The manipulation of the moisture content is highly dependent on weather conditions and site drainage conditions. Therefore, the grading contractor should be prepared to both dry and wet the fill materials to obtain the specified compaction during grading. Sufficient density tests should be performed to confirm the required compaction of the fill material. 5.6. Suitability of Excavated Soils for Re -Use Except for the fat clay soils encountered during this exploration, the soils encountered in the borings should be suitable to be used as structural fill material provided the recommendations in this report are implemented. These soils may be utilized as non-structural fill and backfill at landscaped or non -pavement areas of the project. We recommend non-structural fill to be compacted to at least 92 percent of the soil's Standard Proctor Maximum Dry Density to reduce settlement of the fill soils particularly over utility trenches. However, if approved by the Geotechnical Engineer -of -Record, high plasticity soils encountered during general site grading can be mixed/blended and/or mixed with lower plasticity soils and used as structural fill. We recommend that mixed soils be used below the top five (5) feet at deeper fill locations and adequate drainage be provided away from structural and pavement areas. The top five (5) feet should consist of materials classified as either CL, ML, SC, SM, SP, SW, GC, GM, GP or GW per ASTM D-2487 or as approved by the Geotechnical Engineer -of -Record. All fill soils should be placed in thin (not greater than 8 inches) loose lifts and compacted to a minimum of 95 percent of the soil's Standard Proctor maximum dry density (ASTM D 698) at near optimum moisture content (±2%). 19 Report of Geotechnical Subsurface Exploration SUMNHT Project No. 2022.62 Glencroft - Phase 2 October 18, 2019 5.7. Engineering Services During Construction As stated previously, the engineering recommendations provided in this report are based on the project information outlined above and the data obtained from field and laboratory tests. However, unlike other engineering materials like steel and concrete, the extent and properties of geologic materials (soil) vary significantly. Regardless of the thoroughness of a geotechnical engineering exploration, there is always a possibility that conditions between borings will be different from those at the boring locations, that conditions are not as anticipated by the designers, or that the construction process has altered the subsurface conditions. This report does not reflect variations that may occur between the boring locations. Therefore, conditions on the site may vary between the discrete locations observed at the time of our subsurface exploration. The nature and extent of variations between the borings may not become evident until construction is underway. To account for this variability, professional observation, testing and monitoring of subsurface conditions during construction should be provided as an extension of our engineering services. These services will help in evaluating the Contractor's conformance with the plans and specifications. Because of our unique position to understand the intent of the geotechnical engineering recommendations, retaining us for these services will also allow us to provide consistent service through the project construction. Geotechnical engineering construction observations should be performed under the supervision of the Geotechnical Engineer -of -Record from our office who is familiar with the intent of the recommendations presented herein. This observation is recommended to evaluate whether the conditions anticipated in the design actually exist or whether the recommendations presented herein should be modified where necessary. Observation and testing of compacted structural fill and backfill should also be provided by our firm. 20 Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 SUMNHT Project No. 2022.62 October 18, 2019 6.0 RELIANCE AND QUALIFICATIONS OF REPORT This geotechnical subsurface exploration has been provided for the sole use of True Homes. This geotechnical subsurface exploration should not be relied upon by other parties without the express written consent of SUMMIT and True Homes. The analyses and recommendations submitted in this report were based, in part, on data obtained from this exploration. If the above -described project conditions are incorrect or changed after the issuing of this report, or subsurface conditions encountered during construction are different from those reported, SUMMIT should be notified and these recommendations should be re-evaluated based on the changed conditions to make appropriate revisions. We have prepared this report according to generally accepted geotechnical engineering practices. No warranty, express or implied, is made as to the professional advice included in this report. 21 Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 C'C"L'EJ9RATfNG 15 YEARS SUMNHT Project No. 2022.62 October 18, 2019 UMMIT ENGINEERING, LABORATORY & TESTING, P.C. APPENDIX I — Figures nrty I :)od Ilion Homes �9. � Toll road) F1 751] Styx Cuthbertson Trucking .A I A 9.6 vsl� SITE 6;� Fl-7511 1w F1 7 54] F1 7-5 3� —7 qA 04, 1%, O� F17541 I Figure I Glencroft Site Vicinity Map Phase 2 CE'-EBRATiNG 15 YEPIR5 Ansonville Road Wingate, North Carolina SUMMIT ENGINEERING, �ORATORY & TESTING, P.C. 3575 Centre Circle Fort Mill, South Carolina 29715 �SCALE:NTS SUMMIT Project No.: 2022.62 (803) 504-1717 @ top -J _+ JL J L B-5 PWR-31 ?B-6 I ILI VOL C H - 1. 5' @ @ PWR-1.5'to Yand 5.5' VC L -J L Al 0 1@ 4 L L @ 'O'B-7 1411-Near the Existing FF IB-4 \e Ground Surface L-L�JAR-6. L r @ L 0" L F B - 12 _J L L PWR-10":'5 + B-3' PWR-YJ + MMI B-8 -!=-zx + @ + + L L �-W�. CH-3' to 5.5' — _J L @ r + L J L PWR 8' 77 B-1 I 0 1 "* J-0 L L X� B B-2 0 Y, -9 PWR-2�' NkR-28.6 --- Boring locations were not .)B-1 PWR-5.51 surveyed and should be T 7. � V\ '3 r considered approximate , .1 E) A� Cirl- pprox. rat ClaySoilliep PWR - Approx. Partially Weathered Rock Depth B-10 C Al V.: Figure 2 Glencroft Boring Location Plan Phase 2 Approx. Soil Test Boring Ansonville Road Location Wingate, North Carolina SCALE:NTS I SUMMIT Project No.: 2022.62 PWR-Near the Existing Ground Surface 4r'O'W-// W-!t C�'-EBPATING 15 YEAP-S / AMMON* SUMMIT ENGINMEMNG, L�O�TORY & �SnNG, P.C. 3575 Centre Circle Fort Mill, South Carolina 29715 (803 ) 504-17 , 7 Report of Geotechnical Subsurface Exploration Glencroft - Phase 2 C'C"L'EJ9RATfNG 15 YEARS SUMNHT Project No. 2022.62 October 18, 2019 UMMIT ENGINEERING, LABORATORY & TESTING, P.C. APPENDIX 2 — Boring Logs SUMMIT Engineering, Laboratory & Testing, P.C. KEY TO SYMBOLS 3575 Centre Circle Fort Mill, South Carolina 29715 SUMMIT 704.504.1717 �­ ........ ...... summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wingate, Union County, North Carolina LITHOLOGIC SYMBOLS SAMPLER SYMBOLS (Unified Soil Classification System) Standard Penetration Test F-1 BLANK CH: USCS High Plasticity Clay CL: USCS Low Plasticity Clay FILL: Fill (made ground) IVILS: USCS Sandy Silt TOPSOIL: Topsoil PWR: Partially Weathered Rock WELL CONSTRUCTION SYMBOLS ABBREVIATIONS LL -LIQUID LIMIT (%) TV -TORVANE PI -PLASTIC INDEX(%) PID -PHOTOIONIZATION DETECTOR W - MOISTURE CONTENT (%) LIC -UNCONFINED COMPRESSION DID - DRY DENSITY (PCF) ppm -PARTS PER MILLION NP -NON PLASTIC Water Level at Time -200 - PERCENT PASSING NO. 200 SIEVE Drilling, or as Shown PP - POCKET PENETROMETER (TSF) Water Level at End of Drilling, or as Shown Water Level After 24 Hours, or as Shown SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-01 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/7/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 4.8'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- Lu A SPT N VALUE A z 0 U) 0 20 40 60 80 100 = Q-0 MATERIAL DESCRIPTION Lu Lu ED uj > 3: �- 0 z -i P . L MC LL 0 -A W < LL D 0 JD< Fn 0 > 0 20 40 60 80 100 -i (D �z 0 0 z Lu < Lu El FINES CONTENT (%) El U) 0 2 0 4 0 6 0 8 0 100 Approx. 3" of Topsoil (CL) RESIDUUM: Very Stiff Light Brown, Yellow and Gray Sandy Lean CLAY SPT ........... ........ ........ ........ 7-7-11 1 (18) (ML) Very Hard Light Brown and Yellow Sandy SILT with Rock Fragments 18-31-35 ........ .. .... ...... ....... (66) 5.0 4.8ft (ML) Pa rtially Weathered Rock (PWR) when sampled becomes Light Brown, Yellow and Gray Sandy SILT with Rock SPT ................. ........ ........ 50 Fragments 3 (50/1.25") Bottom of Boring at 6.1 feet bgs, Auger Refusal 10.0 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-02 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/7/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 20.2'bq LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- z W -i Lu 0 = Q-0 < LL (D MATERIAL DESCRIPTION Lu Lu Lu ED D �z < U) uj > 0 0 Lu U) 3: �- 0 z -i JD< Fn 0 > 0 z A SPT N VALUE A 0 20 40 60 80 100 P . L MC LL 0 -A 0 20 40 60 80 100 El FINES CONTENT (%) El 0 20 40 60 80 100 Approx. 1 of Topsoil (ML) FILL: Hard Light Brown, Yellow and Gray Sandy SILT with Rock Fragments ........ ........ ........ ........ J�S tPT 1 1 : 11-16-20 (36) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (ML) FILL: Tj SPT 13-12-18 Very Stiff Light Brown, Yellow and Gray Sandy SILT with Rock ........ ...... ....... 5.0 Fragments - - - - - - - - - - - - - - - - - - - - - - - - - - A 2 (30) Tj SPT 18-16-17 Hard Light Brown, Yellow and Gray Sandy SILT with Rock Fragments A 3 (33) ........ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (CH) FILL: .......... ...... ........ ........ ........ SPT 8-6-11 Very Stiff Light Brown and Brownish Gray Sandy Fat CLAY with .. ........ - ............. ........ ........ 10.0 Rock Fragments (NTLFFFLC - - - - - - - - - - - - - - - - - - - - - - - - - 4 (17) ........ Hard Light Brown, Red and Gray Slightly Clayey Sandy SILT with Rock Fragments Tj SPT 11-17-15 ........ ...... 15.0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (CL) FILL: (32) ................. ........ ........... Very Stiff Moist Light Brown, Red and Gray Sandy Lean CLAY ........ .. .... ...... ........ . ..... with Rock Fragments Tj SPT 6-10-7 ....... ........ ........ ........ ........ 20.0 20.2ft —6 (17) ..... .... ........... ........ ........ ....... (ML) RESIDUUM: Partially Weathered Rock (PWR) when sampled becomes Light Brown and Yellow Sandy SILT with Rock Fragments >> SPT 50 7 (50/3") 25.0 Bottom of Boring at 28.6 feet bgs, Auger Refusal 50 L8 (50/0.5") 1 30,0 SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-03 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/7/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 9.5'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- Lu A SPT N VALUE A z 0 U) 0 20 40 60 80 100 = Q-0 MATERIAL DESCRIPTION Lu Lu ED uj > 3: �- 0 z -i P . L MC LL 0 -A W < LL D 0 JD< Fn 0 > 0 20 40 60 80 100 -i (D �z 0 0 z Lu < Lu El FINES CONTENT (%) El U) 0 20 40 60 80 100 Approx. 3" of Topsoil (ML) RESIDUUM: Very Hard Yellowish Brown, Gray and White Sandy SILT with Rock Fragments FSP1T 13-19-39 .. .... ...... ....... (58) (ML) Pa rtially Weathered Rock (PWR) when sampled becomes Light Brown, Gray and White Sandy SILT with Rock Fragments SPT 46-50 &L_2 >> (50/4 5.0 50 >>A 3 (50/4") 50 >>A 4 (50/3.5 9.5ft 10.0 Bottom of Boring at 13.6 feet bgs, Auger Refusal 5 5/0 01 (5 .5") 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-04 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/7/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 4.8'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- Lu A SPT N VALUE A z 0 U) 0 20 40 60 80 100 = Q-0 MATERIAL DESCRIPTION Lu Lu ED uj > 3: �- 0 z -i P . L MC LL 0 -A W < LL D 0 JD< Fn 0 > 0 20 40 60 80 100 El FINES CONTENT (%) El -i Lu (D �z < 0 Lu 0 z U) 0 2 0 4 0 6 0 8 0 100 Approx. 3" of Topsoil (CL) RESIDUUM: Very Hard Light Brown, Yellow and Gray Sandy Lean CLAY with Rock Fragments SPT 13-26-41 PT 1 (67) (ML) Hard Light Brown, White and Gray Slightly Clayey Sandy SILT with Rock Fragments 14-15-23 ........ .. .... ....... (38) 5.0 4.8ft (ML) Pa rtially Weathered Rock (PWR) when sampled becomes Light Brown and Gray Sandy SILT with Rock Fragments SPT 50 Bottom of Boring at 6.2 feet bgs, Auger Refusal 3 10.0 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. 3575 Centre Circle 11AM1k BORING NUMBER B-05 Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/7/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 4.2'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- z W -i Lu 0 = Q-0 < LL (D MATERIAL DESCRIPTION Lu Lu Lu ED D �z < U) uj > 0 0 Lu U) 3: �- 0 z -i JD< Fn 0 > 0 z A SPT N VALUE A 0 20 40 60 80 100 P . L MC LL 0 -A 0 20 40 60 80 100 El FINES CONTENT (%) El 0 20 40 60 80 100 Approx. 3" of Topsoil (ML) RESIDUUM: Very Hard Light Brown, Yellow and Gray Slightly Clayey Sandy SILT with Rock Fragments FSP1T 10-14-50 .. .... ...... (64) (ML) Pa rtially Weathered Rock (PWR) when sampled becomes Light Brown and Gray Sandy SILT with Rock Fragments 4.2ft SPT 2 48-50 (50/4 5.0 ........................................ Bottom of Boring at 6.1 feet bgs, Auger Refusal 51 1 3 (5 O�D/uo. 5 10.0 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-06 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/8/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 9.8'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- Lu A SPT N VALUE A z 0 U) 0 20 40 60 80 100 = Q-0 MATERIAL DESCRIPTION Lu Lu ED uj > 3: �- 0 z -i P . L MC LL 0 -A W < LL D 0 JD< Fn 0 > 0 20 40 60 80 100 El FINES CONTENT (%) El -i Lu (D �z < 0 Lu 0 z U) 0 20 40 60 80 100 Approx. 3" of Topsoil (CH) RESIDUUM: Light Brown and Gray Fat CLAY ........ ........ ....... (ML) RESIDUUM: Partially Weathered Rock (PWR) when sampled becomes Light 8-40-50 >> Brown, Yellow and White Slightly Clayey Sandy SILT with Rock (50/5") Fragments ......... (ML) Very Hard Light Brown, Yellow and White Slightly Clayey Sandy SILT with Rock Fragments 25-29-40 (69) 5.0 4 AP (ML) Partially Weathered Rock (PWR) when sampled becomes Light Brown and Yellow Sandy SILT with Rock Fragments T SPT P: 41-48-50 1!3 >>A (50/2") 41-50 4 (50/2.75") ........ >>A 10.0 9.8ft ........ ........ ........ ........ PT SPT�� Bottom of Boring at 13.7 feet bgs, Boring Terminated �5025.��� 50/2 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-07 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/8/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 8.3'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- Lu A SPT N VALUE A z 0 U) 0 20 40 60 80 100 = Q-0 MATERIAL DESCRIPTION Lu Lu ED uj > 3: �- 0 z -i P . L MC LL 0 -A W < LL D 0 JD< Fn 0 > 0 20 40 60 80 100 -i (D �z 0 0 z Lu < Lu El FINES CONTENT (%) El U) 0 2 0 4 0 6 0 8 0 100 Approx. 4" of Topsoil (ML) RESIDUUM: Partially Weathered Rock (PWR) when sampled becomes Light Brown, Yellow and Gray Sandy SILT with Rock Fragments SPT 50 1 (50/2.25") ........ ................. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (ML) Partially Weathered Rock (PWR) when sampled becomes ........... - .... .......................... Light Brown and Gray Sandy SILT with Rock Fragments SPT 50 2 5.0 T SPT 50 >>A 3 (50/5.25") 8.3ft 50 4 (50/2.5") ...... 10.0 Bottom of Boring at 11.1 feet bgs, Auger Refusal 1� �5O 050 75-���� 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. 3575 Centre Circle 11AM1k BORING NUMBER B-08 Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/8/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 10.5'bq LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- z W -i Lu 0 = Q-0 < LL (D MATERIAL DESCRIPTION Lu Lu Lu ED D �z < U) uj > 0 0 Lu U) 3: �- 0 z -i JD< Fn 0 > 0 z A SPT N VALUE A 0 20 40 60 80 100 P . L MC LL 0 -A 0 20 40 60 80 100 El FINES CONTENT (%) El 0 20 40 60 80 100 Approx. 3" of Topsoil (ML) RESIDUUM: Very Stiff Yellowish Brown and Gray Sandy SILT SPT 5-8-11 ........... ........ ........ ........ 1 (19) (CH) Very Stiff Yellowish Brown, Red and Gray Sandy Fat CLAY 6-6-10 ........ .. .... ...... ....... (16) 5.0 (ML) Very Hard Light Brown, Yellow and Gray Slightly Clayey Sandy SILT ................. ....... ........ ........ 28-32-44 (76) ........ ........ ........ ....... (ML) Pa rtially Weathered Rock (PWR) when sampled becomes Reddish Brown, Black and Gray Slightly Clayey Sandy SILT with Rock Fragments 32-50 (50/5.75 '.) 10.0 10.5ft ------------------------------ (ML) Partially Weathered Rock (PWR) when sampled becomes Light Brown and Gray Slightly Clayey Sandy SILT with Rock Fragments and Clay Seams ........ ................. >>A SPT 5 42-47-50 (50/3.5") 15.0 Bottom of Boring at 14.8 feet bgs, Boring Terminated 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-09 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/8/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 4.6'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- Lu A SPT N VALUE A z 0 U) 0 20 40 60 80 100 = Q-0 MATERIAL DESCRIPTION Lu Lu ED uj > 3: �- 0 z -i P . L MC LL 0 -A W < LL D 0 JD< Fn 0 > 0 20 40 60 80 100 -i (D �z 0 0 z Lu < Lu El FINES CONTENT (%) El U) 0 2 0 4 0 6 0 8 0 100 Approx. 4" ofTopsoil (ML) RESIDUUM: Very Hard Light Brown, Yellow and Gray Slightly Clayey Sandy T. . SILT with Rock Fragments FS P1T 11-26-35 .. .... ...... ....... (61) (ML) Partially Weathered Rock (PWR) when sampled becomes Light Brown and Gray Slightly Clayey Sandy SILT with Rock 50 Fragments 2 (50/3 5.0 Bottom of Boring at 6.1 feet bgs, Auger Refusal 4.6ft Im .................. ........ 50 3 (5 0/1--) 10.0 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. 3575 Centre Circle 11AM1k BORING NUMBER B-10 Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/8/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 4.1'bgs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- z W -i Lu 0 = Q-0 < LL (D MATERIAL DESCRIPTION Lu Lu Lu ED D �z < U) uj > 0 0 Lu U) 3: �- 0 z -i JD< Fn 0 > 0 z A SPT N VALUE A 0 20 40 60 80 100 P . L MC LL 0 -A 0 20 40 60 80 100 El FINES CONTENT (%) El 0 2 0 4 0 6 0 8 0 100 Approx. 3" ofTopsoil (ML) RESIDUUM: Partially Weathered Rock (PWR) when sampled becomes Light Brown and Gray Sandy SILT with Rock Fragments 1 50 (50/4.5") 50 4.1ft 2 (50/3.25 5.0 ............................... Bottom of Boring at 6.1 feet bgs, Auger Refusal 3 (50/0.5") 10.0 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-1 1 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/7/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_ 4.5'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- Lu A SPT N VALUE A z 0 U) 0 20 40 60 80 100 = Q-0 MATERIAL DESCRIPTION Lu Lu ED uj > 3: �- 0 z -i P . L MC LL 0 -A W < LL D 0 JD< Fn 0 > 0 20 40 60 80 100 -i (D �z 0 0 z Lu < Lu El FINES CONTENT (%) El U) 0 2 0 4 0 6 0 8 0 100 Approx. 4" ofTopsoil (ML) RESIDUUM: Hard Light Brown, Yellow and Gray Slightly Clayey Sandy SILT T. . with Rock Fragments SP1T 9-11-20 (31) (ML) Partially Weathered Rock (PWR) when sampled becomes Light Brown and Gray Sandy SILT with Rock Fragments SPT 50 2 (50/5.25" 4.5ft 5.0 Bottom of Boring at 6.1 feet bgs, Auger Refusal SPT 50 3 10.0 15.0 20.0 SUMMIT Engineering, Laboratory & Testing, P.C. BORING NUMBER B-12 3575 Centre Circle 11AM1k Fort Mill, South Carolina 29715 PAGE I OF I SUMMIT 704.504.1717 summit-companies.com CLIENT True Homes PROJECT NAME Glencroft Phase 2 PROJECT NUMBER 2022.62 PROJECT LOCATION Wing te, Union County, North Carolina DATE STARTED 10/8/19 COMPLETED GROUND ELEVATION HOLE SIZE 6 inches DRILLING CONTRACTOR FST GROUND WATERICAVE-IN: DRILLING METHOD Hollow Stem Auger AT TIME OF DRILLING --- GW NE ATID / Caved in Depth (a)_'bqs LOGGED BY FST CHECKED BY A. Jordan AT END OF DRI LLI NG --- GW > 24 Hrs at 7 feet bgs NOTES Refer to Figure 2 "Boring Location Plan" for Approx. Boring Location AFTER DRILLING --- Lu A SPT N VALUE A z 0 U) 0 20 40 60 80 100 = Q-0 MATERIAL DESCRIPTION Lu UJ ED uj > 3: �- 0 z -i D < PL MC LL 1 -11 W < LL 0 j Fn 0 > 0 20 40 60 80 100 -i (D �z 0 0 z Lu < Lu El FINES CONTENT (%) El U) 0 2 0 4 0 6 0 8 0 100 Approx. 3" of Topsoil (CL) RESIDUUM: SPT 6-10-12-10 Very Stiff Pale Brown, Light Gray and Brownish Yellow Sandy 1 (22) Lean CLAY - - - - - - - - - - - - - - - (CL) Hard Pale Brown, Light Gray jy- and Brownish Yellow San ........ .... ........ Lean CLAY SPT 34-17-20-20 2 (37) - - - - - - - - - - - - - - - - - - - - - - - - - - - - (CL) Very Stiff Pale Brown, Light Gray and Yellowish Red Sandy - - ........ 5.0 Lean LAY SPT 3 6-10-16-18 (26) - - - - - - - - - - - - - - - - - - - - - - - - - - - - (CL) Hard Pale Brown, Light Gray and Yellowish Red Sandy Lean - - ........ ... .... ........ ........ ........ CLAY SPT 8-11-20-23 4 (31) - - - - - - - - - - - - - - - - - - - - - - - - (CLFV;ry Hard Pale Brown, Light Gray and Yellowish Red Sand y - - ........ ........ Lean CLAY SPT 20-30-33-50/3" 5 (63) 10.0 artially Weathered Rock (PWR) when sampled becomes 50 Pale Brown Sandy SILT with Rock Fragments 6 L (50/1.75") Bottom of Boring at 12.1 feet bgs, Auger Refusal SPT' 50 7 15.0 20.0