Geotechnical Report - Amend 0005.pdf

February 10, 2023 Revised June 15,, 2023

Bamforth Engineers + Surveyors, Inc.

2207 Hampton Boulevard Norfolk, Virginia 23517

Attention: Ms. Anna Lee Bamforth, PE, LS

Subject: Report of Geotechnical Services P-1574 1sr MRSB Operational Support Facility MCB Camp Lejeune, Stone Bay, North Carolina GER Project No. 110-8072

GeoEnvironmental Resources, Inc. is pleased to present this report of geotechnical exploration for the above referenced project. Our services were performed in accordance with our proposal P22-110-7659 dated 21 June 2022.

We appreciate the opportunity to serve as your geotechnical consultant on this project and trust that you will contact us at your convenience with any questions concerning this report or the project in general.

Sincerely, GeoEnvironmental Resources, Inc.

J. Andrew Blythe, E.I.T. Crystal Cox, P.E.

Geotechnical Engineer Senior Engineer

Scott A. Barnhill, P.E.

Executive Vice President

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C O

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ONWEALTH OF VIRGIN

IA

PROFESSIONAL ENGIN

EER

SCOTT A. BARNHILL

Lic. No. 012520

EXECUTIVE SUMMARY

GER

Subsurface conditions for the 1st MRSB Operational Support Facility were explored by two Standard Penetration Test (SPT) soil borings to a depth of about 12 feet below the existing ground surface, one SPT soil boring to a depth of about 75 feet below the existing ground surface, and one seismic cone penetration test (SCPTu) sounding to a depth of about 77 feet below the existing ground surface. Pore pressure dissipation tests were conducted at the SCPTu testing location. One constant head permeameter test was conducted at a proposed stormwater management location at a depth of about 2 feet below the existing ground surface. Geotechnical laboratory analysis of samples included tests for natural moisture content, sieve analysis, plasticity, moisture-density relationship, CBR, and consolidation. Chemical laboratory analysis of two composite soil samples included tests for TPH-DRO, TPH- GRO, TCLP (VOCs, SVOCs, PCBs, pesticides, herbicides, and metals), PFAS, ignitibility, water content, pH, sulfides, chlorides, soluble sulfates, oxidation-reduction potential, and electrical resistivity.

The general soil profile interpreted from the soil borings is composed of 1 man-made layer along with 3 native stratigraphic layers. These layers include:

Stratum A – Uncontrolled FILL material sampled as silty Sand to a depth of about 4 feet below the ground surface.

Stratum 1 – Very loose to loose, clayey SAND and silty SAND, to a depth of about 12 to 17 feet below the ground surface.

Stratum 2 – Very soft, lean CLAY with silt, fat CLAY with silt, and very silty CLAY to a depth of about 42 feet below the ground surface.

Stratum 3 – Loose to dense, clayey SAND, silty SAND, silty GRAVEL with sand, well-graded SAND, and poorly-graded SAND with silt, to the termination depth of exploration of about 75 feet below the ground surface.

A design CBR value of 2 is appropriate for the project. Preliminary pavement sections are provided within.

The building can likely be supported using shallow foundations for provided structural loads. The allowable soil bearing pressure is 2000 psf.

Conventional ground supported concrete floor slabs can be used for the project. A turned down slab is also an option.

Estimated total settlements of properly supported footings are expected to be tolerable for provided structural loads and fill depths.

Measured infiltration rates of upper layer silty sands are provided.

Most of the upper soils excavated from the site are not expected to be suitable for reuse as structural fill and backfill on the project based on field and laboratory tests. It should also be noted that due to minor contaminant detection in selected soil samples, construction activities at the site may require specialized soil disposal.

Seismic Site Class D is expected to be appropriate for the project site based on this exploration and our past experience.

PAGE

PURPOSE OF EXPLORATION 1

PROJECT INFORMATION 1

SITE DESCRIPTION 1

SITE GEOLOGY 1

EXPLORATION PROGRAM 1

EXPLORATION RESULTS 2

Soil Stratigraphy 2

Soil Survey 3 Groundwater 3 Surface Materials 3

Infiltration Testing 3 Photoionization Detection Screening 3 Geotechnical Laboratory Testing 3 Chemical Laboratory Testing 3

SUBSURFACE EVALUATION 4

RECOMMENDATIONS 4

Shallow Foundations 5 Ground Slabs 5 Pavement 6 Earthwork 7 Fill and Backfill 7 Underground Utilities 8 Stormwater Management BMPs 8 Seismic Properties 8

LIMITATIONS 8

APPENDICES

APPENDIX A - Drawings

APPENDIX B - Field Test Data APPENDIX C - Laboratory Test Data APPENDIX D – Procedures

APPENDIX E – Calculations

P-1574 1st MRSB Operational Support Facility June 15, 2023 GER Project 110-8072 Page 1

Purpose of Exploration The purpose of this study was to collect geotechnical data for the planned Marine Raider Support Battalion (MRSB) Operational Support Facilities at the project site and to develop conceptual building foundation and site development design in support of the execution of this Design-Bid-Build (DBB) project.

Project Information The project includes the construction of a single-story 9,604 square foot (SF) SOF Marine Raider Support Battalion Operational Support Facilities and miscellaneous supporting structures, utilities, parking, roadways, and site work. An additional parking lot expansion will be located north of the proposed facility at an existing parking area. The building facilities will utilize structural steel framing with brick veneer. The proposed supporting facilities will include paving, sidewalks, storm water management, clearing and grubbing, earthwork, fill, grading, landscaping, and underground utilities.

The project will include the removal of vegetation and utilities within the proposed site footprint to accommodate the new facilities.

In regards to structural loads: column loading is not anticipated to exceed 35 kips, wall loading is not anticipated to exceed 1 klf, and floor loading is not anticipated to exceed 150 psf.

Fill used to increase existing grades at the site is not anticipated to exceed 2 ft.

Site Description The project site is located at the Marine Corps Base Camp Lejeune (MCBCL) in Jacksonville, North Carolina within the Expeditionary Operations Training Group (EOTG) area at Stone Bay. Specifically, the building site is located west of building RR527 within a cleared space;

and the proposed parking lot site is located within the existing wooded area west of the existing parking lot onthe west side of Loop Road. The approximate project limits are shown on Drawing 1 in Appendix A.

Site Geology The project site lies within North Carolina’s Atlantic Coastal Plain physiographic province. The Coastal Plain is characterized by an eastward thickening wedge of marine, estuarine and fluvial sediments that were deposited in a series of marine transgressive-regressive cycles, or high and low stands of sea level, during the Holocene to Miocene epochs of the late Cenozoic era.

According to the 1985 Geologic Map of North Carolina, the upper geologic units at the site are composed of unconsolidated Holocene and Upper Pleistocene age deposits of undivided members. Older underlying units include consolidated Tertiary deposits of the River Bend Formation, undivided, described as limestone, calcarenite overlain by and intercalated with indurated sandy, molluscan-mold limestone.

Historical Review

Based on historical satellite imagery provided in Appendix A, the site was wooded for many years.

Clearing was performed in the southern area of the site between 2006 and 2008. Development of several buildings on the site occurred between 2014 to 2015.

FILL material is likely in the building site area as a remnant of former development and demolition activity.

Exploration Program The subsurface exploration program consisted of the following sampling and testing at the approximate locations shown on Drawing 2 in Appendix A:

Performing 2 Standard Penetration Test (SPT) soil borings to a depth of 12 feet below the existing ground surface and 1 SPT soil boring to a depth of 75 feet below the existing ground surface.

Collecting 2 hand dug bulk samples for CBR testing.

Collecting 2 composite soil samples from the upper 1 to 4 feet for laboratory chemical analysis.

Performing 1 Seismic Cone Penetration Test (SCPTu) sounding to a depth of 77 feet below the existing ground surface at which it terminated due to refusal.

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Performing pore pressure dissipation in representative soft clay/silt strata for estimation of the horizontal conductivity ch.

Performing 1 field constant head borehole permeability test.

Performing geotechnical laboratory testing that included natural moisture content, sieve analysis, plasticity, moisture-density relationship, CBR, and consolidation tests on selected representative samples recovered from the soil borings.

Performing chemical laboratory testing that included TCLP (VOCs, SVOCs, pesticides, herbicides, PCBs, and metals), TPH-DRO & GRO, PFAS, ignitability, corrosivity, reactivity, water content, pH, soluble sulfates, chlorides, electrical resistivity, redox potential, and sulfides on two composite soil samples.

The soil borings were performed on December 15 and 16, 2022. SPT borings were advanced by a CME 45 ATV mounted drill rig using boreholes drilled by mud rotary techniques. Standard penetration test sampling was conducted in these borings at discreet intervals in general accordance with ASTM D1586. An automatic hammer was used to drive the sampler. Small, disturbed samples obtained during the test were visually classified in general accordance with ASTM D2487 and selected representative samples were saved for laboratory testing.

Observation of water table depth was made in the open boreholes during and immediately following completion of drilling. All boreholes were backfilled with a bentonite grout mix upon completion of the testing, groundwater sampling, and water level measurements.

The SCPTu soundings were conducted on December 21, 2022. The cone penetrometer test (CPT) sounding was conducted using an integrated electronic seismic piezocone with a 15 cm2 tip and a 225 cm2 friction sleeve. The cone is designed with an equal end area friction sleeve and a tip end area ratio of 0.80. The piezocone dimensions and the operating procedure were in accordance with ASTM D5778. Pore pressure filter elements made of porous plastic were saturated under a vacuum using silicone oil as the saturating fluid. The pore pressure element was 6 mm thick and was located immediately behind the tip (the U2 location). The cone was advanced using a 15-ton track mounted CPT rig. Tip resistance (qc), sleeve friction (fs) and dynamic pore pressure (u) data were recorded every five centimeters as the cone was advanced into the ground. The reported tip resistance (qt) was corrected for porewater effects.

Down-hole shear wave velocity (Vs) measurements in general accordance with ASTM D7400 were obtained at nominal 1-meter depth intervals during the soundings.

Shear wave velocity is defined as the speed at which propagating elastic waves travel through media. Shear wave velocity data can be interpreted for relative indications of material structure, density and stiffness.

Project drawings are provided in Appendix A. Field test results are provided in Appendix B. Laboratory test results are provided in Appendix C. Exploration and sampling procedures are provided in Appendix D.

Calculations are provided in Appendix E.

Exploration Results

The subsurface conditions encountered at the boring and sounding locations are shown on the test borings and seismic cone penetration test records in Appendix B. The test boring records represent our interpretation of the subsurface conditions based on visual examination of field samples obtained, excavation side wall materials, and laboratory classification testing on selected samples. The SCPTu sounding records represent direct measurement and interpretation of the subsurface conditions based on published correlations to strength, stiffness, behavior, and other index properties.

The lines designating the interface between various strata on the boring records represent the approximate interface location. In addition, the transition between strata may be gradual. Water levels shown on the borings without monitoring wells only represent the observations at the time of the field exploration. Ground elevations shown on the boring logs range from about 32½ to 40 feet and are based on estimations from the topographic map provided in Appendix A.

Soil Stratigraphy The subsurface soil conditions encountered in the borings and sounding were composed of man-made uncontrolled FILL material and native soils. The estimated profiles are developed based on the findings at the specific test locations, and variations between the profiles and actual subsurface conditions should be expected.

STRATUM A consists of Uncontrolled FILL (FILL) material composed of medium dense, fine and fine to medium grained, silty Sand with wood debris fragments, P-1574 1st MRSB Operational Support Facility June 15, 2023 GER Project 110-8072 Page 3 along with trace coarse and fine gravel, and clay.

Stratum A was only encountered at testing location B-1 to a depth of about 4 feet below the existing ground surface (BGS). SPT N-values in Stratum A ranged from 12 to 13 bpf, with an average of about 13 bpf. CPT point resistance (qt) ranged from about 13 to 336 tsf in this layer.

STRATUM 1 is composed of very loose to loose, fine grained, silty SAND and clayey SAND (SM, SC). Stratum 1 was encountered at all testing locations to depths ranging from approximately 12 to 17 feet BGS. The shallow borings terminated in this layer. N-values in Stratum 1 ranged from the weight of the hammer to 8 bpf, with an average of 4 bpf. CPT point resistance (qt) ranged from about 50 to 120 tsf.

STRATUM 2 is composed of very soft, fat CLAY with silt, lean CLAY with silt, and very silty CLAY (CH, CL, & CL-ML). Stratum 2 was located beneath Stratum 1 and extended to a depth of about 42 feet BGS. N-values in Stratum 2 ranged from 1 to 2 bpf, with an average of 1 bpf. CPT point resistance (qt) ranged from about 4 to 54 tsf.

STRATUM 3 is composed of loose to dense, fine, fine to medium, and fine to coarse grained, clayey SAND, silty SAND, poorly-graded SAND with silt, well-graded SAND, and silty GRAVEL with sand (SC, SM, SP-SM, SW, & GM). Stratum 3 was encountered beneath Stratum 2 and extended to the termination depth of exploration of approximately 75 feet BGS at B-1. N-values in Stratum 3 ranged from 9 to 31 bpf, with an average of 16 bpf.

CPT point resistance (qt) ranged from about 86 to 435 tsf.

Soil Survey According to the USDA NRCS web soil survey, the general project site consists of 2 mapped soil units – Baymeade fine sand and Marvyn loamy fine sand.

Baymeade fine sand composes approximately 83.2 percent of the site area and Marvyn loamy fine sand composes approximately 16.8 percent of the site area.

The web soil survey unit location and detailed description are included at the end of Appendix B.

Groundwater The groundwater table was encountered at a depth of about 9 feet below the existing ground surface at the time of drilling at locations across the entire project. A suspected perched water table was encountered at locations B-2 and B-3 at depths ranging from about 2 to 12 feet BGS and at location INF-1 at a depth of about 4¼ feet BGS. The estimated seasonal high water table

(ESHWT) was located approximately 7½ feet BGS throughout the project site.

The water levels shown on the testing records without monitoring wells represent the conditions encountered at the time frame of the exploration using mud rotary drilling and do not necessarily represent the stabilized water depths or water conditions that will be encountered during construction. Fluctuation in the water levels may occur due to variations in precipitation, evaporation, construction activity, surface runoff, tides and other local factors. Contractors should anticipate these variations in planning and scheduling the work.

Surface Materials Approximately 1½ to 3 inches of surficial soils were encountered at the testing locations. The surficial soil material consisted generally of fine grained, clayey Sand with little to some organics. The thickness and composition of surface materials should be expected to vary across the project limits.

Infiltration Testing One constant head permeability test was run at location INF-1. This test was run at a depth of approximately 2 feet BGS and had a result infiltration rate of 0.08 cm/hr measured in Stratum 1 silty SAND (SM).

Photoionization Detection Screening Each split-spoon sample was screened for petroleum related pollutants and solvent related volatile organic compounds (VOCs) immediately after recover in the field using a MiniRAE3000 photoionization detector. PID screening results ranged from approximately 0.0 ppm to

12.0 ppm throughout the project vicinity. Results are shown on the boring logs in Appendix B.

Geotechnical Laboratory Testing Geotechnical laboratory testing was conducted on selected samples recovered from the soil borings. The geotechnical laboratory program included 23 natural moisture content tests (ASTM D2216), 10 Atterberg limits tests (ASTM D4318), 10 sieve analysis tests (ASTM D6913), 2 moisture-density relationship tests (ASTM D698), 2 CBR tests (ASTMD1183), and 2 consolidation tests (ASTM D2435). Complete Geotechnical laboratory test results are provided in Appendix C and summarized in Table 1.

Chemical Laboratory Testing Chemical testing of the two composite soil samples recovered from the upper 1 to 4 feet at locations B-1 and B-3 included TCLP (VOCs, SVOCs, pesticides, P-1574 1st MRSB Operational Support Facility June 15, 2023 GER Project 110-8072 Page 4 herbicides, PCBs, and metals), TPH-DRO & GRO, PFAS, ignitibility, corrosivity, reactivity, water content, pH, soluble sulfates, chlorides, electrical resistivity, redox potential, and sulfides. Both locations had Flashpoint values greater than 200 Degrees Fahrenheit.

Location B-3 tested positive for Diesel Range organics with a result of 150 mg/Kg. We believe these are naturally occurring fine organics and not diesel organics.

Oxidation Reduction Potential results ranged from -77 to -67 millivolts. pH values ranged from 4.26 to 6.33.

Resistivity values ranged from 15,500 to 19,340 ohm-

cm. A summary of the contaminant and corrosion test results are provided in Table 2.

Table 2 Contaminant and Corrosion Test Summary

It should be noted that due to minor contaminant detection in selected soil samples, construction activities at the site may require specialized soil disposal.

The Numerical Soil Corrosivity Scale developed by the American Water Works Association (AWWA) was referenced to evaluate the corrosivity of the composite samples at test boring locations B-1 and B-3. The scale utilizes a point system in which a higher value of points indicates a higher corrosivity potential applicable to cast iron alloys. When the total points of a soil on the scale are 10 or higher, corrosive protection measures are recommended for cast iron alloys. According to the Numerical Soil Corrosivity Scale, the upper 4 feet at both test borings B-1 and B-3 have a value of 9 on the AWWA scale. Given these results, corrosive protective measures are not likely to be required at the testing locations.

Complete Chemical laboratory test results are provided in Appendix C.

Subsurface Evaluation We have conducted an evaluation of the project information, site and subsurface conditions described in the preceding sections with regard to supporting the 1st MRSB Operational Support Facility and anticipated site development.

It is anticipated that under the proposed maximum structural loads, the planned building can be supported using a conventional shallow foundation system. The anticipated allowable or design soil bearing pressure is 2000 psf.

Combined consolidation settlement from structural loads and fill placement is anticipated to be less than ½ inch.

If structural loads are increased, settlement values should be re-evaluated.

Some of the subsurface soils at bearing depth are moisture sensitive and may be prone to degradation due to weather and/or construction activities. Utilizing a weather barrier, such as a mudmat, may be necessary.

Removal and replacement of subsurface soils at foundation level may be needed if unsuitable soils are encountered. Accounting for a one foot undercut at foundation level and replacement with granular material should be an acceptable solution to unacceptable and/or weather-sensitive soils.

Subsurface drainage utilizing granular materials surrounding the foundation may be advantageous in design and construction.

Estimated total settlements of properly supported footings under the design column loads are expected to be within tolerable limits for combined loading that includes column loads of up to 35 kips, wall loads of up to 1 klf and fill depth of 2 feet. Calculations are provided in Appendix E.

Recommendations

The following recommendations are provided based on the subsurface data obtained from the site and our engineering analysis of subsurface conditions and project information furnished to us.

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Shallow Foundations The use of shallow spread footings bearing on approved existing soils or on properly constructed select fill material may be used for supporting the structure. The allowable design soil bearing pressure is 2,000 psf. A turned down slab is also an option.

Footings should bear at least 18 inches below final building grades for lateral bearing capacity considerations and for protective embedment.

Minimum footing widths are 20 inches for continuous strip footings and 30 inches for individual column footings for ease of construction and to avoid a punching failure of the supporting soils. Footing widths should be increased proportionately for the structural loads and design bearing pressure.

Total settlements of properly supported footings are expected to be within tolerable limits for combined maximum column loads of up to 35 kips, wall loads of 1 klf and fill depths of 2 ft. Combined consolidation settlement from structural loads and fill placement is anticipated to be less than ½ inch.

Calculations for settlement of wall, columns, floor loading and 2 feet of fill are provided in Appendix E.

Differential settlements on the order of one half of the estimated total settlements can be expected.

Friction factor, tan δ = 0.3, is appropriate for concrete surfaces that interface with the subsurface cohesive soils.

Fine grained subgrade soils should be excavated with a smooth-edge excavator bucket to limit disturbance of the footing subgrade soils.

Proof-rolling of fine-grained subgrade soils can lead to softening of the subgrade soils. If fine-grained soils are encountered, this work should be observed by a qualified geotechnical engineer.

An underslab drainage layer and/or perimeter drainage system may be advantageous due to the cohesive nature of the site soils.

The subsurface soils at bearing depth are moisture sensitive and may be prone to degradation due to weather and/or construction activities. Utilizing a weather barrier, such as a mudmat, may be necessary.

Prior to installing reinforcing steel and concrete, footing subgrades should be composed of relatively firm, dry suitable soils free of debris, organics, and loose material. This should be verified by a field inspector during construction. Actual soil conditions should be compared to those described in this report upon which design criteria have been based.

If unsuitable subgrade materials are encountered at the footing locations, the Engineer should be notified. The likely remediation measure for unsuitable materials would be to undercut the unsuitable materials to reach firm suitable soil and replacement with #57 crushed stone backfill to the design footing bearing elevation.

Removal and replacement of subsurface soils at foundation level may be needed if unsuitable soils are encountered. Accounting for a one foot undercut at foundation level and replacement with granular material should be an acceptable solution to unacceptable and/or weather-sensitive soils.

In drainage applications, crushed stone placed on fine-grained soils should be wrapped in a non-woven filter fabric to prevent migration of fines into the stone and limit risk of settlement.

Expansive subgrade soils exhibiting shrink/swell are not anticipated at the site.

If the soil conditions encountered are different from those described in this report, the geotechnical engineer should be contacted. Soft, wet materials and organic soils present beneath the foundation subgrade and debris fill deemed unsuitable should be removed and replaced under direction of the Engineer.

Ground Slabs Conventional ground supported concrete floor slabs appear appropriate for the proposed building.

Floating slabs should generally be jointed at column lines and along load bearing walls so that foundations and the slab can settle differentially without damage.

Subgrade modulus for the building slabs will be based in part on the quality of the imported fill material. For good quality local compacted fill over the existing subgrade soils, a subgrade modulus of 150 pci may be assumed.

A minimum 6 in thick layer of porous gravel or clean sand fill should be used directly beneath the slabs for lateral drainage of moisture. If sand is chosen, it should conform to ASTM C 33 concrete fine aggregate or equivalent. The porous fill layer should be covered with an impermeable membrane sheeting to prevent clogging during concrete placement.

P-1574 1st MRSB Operational Support Facility June 15, 2023 GER Project 110-8072 Page 6

Pavement ADT values for the proposed site have not been determined at this time.

The laboratory CBR test values on the compacted samples of sandy soils from the upper 1 to 3 feet ranged from 3.8 and 4.8.

A design CBR value of 2 is appropriate for surficial silty sands encountered at planned parking areas based on laboratory CBR values.

The following pavement sections may be appropriate for the project, but should be re-evaluated once ADTs become available:

Light Duty Asphalt Pavement (Roadway and Parking):

• 2 inches SM Surface Course

• 8 inches aggregate base course

• Tensar TX5 geogrid

• 12 inches firm compacted structural fill

Heavy Duty Asphalt Pavement (Roadway and

• 2 inches SM Surface Course

• 3 inches BM Base Course

• 8 inches aggregate base course

Heavy Duty Concrete Pavement (Roadway and

• 6 inches (PCC) Portland Cement Concrete

• 8 inches aggregate base course

Pavement materials and construction should conform with applicable UFGS specifications.

Geogrid, if used, should meet or exceed the technical specifications of Tensar TX5 geogrid or greater.

Existing pavements at the site should be removed prior to construction.

The Contractor should be responsible for maintaining site drainage over the course of construction and properly managing heavy equipment operation over prepared surfaces.

Aggregate base course should conform to NCDOT aggregate base specifications. Aggregate base course should be compacted to 95 percent of ASTM

D 1557.

At all times during construction, positive surface drainage should be maintained to prevent water accumulation on the subgrade. Pavement and subgrade deterioration often occurs from construction traffic and placement of asphalt surface courses should be delayed as long as possible to allow any base and subgrade corrections to be made as a result from heavy equipment damage.

After completion of utility installation, backfilling and rough grading, the exposed subgrade soil should be visually inspected and/or proofrolled to detect pockets of soft or otherwise unsuitable materials. Proofrolling should be conducted when possible after a suitable period of dry weather to avoid degrading an otherwise acceptable subgrade.

A loaded dump truck or similar heavy rubber-tired construction equipment should be used for proofrolling.

Any areas which show unacceptable movement during the proofrolling inspections should either be removed and replaced with select fill, scarified, dried and recompacted to acceptable levels, or improved by another means approved by the Engineer.

Prior to paving, density testing and a second proofroll should be performed on the aggregate base material to determine if localized areas have degraded due to construction traffic or moisture problems.

Unsuitable soils and/or unanticipated subgrade conditions may be encountered during construction activities based on soils encountered during the exploration, particularly soft soils and organic soils.

Unit prices and estimated bid quantities should be included in the construction estimate.

Pavement construction is best suited for the traditionally drier summer and fall months to minimize deterioration of the subgrade and base courses caused by construction traffic and exposure to the environment. We recommend the construction schedule for earthwork and paving activities be established during these times of the year to the extent possible.

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Earthwork The ground surface in the building areas should be cleared, grubbed and stripped of all vegetation, topsoil, asphalt, concrete, and other debris to reach firm soils. This work should be performed during a period of dry weather to avoid excessive deterioration of the exposed subgrade. Positive surface drainage should be maintained at all times during construction to prevent water accumulation on the subgrade.

Topsoil and unsuitable material should be removed horizontally to a nominal 5 feet beyond the outside of building lines.

Existing underground utilities within the proposed building areas should be rerouted to outside of the new building footprints. Excavations should be backfilled with compacted select material as specified in this report.

The exposed subgrade soils in the building areas should be inspected by proofrolling and visual assessment to check for pockets of soft soils prior to filling and foundation and slab construction.

Proofrolling should be conducted with a loaded dump truck or similar heavy rubber-tired construction equipment.

The construction area should be graded to provide positive surface water runoff away from the construction activity and provide temporary ditches, swales, sump pits and other drainage features and equipment as needed to maintain dry and stable soil conditions.

The contractor should be responsible for providing reasonable measures to provide drainage, protect the subgrade and implement appropriate work planning, sequencing and execution to minimize subgrade deterioration and to promote workable conditions. Measures and equipment to manage surface and subsurface water and to promote drying of the subgrade should be included in the contractor's bid.

The subgrade may be susceptible to deterioration under loads from repeated construction traffic and the subgrade will become unsuitable for pavement support even during ideal weather conditions. This will be worse when construction occurs during wet weather. Thus, adequate support for pavements will be seasonal with the need for less subgrade stabilization if the subgrade is adequately protected from surface water and construction occurs in the drier months. It is inevitable that some subgrade deterioration will occur regardless of the time of season.

Site stripping and grading should be observed by a field inspector. If unsuitable soil conditions are observed, they should be corrected by excavating and replacement with structural fill or improved by other methods that are acceptable to the Engineer.

Fill and Backfill Representative samples of each proposed fill material should be collected before filling operations begin and tested to determine maximum dry density, optimum moisture content, natural moisture content, gradation, plasticity, and CBR.

These tests are needed for quality control during construction and to determine if the fill material is acceptable.

Fill and backfill soil used in building and pavement areas should consist of non-plastic select material having a maximum of 25 percent fines by ASTM D 1140. Acceptable soil classifications by ASTM D 2487 include GW, GP, GM, SW, SP, SP-SM and some SM soils. Upper soils excavated at the site are not expected to be suitable for use as fill soils.

Crushed stone can be used for backfilling beneath footings, grade beams, etc., and should consist of washed crushed stone conforming to gradation #57 by ASTM C 33 or NCDOT specifications.

Fill and backfill soils should be spread in thin, even layers not exceeding 8 inches loose thickness prior to compaction. Each layer of soil in building and pavement areas should be compacted to achieve no less than 95 percent of the laboratory maximum dry density as determined by ASTM D 1557, the standard Proctor.

The moisture content of fill soils should be maintained within ±2 percentage points of the optimum moisture content determined from the laboratory Proctor density test. Fills should be free of debris and deleterious materials and have a maximum particle size diameter less than 2 inches.

The fill surface must be adequately maintained during fill construction. The fill surface should be compacted smooth and properly graded to improve surface runoff while construction is temporarily halted. Excavations to receive backfill should not be left open for extended periods.

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Where backfill is required in excavations that penetrate the groundwater table, an initial 6 to 12 in layer of #57 crushed stone should be used to serve as a stable base for compaction of subsequent lifts of soil fill. Groundwater should be lowered below the crushed stone elevation by pumping prior to compacting the soil.

Fill should not be placed on wet or frozen ground.

Fill which becomes softened from excess moisture should be aerated and recompacted to acceptable levels, removed and replaced with new compacted fill, or as otherwise directed by the contracting officer's representative.

Underground Utilit ies Most of the Stratum 1 soils above the groundwater table should provide satisfactory support of underground utilities as typically constructed for this type of project in this locality.

According to AWWA C-105 and corrosion testing results, the site soils should not be considered corrosive to ferrous metals.

Dewatering considerations should be addressed for excavations greater than 9 feet below the existing ground surface. Estimated seasonal high groundwater tables of about 7 feet below the existing ground surface may also be encountered at the time of construction and should be anticipated. Perched water conditions may require groundwater control at depths greater than 2 feet.

Submersible pumps should be utilized as may be needed.

Utilities that are installed at and below the groundwater table and/or in cohesive or extremely loose sandy soils should receive a minimum 6-inch bedding of gravel or crushed stone conforming to gradation #57 by NCDOT or ASTM C 33. Bedding aggregate thickness should be adjusted as needed for the soil conditions encountered and dewatering methods employed.

Loose sand soils may cave or slough if not supported. Utility excavations should be made in accordance with applicable OSHA regulations for Type C soil conditions.

Stormwater Management BMPs Estimated seasonal high water table elevations at the project site were encountered at a depth of about 7 feet below the existing ground surface, based on the testing records.

An infiltration rate of 0.083 cm/min (1.97 in/hr) was measured at depth of 2 feet BGS at testing location INF-1 within the Stratum 1 silty sands.

Low Impact Design (LID) stormwater BMP systems should incorporate underdrains that outfall to daylight or connect to existing storm drains as lower permeability clayey soils located within upper soils layers were encountered in the borings at the site and may impact permeability.

Seismic Properties Based on the USGS seismic hazard mapping web site for ASCE 7-16, the following seismic site parameters appear to be appropriate for the project site (5% damping and 2% probability of exceedance in 50 years):

Site Class D Peak Ground Acceleration 0.058

Spectral Response SMS 0.189 Spectral Response SM1 0.135 Spectral Response SDS 0.126

Spectral Response SD1 0.09 Site Coefficient Fa 1.6 Site Coefficient Fv 2.4

The site is located in an area having historically low seismic activity. The project site is not expected to be susceptible to earthquake induced slope failures.

Also, the site is not located near any known active faults that could cause surface ruptures.

Limitations The analyses and recommendations provided are based in part on project information provided to us. They only apply to the specific project and site locations discussed in this report. If our understanding of the project is incorrect or if additional information is available, you should convey the correct or additional information to us and retain us to review our recommendations.

Regardless of the thoroughness of a geotechnical exploration, there is always a possibility that conditions between borings will be materially different from those at specific boring locations. In addition, soil conditions may become altered by construction activity and the passage of time. These possibilities should be considered by the designers and contractors.

APPENDIX A

DRAWINGS

500 m

2000 ft

SITE

2712 Southern Boulevard, Suite 101

Virginia Beach, VA 23452

DRAWING NUMBERPROJECT NUMBER

VICINITY

MAP

PROJECT

LOCATION

SITE LOCATION PLAN

GERGeoEnvironmental Resources, Inc.

Consulting Engineers

Environmental Groundwater

Hazardous Materials Geotechnical

Industrial Hygiene

GeoEnvironmental Resources, Inc.

SOURCE:

USGS Topographic Map 2019 Sneads Ferry, NC

110-8072

P-1574 OSF

MCB Camp Lejeune

Stone Bay Annex Jacksonville, NC

SITE

GeoEnvironmental Resources, Inc. B-5

CBR/MW

CS

B-10/CBR

B-12

B-13

B-14/CBR/CS

110-8072 2

2712 Southern Boulevard, Suite 101

Virginia Beach, VA 23452

DRAWING NUMBERPROJECT NUMBER

TESTING LOCATION PLAN

GERGeoEnvironmental Resources, Inc.

Consulting Engineers

Environmental Groundwater

Hazardous Materials Geotechnical

Industrial Hygiene

0’ 100’ 200’

Graphic Scale 1”=100’

P1547U 1st MRSB Operataional Support Facilities MCB Camp Lejeune Stone Bay ANNEX

North Carolina

0’

0’

30’

75’

60’

150’

120’

300’

B-3

Source:

Google Maps 2023

CS

B-1

SCPTu-1

AS3502

AS3534

PC/UD

PC

CS

CBR

CPT

CPT

CPT

CPT

SCPT

B-3/PC

B-1/PC

B-4/PC

B-2/PC/CS

B-5/PC

B-6/PC

B-7/PC

B-8/PC/CS

B-11/CBR

SCPTu-1

B-2/MWBulk: Bulk Sample for CBR Testing

CS: Composite Sample for Environmental Testing

UD: Shelby Tube Sample for Consolidation Testing

SCPTu-1

B-1/UD/CS

B-3/MW

Bulldog Road

B-1/MW/CS/SH

B-3/Bulk/CS

INF-1

Soil Test Location CPTu-1

' B-2/Bulk

STRATUM A/STRATUM 1

STRATUM 2

STRATUM 3

SURFACE MATERIALS

2712 Southern Boulevard, Suite 101 Virginia Beach, VA 23452

GeoEnvironmental Resources, Inc.

DRAWING NUMBERPROJECT NUMBER

SUBSURFACE PROFILE

GeoEnvironmental Resources, Inc.

Consulting Engineers

Environmental Groundwater

Hazardous Materials Geotechnical

Industrial Hygiene

Borehole Number

B-1

Borehole Lithology

Water level reading after drilling

Denotes additional uncertainty

Water level reading during drilling

9 SPT Blows

CPT Tip Resistance

Explanation

NOTES

The subsurface conditions presented are interpreted based on the data collected at specific test locations only.

Actual subsurface conditions will likely vary from those indicated.

Elevations and strata depths shown shall be considered approximate.

STRATIGRAPHY

Stratum A: Uncontrolled FILL (FILL) material composed of medium dense, fine and fine to medium grained, silty Sand with wood debris fragments, along with trace coarse and fine gravel, and clay.

Stratum 1: Very loose to loose, fine grained, silty SAND and clayey SAND (SM, SC) Stratum 2: Very soft, fat CLAY with silt, lean CLAY with silt, and very silty CLAY (CH, CL, & CL-ML)

Stratum 3: Loose to dense, fine, fine to medium, and fine to coarse grained, clayey SAND, silty SAND, poorly-graded SAND with silt, well-graded SAND, and silty GRAVEL with sand (SC, SM, SP-SM, SW, & GM)

P-1574U 1st MRSB OSF MCB Camp Lejuene, North Carolina

110-8072

-40

-30

-20

-10

-40

-30

-20

-10

B-1

B-2

B-3

Topsoil Fill SC, Clayey Sand SM, Silty Sand

CH, High Plasticity Clay CL, Low Plasticity Clay Low plasticity, silty clay GM, Silty Gravel

SW, Well-graded Sand Slightly silty, poorly graded sand

Lithology Graphics

110-8072 4

2712 Southern Boulevard, Suite 101 Virginia Beach, VA 23452

GeoEnvironmental Resources, Inc.

DRAWING NUMBERPROJECT NUMBER

HISTORICAL SITE MAPS

GeoEnvironmental Resources, Inc.

Consulting Engineers

Environmental Groundwater

Hazardous Materials Geotechnical

Industrial Hygiene

P-1574U 1st MRSB OSF MCB Camp Lejuene, North Carolina

APPENDIX B

FIELD TEST DATA

SOIL BORING RECORDS

The enclosed soil boring records represent our interpretation of the subsurface conditions encountered at the specific boring locations at the time explorations were made based on visual examination of the field samples obtained and laboratory classification testing on selected samples if performed. The lines designating the interface between various strata on the boring records represent the approximate interface location. In addition, the transition between strata may be more gradual than indicated. Water levels shown represent the conditions only at the time of the field exploration. It is possible that soil and groundwater conditions between the individual boring locations will be different from those indicated. Boring surface elevations and horizontal position, if shown, shall be considered approximate and referenced to the project datum shown on the plans or described in the geotechnical report unless noted otherwise.

BORING LOG LEGEND

after Terzaghi and Peck, 1968 after D. U. Deere, 1963, 1967

Resistance of a standard 2-inch O.D., 1.375-inch I.D. split spoon sampler driven by a 140 pound hammer free-falling 30 inches.

HARDNESS WEATHERING

Very Hard - Breaking specimens requires several hard hammer blows

- Hard hammer blow required to detach specimensHard

- Light hammer blow required to detachModerately Hard specimens

- May be scratched 1/16" deep by a knife or nail, breaksMedium into several pieces by light hammer blow

- Can be gouged readily by knife or nail, corners and edgesSoft broken by finger pressure

- May be carved with a knife and readily broken by fingerVery Soft pressure

Fresh - Fresh rock, bright crystals, no staining

- Minimum stainaing and discoloration, open joints containSlight clay

- Significant portions of rock shows staining andModerate discoloration, strong rock fragments

- All rock shows staining, rock fabric evident but reducedSevere strength

- All rock shows staining, rock mass effectivelyVery Severe reduced to soil with strong rock fragments remaining

- Rock reduced to soil with rock fabric not discernableComplete

DIAGNOSTIC

DESCRIPTION

Very Poor Poor Fair

Good Excellent

ROCK PARAMETER

FIELD/LAB RATIO

0.15 0.20 0.25

0.30 to 0.70

0.70 to 1.00

SPACING

Less than 2" 2" to 1' 1' to 3'

3' to 10' More than 10'

ROCK QUALITY

FRACTURES, JOINT SPACING AND BEDDING

RQD (%)

0 - 25 25 - 50 50 - 75 75 - 90 90 - 100

JOINTS

Very Close Close Moderately Close Wide Very Wide

BEDDING

Very Thin Thin Medium Thick Very Thick

CORRELATION OF RELATIVE DENSITY AND CONSISTENCY

WITH STANDARD PENETRATION TEST (SPT) RESISTANCE (ASTM D1586)

FIELD MEASURED SPT RESISTANCE (N) IN BLOWS PER FOOT OR PER 0.3 m

0 - 4 5 - 10 11 - 30 31 - 50

51 +

RELATIVE DENSITY

SAND & GRAVEL

Very Loose Loose

Medium Dense Dense

Very Dense

0 - 2 3 - 4 5 - 8

9 - 15 16 - 30 31 - 50

51 +

CONSISTENCY

SILT & CLAY

Very Soft Soft Firm Stiff

Very Stiff Hard

Very Hard

SPT

N

SPT

N

KEY TO DRILLING SYMBOLS AND ABBREVIATIONS

Undisturbed Sample (ASTM D1587)

Split Spoon Sample(ASTM D1586)

Water Table after Stabilization Period

Water Table at Time of Drilling

PP Pocket Penetrometer (tsf)

M.R. Mud Rotary Wash Drilling

H.S.A. Hollow Stem Auger Drilling

Loss of Drilling Fluid

Boring Cave In

Seepage into Borehole Rock Coring (ASTM D2113)

Core Recovery (%)REC

Rock Quality Designator (%)RQD

Weight of Hammer (N = 0)SPTW.O.H.Approximate Strata Change Depth Different Soil Classification Type

Approximate Strata Change Depth Similar Soil Classification Type

SOIL CLASSIFICATION CHART (ASTM D2487)

COARSE

GRAINED

SOILS

MORE THAN 50%

OF MATERIAL

IS LARGER

THAN NO. 200

SIEVE SIZE

FINE

GRAINED

SOILS

OTHER

SOILS

MORE THAN 50%

OF MATERIAL

IS SMALLER

THAN NO. 200

SIEVE SIZE

GRAVEL

AND

GRAVELLY

SOILS

MORE THAN 50%

OF COARSE

FRACTION

RETAINED ON

NO. 4 SIEVE

SAND

AND

SANDY

SOILS

MORE THAN 50%

OF COARSE

FRACTION

PASSING ON

NO. 4 SIEVE

SILTS

AND

CLAYS

HIGHLY ORGANIC SOILS

UNCONTROLLED FILLS

DECOMPOSED OR PARTIALLY

WEATHERED ROCK

CLEAN

GRAVELS

(LITTLE OR NO

FINES)

GRAVELS

WITH FINES

(APPRECIABLE

AMOUNT OF FINES)

CLEAN SANDS

(LITTLE OR NO

FINES)

SANDS WITH

FINES

(APPRECIABLE

AMOUNT OF FINES)

LOW PLASTICITY

LIQUID LIMIT

LESS THAN

HIGH PLASTICITY

LIQUID LIMIT

GREATER THAN

WELL-GRADED GRAVELS,

GRAVEL - SAND MIXTURES,

LITTLE OR NO FINES

POORLY-GRADED GRAVELS,

GRAVEL - SAND MIXTURES,

LITTLE OR NO FINES

SILTY GRAVELS, GRAVEL -

SAND - SILT MIXTURES

CLAYEY GRAVELS, GRAVEL -

SAND - CLAY MIXTURES

WELL-GRADED SANDS,

GRAVELLY SANDS, LITTLE OR

NO FINES

POORLY-GRADED SANDS,

GRAVELLY SAND, LITTLE OR

NO FINES

SILTY SANDS, SAND - SILT

MIXTURES

CLAYEY SANDS, SAND - CLAY

MIXTURES

INORGANIC SILTS, CLAYEY SILTS,

SILT-VERY FINE SAND MIXTURES,

ROCK FLOUR

INORGANIC CLAYS OF LOW TO

MEDIUM PLASTICITY,

GRAVELLY, SANDY, SILTY, &

LEAN CLAYS

ORGANIC SILTS AND ORGANIC

CLAYS OF LOW PLASTICITY

INORGANIC SILTS AND MICACEOUS,

DIATOMACEOUS AND ELASTIC

SILTY SOILS

INORGANIC CLAYS OF HIGH

PLASTICITY, FAT CLAYS

ORGANIC CLAYS OF MEDIUM TO

HIGH PLASTICITY, ORGANIC

SILTS

PEAT, HUMUS, MUCK, SWAMP SOILS

WITH VERY HIGH ORGANIC

CONTENTS

TRANSITIONAL MATERIAL BETWEEN SOIL AND

ROCK WHICH MAY RETAIN THE RELICT

STRUCTURE OF THE PARENT ROCK

DISTURBED SOILS WITH POSSIBLE DEBRIS

AND RUBBLE, OLD CONSTRUCTION

WASTES, NON-ENGINEERED BACKFILLS

MAJOR DIVISIONS

SYMBOLS

GRAPH LETTER

TYPICAL

DESCRIPTIONS

GW

GP

GM

GC

SW

SP

SM

SC

ML

CL

OL

MH

CH

OH

PT

PLASTICITY INDEX (PI) RELATIVE TO SWELL POTENTIAL

0 - 4 4 - 15

15 - 30 31+

None Slight or Low

Medium to High High to Very High

ADDITIONAL RELATIVE DESCRIPTIVE VALUES

Trace < 10% Little 10 - 20%

Some 20 - 30% Modifier > 30%

4.75 mm to 19.0 mm (#4 - 0.75 in.)

PARTICLE SIZE IDENTIFICATIONPLASTICITY CHART (ATTERBERG LIMITS)

BOULDERS:

COBBLES:

GRAVEL: Coarse -

Fine -

SANDS: Coarse -

Medium -

Fine -

SILTS & CLAYS:

Greater than 300 mm (12 in.)

75 mm to 300 mm (3 - 12 in.)

19.0 mm to 75 mm (0.75 - 3 in.)

2.00 mm to 4.75 mm

0.425 mm to 2.00 mm

0.075 mm to 0.425 mm

Less than 0.075 mm

Surficial Soil - 3" Sampled as clayey sand, dark brown, fine, with little to some organics, moist Uncontrolled Fill Sampled as silty sand, dark brown to reddish brown, fine, with little to some organics (woody debris), trace coarse sand and fine gravel, moist Uncontrolled Fill Sampled as silty sand, tan, fine to medium, with trace clay, moist Clayey SAND (SC) Very loose to loose, tan mottled gray, fine, with trace to little silt, moist to wet

Silty SAND (SM) Very loose, tan mottled gray, fine, with trace to little clay, wet

Fat CLAY with Silt (CH) Very soft, gray, wet

Sandy Lean CLAY (CL) Very soft, gray, with trace to little silt, wet

PID = 0.2

Composite sample taken from 1-4 feet

PID = 1.3

Estimated

SHWT: 7.5

Feet 8-20 feet noted with alternating sand/clay layers

P.P. = 0.2 Tsf

TEST BORING RECORD

Penetration Resistance (blows/foot) S P T

Elevation m

Geotechnical, Environmental, Hazardous Materials, Groundwater & Industrial Consultants

Ground WaterMaterial DescriptionLith-ology Depth ft m ft 0 25 50

GER Project Number: 110-8072

Client: Bamforth Engineers+Surveyors

Uncorrected

Boring #:

Project: P-1574U 1st MRSB OSF

Location: Stone Bay Annex, Camp Lejeune, NC

Date Drilled: 12/15/2022

Driller: Fishburne

Logged By: Douglas Suttle Jr.

Drill Method: 4" Mud Rotary

Hammer: Automatic Rig: CME 45C

Datum: NAD83

Datum: WGS84

Surface Elev. (ft): 39.8

Vertical Datum: NAVD88

B-1 (Page 1 of 3)

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S

Latitude: 34.57664 Longitude: -77.43731

GeoEnvironmental Resources, Inc. 2712 Southern Boulevard, Suite 101 Virginia Beach, VA 23452 757-463-3200 www.geronline.com

Comments N

Northing (ft): 304556.8 Easting (ft): 2470378.9

T E

S T

B O

R

IN

G R

E C

O R

D

2.

G P

J G

E R

.G D

T

/6 /2

Sandy Lean CLAY (CL) Very soft, gray, with trace to little silt, wet (continued)

Very Silty CLAY (CL-ML) Very soft, grayish green, wet

Lean CLAY with Silt (CL) Very soft, grayish green, wet

Silty SAND (SM) (Yorktown Formation) Dense, grayish green, fine to medium, with trace shell fragments, wet

Silty GRAVEL with sand (GM) (Yorktown Formation) Dense, dark olive green, fine, with little fine to coarse sand, wet Well Graded SAND (SW) (Yorktown Formation) Dense, grayish green, fine to coarse, wet Poorly-graded SAND with Silt (SP-SM) (Yorktown Formation) Medium dense, gray, fine to coarse, with trace to little shell fragments and fine gravel-sized shell fragments, wet

P.P. = 0.2 Tsf

P.P. = 0.3 Tsf

P.P. = 4.1 Tsf

PID = 0.4

PID = 0.1

TEST BORING RECORD

Penetration Resistance (blows/foot) S P T

Elevation m

-1

-2

-3

-5

-10

Geotechnical, Environmental, Hazardous Materials, Groundwater & Industrial Consultants

Ground WaterMaterial DescriptionLith-ology Depth ft m ft 0 25 50

GER Project Number: 110-8072

Client: Bamforth Engineers+Surveyors

Uncorrected

Boring #:

Project: P-1574U 1st MRSB OSF

Location: Stone Bay Annex, Camp Lejeune, NC

Date Drilled: 12/15/2022

Driller: Fishburne

Logged By: Douglas Suttle Jr.

Drill Method: 4" Mud Rotary

Hammer: Automatic Rig: CME 45C

Datum: NAD83

Datum: WGS84

Surface Elev. (ft): 39.8

Vertical Datum: NAVD88

B-1 (Page 2 of 3)

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Latitude:…