T10_11_AFRH_Geotechnical Report_221014.pdf

GEOTECHNICAL ENGINEERING SERVICES

ARMED FORCES RETIREMENT HOME –

SHERIDAN BUILDING RENOVATIONS

WASHINGTON, DC

Submitted To:

AE-Works 1655 N. Ft. Myer Drive, Suite 630 Arlington VA, 22209

Austin R. Spencer, EIT J. Steven Donahue, PE Staff Geotechnical Engineer Project Geotechnical Engineer

October 14, 2022

AEWLA22050

TABLE OF CONTENTS

SECTION PAGE

1. EXECUTIVE SUMMARY

2. INTRODUCTION

2.1. PROJECT DESCRIPTION

2.2. INFORMATION REVIEWED

2.3. EXISTING SITE CONDITIONS

2.4. OBJECTIVES

3. FIELD AND LABORATORY WORK

3.1. PERMITTING

3.2. FIELD WORK

3.3. LABORATORY WORK

4. SUBSURFACE CHARACTERISTICS

4.1. GEOLOGY

4.2. SUBSURFACE STRATIGRAPHY

4.3. GROUNDWATER

5. ANALYSES AND RECOMMENDATIONS

5.1. FOUNDATIONS

5.1.1. SHALLOW SPREAD FOOTINGS – WEST ENTRANCE

5.1.2. GROUTED HELICAL PIERS - ANNEXES

5.2. GROUND FLOOR SLAB

5.3. SEISMIC SITE CLASSIFICATION

5.4. GROUNDWATER AND SURFACE WATER MANAGEMENT

5.5. EARTHWORK

5.6. EXISTING AND PROPOSED UTILITIES

6. LIMITATIONS

APPENDICES

APPENDIX A – Location Sketches (2)

APPENDIX B – Boring Logs (7)

APPENDIX C – Geotechnical Laboratory Test Results (17)

APPENDIX D – Important Information About This Geotechnical Engineering Report (2)

AEWLA22050 October 14, 2022 Sheridan Building Renovations

AE Works Washington, DC

1. EXECUTIVE SUMMARY

Pennoni has completed our geotechnical evaluation for the proposed renovation of the existing Sheridan Building located within the Armed Forces Retirement Home (AFRH) located at 140 Rock Creek Church Road NW in Washington D.C. The executive summary below should be used in conjunction with the body of the report.

Proposed Construction and Site Conditions Section(s)

Proposed Construction

Renovations consist of façade treatment, construction of an additional floor above three low-rise annexes located on the east side of the building, upgrading utility services, west entrance renovations, and landscaping.

2.1

Field Work Seven SPT borings advanced to depths ranging from 6.5 to 35 feet below existing grades.

Two Borings located within Center Annex, two borings at existing west entrance, and three borings around perimeter of existing low-rise annexes.

3.2

Surface Materials

Approximately 6 inches of concrete within Central Annex, 3 to 7 inches of bituminous asphalt at perimeter of low-rise annexes, and 9 to 9.5 inches of concrete at existing west entrance.

4.2

Subsoils

Stratum F – very soft to very stiff clay or medium dense to dense sand (4.5 – 12.4 feet thick); Stratum A* – soft to very stiff Clay (0.5 – 13.0+ feet thick); Stratum B – very loose to dense Sand (5.0 – 12.5 feet thick); Stratum C* – very soft to very stiff Silt (4.0 – 7.0 feet thick) [*Not encountered in all borings.]

4.2

Groundwater

(GW)

Groundwater was encountered at the project site in Borings “B-2,” “B-4” through “B-6” and “B-8” at depths ranging from 15.0 to 25.0 feet (Elev. 275.0 to 299.5 feet, NAVD88) below the existing ground surface.

4.3

Recommendations Section(s)

Seismic Site Class

Site Class E – a soft clay soil profile in accordance with ASCE-7.

5.3

Lift Thickness & Compaction Requirements

Granular Soil – 10 to 12 in. thick layers loose measure; Foundations and floor slab 98% (standard proctor) or 95% (modified proctor) depending on compaction equipment used. 5.5

Foundations

- Spread Footings with densification in place or localized undercuts as needed designed assuming a net, allowable bearing capacity of 3,000 psf for the proposed West Entrance renovations

- Grouted helical piers to depths of 15 to 35 feet below footing elevation for the low-rise annexes with estimated allowable capacities ranging from approximately 6 to 32 kips in compression and tension.

5.1, 5.1.2

Settlement

Total and differential settlements due to structural loading are anticipated on the order of less than 1 inch and 0.5 inches, respectively for the proposed west entrance.

Performance specifications should be provided to specialty contractors to achieve tolerable settlements for helical piers

5.1.1 , 5.1.2

Slab-On-Grade Provided the subgrade is properly prepared, constructing the floor slab on grade is considered feasible. A modulus of subgrade reaction of 125 pci can be used in slab design.

5.2

Frost Depth 30 inches below finished exterior grades or otherwise protected against frost action in accordance with the DCMR 12.

5.1.1 , 5.1.2

Subsurface Utilities

Existing utilities noted in the field included (but may not be limited to): water, electric, sewer and unknown lines located around the perimeter of the existing building and floor drains located underneath the Central Annex slab on grade.

5.6

2. INTRODUCTION

2.1. PROJECT DESCRIPTION

The project consists of renovation of the existing Sheridan Building located within the AFRH located at 140 Rock Creek Church Road NW in Washington D.C., as indicated on the Site Location Sketch, SK-1, provided in Appendix A. We understand the renovations consist of façade treatment, construction of an additional floor above three low-rise annexes, upgrading utility services, west entrance renovations, and landscaping. The proposed floor additions will be located on the eastern side of the building within the north, central, and south annex wings of the existing Sheridan Building. The floor additions generally consist of new apartment style rooms. The west entrance modifications consist of new vestibule and trellis architectural treatment located on the western side of the building. As of the issuance of this report the preferred renovations consist of new spread footings and columns located throughout the existing north, central, and south annex wings. We understand maximum anticipated single-column service loads are approximately 50 kips for the proposed North and South Annexes and approximately 100 to 150 kips for the proposed Central Annex.

Pennoni is also providing survey and civil/site development services for this project.

2.2. INFORMATION REVIEWED

To assist with the development of this proposal we reviewed the following:

• A drawing package titled “Armed Forces Retirement Home BPA Call 01- Sheridan Bldg. 4th Floor – Bridging Design for Design/Build,” prepared by AE Works, dated December 4, 2020;

• An undated drawing package titled “AFRH Sheridan Renovation,” prepared by AE Works;

• An undated document titled “1FL Exp- Option 1” provided by Woods Peacock identifying preliminary renovation foundation options/locations;

• An adapted drawing prepared by Woods Peacock showing proposed footing locations titled “Foundation and Ground Floor Plan – Additions & Renovations to Sheridan Building United States Soldiers’ and Airmens’ Home,” prepared by U.S. Army Engineer District, Baltimore Corps of Engineers, dated July 1992; and

• A topographic survey performed by Pennoni on August 30, 2022.

2.3. EXISTING SITE CONDITIONS

Based on our review of the above referenced documents, available aerial photography, and observations made during our field exploration, it is our understanding that the project site consists of the existing Sheridan Building located in the northeast corner of the AFRH campus. The building is bordered by trees and existing parking lots to the north, parking spaces and Sheridan Drive to the east, open grass areas and Eisenhower Drive to the south, and Grant Drive to the west. Based on the above-mentioned topographic survey the site generally slopes downward from west to east with elevations ranging from approximately 319 feet (NAVD88) at the existing entrance to approximately 300 feet (NAVD88) in the parking lot east of the annexes.

2.4. OBJECTIVES

The objectives of our geotechnical engineering services were to determine subsurface conditions at the project site, evaluate these conditions with respect to the proposed construction, and present our conclusions and recommendations regarding:

• foundation design of the proposed structures, including discussion of alternate solutions, if necessary;

• design frost depth;

• discussion of potential for consolidation and/or differential settlements of substrata encountered;

• “general procedure” soil Site Class based on applicable IBC requirements;

• ground floor slab design considerations;

• groundwater conditions and their influence on design and construction;

• subgrade preparation;

• removal or treatment of objectionable material;

• use and treatment of in-situ materials for controlled fill; and

• quality assurance and field-testing and observations during construction.

3. FIELD AND LABORATORY WORK

3.1. PERMITTING

Prior to performing our field exploration summarized below, Pennoni obtained soil boring permit SB2200416 from the DC Department of Energy and Environment (DOEE). The permit applications included a Well Construction Work Plan dated August 30, 2022, outlining our proposed work procedure, site restoration, and reporting requirements. Authorization was obtained on September 1, 2022, and September 7, 2022, from DOEE and Department of Consumer and Regulatory Affairs (DCRA), respectively.

3.2. FIELD WORK

Pennoni performed seven Standard Penetration Test (SPT) borings between September 19 and September 21, 2022, labeled “B-1,” “B-2,” and “B-4” through “B-8.” Borings “B-1” and “B-2” were performed within the existing Central Annex wing of the building. Borings “B-4” through “B-8” were performed along the exterior of the building adjacent to proposed renovations. Proposed Boring “B-3” was not performed due to conflict with existing utilities. Borings were performed to depths ranging from 6.5 to 35 feet below the existing ground surface. Continuous sampling was performed to a depth of 10 feet below the existing ground surface and then in five feet intervals to the termination or refusal depths for Borings “B-4” through “B-8”, whichever depth was encountered first. Refusal to spoon advanced was encountered in Borings “B-1” at a depth of approximately 6.5 feet below existing slab on grade. Boring “B-1” was unable to be offset due to limited access within the building to an alternative location.

At the conclusion of drilling, Borings “B-2” and “B-4” through “B-8” were backfilled with bentonite grout and excess soil cuttings were placed in 55-gallon drums in accordance with the DOEE soil boring permit conditions.

Boring “B-1” was backfilled with pea gravel as groundwater was not encountered and was terminated at depth not exceeding 10 feet. The 55-gallon drums were left onsite at a location approved by the Client and are scheduled to be removed pending scheduling from our drilling subcontractor for unregulated disposal based upon the results of environmental testing (see below). Upon conclusion of grouting, the existing concrete/asphalt were patched with rapid set concrete and bituminous concrete asphalt, respectively. Test borings were performed by DMY Engineering Consultants (DMY) using a tripod rig with manual hammer for Borings “B-1” and “B-2” and a truck mounted auger rig with 3¼ inch hollow stem augers and an automatic hammer for Borings “B-4” through “B-8” to the specified termination depths. Our S. Donahue, PE directed the field work and A. Spencer, EIT observed the test drilling. The test boring locations are depicted on the Boring Location Sketch, SK-2, provided in Appendix A. Test boring logs are provided in Appendix B.

3.3. LABORATORY WORK

Following conclusion of the SPT drilling, the soil samples were delivered to our laboratory for testing. The geotechnical laboratory program consisted of the following:

• Moisture Content (ASTM D 2216) 10 tests

• Sieve Analysis (w/out hydrometer, ASTM D 422) 10 tests

• Atterberg Limits (ASTM D 4318) 5 tests

Samples from the excess soil spoils generated during our exploration were obtained by DMY during drilling operations and were delivered to Phase Separation Science for environmental testing to determine soil disposal requirements in accordance with the permit requirements of DOEE Soil Boring Permit SB2200416.

Samples for geotechnical laboratory testing were selected by Pennoni’s geotechnical engineer and samples for environmental testing to determine soil disposal requirements were selected by DMY. Results of the laboratory testing are provided in Appendix C of this report.

4. SUBSURFACE CHARACTERISTICS

4.1. GEOLOGY

According to the Geologic Map of Washington West Quadrangle, DC, developed by the U.S. Geological Survey group in 1995, the site is in an urbanized area in D.C., and lies across the Fall Zone, which separates the Appalachian Piedmont on the west and the Atlantic Coastal Plain on the east. The Piedmont is underlain by metamorphosed rocks of sedimentary, volcanic, and plutonic origin. The Coastal Plain is underlain by generally large bodies of sand and gravel with lesser amounts of silt and clay. More specifically, the site is located within the Potomac Group, which generally consists of variegated gravel, sand, silt and clay, with more coarse-grained sand and gravel-filled lenses, with mainly fine-grained sand and thick clay lenses above basal beds.

Beds at or near the base reflect the composition of the underlying adjacent basement rocks; that is, they contain feldspathic sand, smectic clay, and clasts of crystalline rocks. Higher in the Potomac Group, the bulk composition tends to be kaolinitic clay. The quartz-rich beds were probably derived from erosion and reworking of older Potomac Group beds farther west.

According to the U.S. Department of Agriculture (USDA) Web Soil Survey the area of interest within the project site primarily consists of Woodstown Sandy Loam (WdaB) and Sassafras Urban/Gravelly Sandy Loam (ScB/ScC/ScD). WdaB consists of sandy loam underlain by fine sandy loam and loamy sand with convex to concave down slope shapes. WdaB is considered hydrologic soil group C. Depth to water table is approximately 20 to 40 inches below existing ground surface with depth to restrictive features exceeding 80 inches. ScC/ScD consists of gravelly sandy loam underlain by sandy loam, loam, and loamy sand and is considered hydrologic soil group B. Depth to water table is greater than 80 inches below existing ground surface with depth to restrictive features exceeding 80 inches.

4.2. SUBSURFACE STRATIGRAPHY

Subsurface stratigraphy encountered by the test borings generally consists of a surficial layer of asphalt pavement or concrete generally underlain by a cohesive very soft to very stiff or granular, medium dense to dense fill material. The fill material was generally underlain by a soft to very stiff clay layer interbedded with very loose to dense sand/gravel or a very soft to very stiff silt layer. The borings were generally terminated within Stratum A. For descriptive purposes the soil layers can be classified as follows:

Stratum Approximate Thickness (ft)

Description

USCS/USDA

Classification

P 0.25 - 0.75 3 to 7 inches Bituminous Asphalt Concrete

OR

6 to 9 inches of Concrete

F[1] 4.5 – 12.4

FILL: Brown to black silty clay, little to and fine to medium to coarse sand, trace fine gravel, trace concrete debris, (moist, very soft to very stiff)

OR

FILL: Brown to tan medium to fine to coarse SAND, trace to some fine to coarse gravel, little silt (moist, medium dense to dense)

A[2] 0.5 – 13.0 + Orange to gray to brown to tan to maroon silty CLAY, little fine to medium sand (moist to saturated, soft to very stiff)

CL / CH

B[3] 5.0 – 12.5

Tan to brown to gray medium to fine to coarse SAND, trace to and silt/clay, trace to little fine gravel (moist to saturated, very loose to medium dense)

OR

Tan to brown fine to coarse GRAVEL, some medium to coarse to fine sand, trace silt (moist, dense)

SP / SM / SC

GP

C[4] 4.0 – 7.0 + Gray to black clayey SILT, trace to some fine to medium sand (moist to saturated, very soft to very stiff)

ML

Notes:

[1] Stratum F was not fully penetrated in Boring “B-1” [2] Stratum A was not encountered in Boring “B-1” and was not fully penetrated in Borings “B-4” through “B-8” [3] Stratum B was only encountered in Borings “B-4” through “B-8” [4] Stratum C was only encountered in Borings “B-2,” “B-4,” and “B-5” and not fully penetrated in Boring “B-2”

4.3. GROUNDWATER

Groundwater observations were made in each boring during sampling and shortly after completion of drilling.

Groundwater was encountered at the project site in Borings “B-2,” “B-4” through “B-6” and “B-8” at depths ranging from 15.0 to 25.0 feet (Elev. 275.0 to 299.5 feet, NAVD88) below the existing ground surface.

Groundwater was not encountered within Borings “B-1” and “B-7.” Groundwater observations are for the times indicated and may not be indicative of seasonal or daily variations in the groundwater levels. Seasonal variations on the order of several feet should be anticipated.

Results from the field exploration were reviewed for soil composition and redoximorphic features (RMF). RMF, are defined as color patterns in a soil that are caused by loss or gain of pigment compared to the matrix color due to oxidation/reduction of iron and or manganese coupled with their removal, translocation, or accrual typically indicating the seasonal high-water table or a perched water condition. RMFs were observed within Borings “B-4,” “B-5,” and “B-7” at approximate depths ranging from 10 to 20 feet below the existing ground surface (Elev. 290.0 to 296.0 feet, NAVD88).

5. ANALYSES AND RECOMMENDATIONS

5.1. FOUNDATIONS

Factors effecting foundation design, construction, and performance for this project consist of variable subsurface soil consistency, loose/soft fill material, compressible clay layers, and site access constraints. Based on our understanding of the proposed renovations, we anticipate the proposed foundations will bear within the Strata F/A soft to stiff clay. At this site, soft/loose to firm/medium dense soils were encountered to depths of approximately 10 to 20 feet below existing grade which results in shallow foundation construction being impractical due to the relatively low allowable bearing capacity resulting in excessively large foundations and/or significant settlement in the general vicinity of the annexes. Ground improvement or soil exchange is not considered feasible for the project as the site is developed and the foundations for the annex renovations are proposed within the existing structures which limit access to foundation locations. Therefore, shallow foundations or helical piers were considered for the proposed renovations for the west entrance and annex, respectively, as the entrance renovations are relatively lightly loaded, and the helical piers can be installed in areas requiring tight access. The following are recommendations for foundation systems based on our evaluation of these factors and our experience.

5.1.1. SHALLOW SPREAD FOOTINGS – WEST ENTRANCE

The west entrance modifications consist of new vestibule and trellis architectural treatment located on the western side of the building. Anticipated bearing strata consist predominantly of stiff clay of Strata F/A. We recommend designing the foundations for a maximum, net allowable bearing capacity of 3,000 pounds per square foot (psf) for the proposed vestibule and trellis foundations. Based on the subsurface conditions encountered and an allowable foundation bearing pressure of 3,000 psf we estimate total settlement on the order up to 1 inch, with differential settlement less than 0.5 inches across similarly founded foundations.

Due to the variability in the consistencies/relative densities of the near surface/bearing elevation subsoils, ground modification through densification in place and/or undercutting of the soft soils of Strata F/A may be required in order to improve the subgrade, create a uniform bearing stratum, and minimize total and differential settlements. Excavated soils should be replaced with suitable load-bearing structural fill placed in layers and compacted as outlined in the Earthwork section below.

Continuous and isolated footings should be at least 2 feet wide and 3 feet square, respectively, to prevent localized shear failure in the soil. The subgrades of all foundations exposed to freezing temperatures during construction and/or the life of the structure should be established at least 30 inches below adjacent to exposed grades or otherwise protected against frost action in accordance with the District of Columbia Municipal Regulations (DCMR) 12. High plasticity clay was encountered within Stratum A but is not expected to be encountered at vestibule and trellis footing bearing elevations.

If high plasticity soils are encountered, we recommend that the material be removed to a depth of 4 feet below the exterior grade or until the underlying sand is encountered, followed by backfill of the undercut with granular structural fill compacted in accordance with the Earthwork section below. Foundation subgrades should be checked by a representative of the Geotechnical Engineer to confirm conditions suitable for support of the design bearing pressure. Where an area is questionable, it should be further explored and/or remedied by removal and replacement of unsuitable material.

5.1.2. GROUTED HELICAL PIERS - ANNEXES

Based on the above referenced historical drawings the annexes have an approximate finished floor elevation of 304 feet (NAVD88) with existing shallow foundations bearing at elevations ranging from approximately 297.5 to 299.0 feet (NAVD88). It is assumed that new shallow foundations for the proposed Annexes are anticipated to bear at similar elevations. Anticipated bearing strata consist predominantly of very soft to stiff clay of Strata F/A. Based on the encountered subsurface soils it is our opinion that shallow foundations are not feasible for the renovations due to low allowable bearing capacity resulting in excessively large footings and/or determinantal post construction settlement due to the above-mentioned structural loadings and very soft compressible clays.

It is our opinion that grouted helical piers can be considered for support of the proposed additional floors.

This type of foundation system is capable of being constructed in “limited access” locations such as the ground floor of the existing annexes. Grouted helical piers are a deep foundation system that employs the use of a grout column that encases a metal shaft with one or more helices attached. Helical piers are rotated into competent soils while an axial load is applied to the shaft. After the lead section is installed, a displacement plate with subsequent extensions are installed until the termination depth is achieved.

Flowable grout is pumped during the installation procedure to encase the shaft as the extensions are added until a termination depth is achieved. The design bearing capacity is confirmed by measuring the torque applied to the shaft by the installation equipment as well as static load testing (if applicable). The helical piers are incorporated into proposed foundations using a concrete pile cap or be attached to existing foundations with a bracket, and the structural loads are transferred to competent soils at an appropriate depth through the helical piers. Helical piers typically develop little lateral resistance but may be improved by providing battered piers as necessary, up to 30 degrees from vertical. Grouted helical piers provide an increase in the buckling resistance of the pier (as compared to non-grouted helical piers), as the pier’s slenderness ratio is inherently large due to the length of the pier and the relatively small cross-sectional area of the pier. The encasement of the steel shaft with grout also provides a benefit against corrosive resistance from the soil.

An analysis was performed assuming a grouted 2.875-inch diameter steel shaft and a 12 in./ 14 in./ 14 in.

(helix diameter) configuration with an 8-inch diameter grout encasement of the entire shaft excluding the lead section at several depths for use in foundation design for the proposed renovations. Based on the analysis the helical piers can develop axial and tensile capacities as shown in the table below, for lengths on the order of 15 feet to 35 feet below bottom of footing elevation terminating in stiff to very stiff Strata A/C soils. The length of the pier will be dependent on the depth of the existing footing elevation and the capacity required based on the anticipated structural loading. The piers should be spaced a minimum of 3-times the largest helix diameter to prevent reduction in capacity due to group effects.

Helix Configuration

Loading Condition Installation Depth

15 feet 25 feet 35 feet

12/14/14 in.

Allowable Capacity – Compression (kips) 6 22 32

Allowable Capacity – Tension (kips) 6 18 32

Min. Helix Installation Torque (ft-lbs) 1,435 5,075 7,175

The capacity estimates above are based on a factor of safety of 3.0 for compression and tension. If higher capacities are desired, the factor of safety in compression can be reduced to 2.0 if the contractor performs a minimum of one static load test in accordance with ASTM D1143 in order to verify the as-constructed pier capacity. The static load test is to be performed on a non-production pier to confirm the capacity.

The estimated torque required to reach the estimated capacities is also provided in the table above. We note that the results of a load test will only be good for the specific type of pier installed and no substitutions should be permitted without performing another static load test to confirm the axial capacity of an alternate pier.

Based on our analysis, we recommend contract documents specify that the contractor is to provide helical piers capable of achieving the necessary allowable compressive and uplift (tension) capacities and settlement being indicated from the design of the proposed piers signed and sealed by a Professional Engineer licensed in the District of Columbia. The contractor should also have a minimum of 5 years of successful helical pier experience using the type of helical pier specified herein.

5.2. GROUND FLOOR SLAB

The proposed subgrades are anticipated to primarily consist of fine-grained clay of Strata F/A and/or newly placed structural fill. The Stratum A high plasticity clay is expected to be encountered at subgrade elevations, if encountered we recommend that the material be removed to a depth of 4 feet below exterior grades followed by backfill of the undercut with granular structural fill compacted in accordance with the Earthwork section below. Provided the subgrades are prepared as discussed in the Earthwork section below, the concrete slabs on grade can be designed using a modulus of vertical subgrade reaction (kv) of 125 pci. We recommend that the slabs be designed as “fully floating” (not connected to the structural elements of the building) in order to reduce potential cracking due to differential settlement between the building’s structural elements and slab on grade. A 4 to 6-inch-thick free-draining granular base course should be placed beneath the slabs to provide a uniform bearing surface and to aid in the proper curing of the concrete.

5.3. SEISMIC SITE CLASSIFICATION

The borings disclosed subsurface conditions generally described according to the Table 20.3-1 of ASCE 7 and referenced in Section 1613.3 of the 2018 International Building Code (IBC) as having a soil-profile corresponding to Site Class E – a soft clay soil profile. Site Class determination is based on the properties in the upper 100 feet of the ground surface. The test borings performed herein were advanced to a maximum depth of 35 feet. Values beyond 35 feet were estimated based on our local experience in this area. Based on Figures 22-1 and 22-2 of the ASCE-7, parameters Ss and S1 for the site can be assumed to be 0.133g and 0.043g, respectively.

5.4. GROUNDWATER AND SURFACE WATER MANAGEMENT

The groundwater observations made in the borings suggests that free-standing groundwater is not anticipated in excavations for the proposed renovations. In the event that wet conditions and/or seepage are encountered, sumps and pumps should be adequate to maintain stable conditions during foundation construction. The foundation excavations should not be used as a detention basin or sump. During construction, surface runoff should be prevented from entering the excavations by creating soil berms or diversion swales along the perimeter if the excavation is expected to be open for a long period of time. Where ponding does occur, the water should be pumped immediately and grades should then be established to prevent further ponding.

Based on groundwater encountered at depths ranging from 15.0 to 25.0 feet (Elev. 275.0 to 299.5 feet, NAVD88) below the existing ground surface and RMFs at approximate depths ranging from 10 to 20 feet below the existing ground surface (Elev. 290.0 to 296.0 feet, NAVD88), it is our opinion that foundation drains are not necessary for the proposed renovation foundations.

5.5. EARTHWORK

Prior to placing any new fill, and before the construction of the proposed foundations, any construction debris, vegetation, existing utilities, and associated topsoil must be removed from within the areas of proposed construction. These materials can remain in proposed landscaped areas provided that future plans do not include building in those areas.

Exposed subgrades should be thoroughly evaluated by a representative of the Geotechnical Engineer in an attempt to identify unstable (soft, yielding, etc.) surface areas. Any unstable area found should be stabilized by excavating and replacing those soils with suitable soil (adequately compacted, see below), by lowering the moisture content of the subgrade soils and compacting them, or by other methods (placing a geotextile and stone layer, etc.). To reduce the potential for damage to the subgrade, we recommend that construction traffic over the subgrade be kept to a minimum. Also, concrete for foundations should be placed as soon as possible following the subgrade preparation.

Our experience indicates that the on-site soils of Strata F and A through C can be reused for the construction, provided all organics and debris larger than 3 inches in its greatest dimension be removed prior to reuse.

Strata F, A, and C soils were observed to contain a significant amount of fine-grained material (silts/clays).

These types of soils are sensitive to moisture and may therefore require wetting or drying prior to compaction.

Drying “wet” soil is difficult during wet periods and during lower temperatures. Therefore, provisions for importing structural fill should be included in the contract documents. If necessary, granular fill should consist of well-graded material with a maximum particle size less than 3 inches, not more than 20 percent passing the No. 200 sieve and have a plasticity index (PI) not greater than 8 percent.

Fills should be placed in layers not exceeding 10 to 12 inches loose measure. This criterion might be adjusted by the geotechnical engineer in the field depending on the conditions present at the time of construction, on the compaction equipment used, and on the fill materials selected. Fills for support of foundations/floor slabs/pavements should be compacted to at least 98 percent of the laboratory determined dry density, ASTM D-698, when small, hand-operated compaction equipment is used, and to at least 95 percent of the laboratory determined maximum dry density, ASTM D-1557, when self-propelled, heavy-duty construction equipment is used. Fills should extend a minimum of 5 feet beyond the exterior edge of a loaded area and have side slopes not steeper than 2 horizontal to 1 vertical.

Specifications should indicate that the percentage of maximum dry density attained in the field is not the only criteria to be used for assessing fill compaction. Observation of the behavior of the fill under the loads of construction equipment should also be used. If the test results indicate that the percentage of compaction is being achieved, but the soil mass is moving under the equipment, placement of additional fill should not be continued until the movement is stabilized. Otherwise, settlement of the fill may occur.

5.6. EXISTING AND PROPOSED UTILITIES

Existing utilities noted in the field included (but may not be limited to): water, electric, sewer and unknown lines located around the perimeter of the existing building and floor drains located underneath the Central Annex slab on grade. We recommend that load bearing elements of the proposed construction not bear over existing utilities in order to reduce the potential for damage and utilities be relocated outside of the footprints of the proposed structure. Utilities were noted to be run parallel through the fire lanes adjacent to the north and south Annexes. Utilities should be protected throughout the construction duration.

6. LIMITATIONS

This work has been done in accordance with our authorized scope of work and in accordance with generally accepted professional practice in the fields of geotechnical and foundation engineering. This warranty is in lieu of all other warranties either expressed or implied. Our conclusions and recommendations are based on the data revealed by this exploration. We are not responsible for any conclusions or opinions drawn from the data included herein, other than those specifically stated, nor are the recommendations presented in this report intended for direct use as construction specifications. This report is intended for use with regard to the specific project described herein; any changes in loads, structures, or locations should be brought to our attention so that we may determine how they may affect our conclusions. An attempt has been made to provide for normal contingencies but the possibility remains that unexpected conditions may be encountered during construction. If this should occur, or if additional or contradictory data are revealed in the future, we should be notified so that modifications to this report can be made, if necessary. If we do not review relevant construction documents and witness the relevant construction operations, then we cannot be responsible for any problems that may result from misinterpretation or misunderstanding of this report or failure to comply with our recommendations.

APPENDICES

APPENDIX A – Location Sketches

SITE LOCATION SKETCH

NAME OF JOB

Pennoni Associates, Inc.

8890 McGaw Road, Suite 100

Columbia, MD 21045

ALL DOCUMENTS PREPARED BY PENNONI

ASSOCIATES ARE INSTRUMENTS OF SERVICE IN

RESPECT OF THE PROJECT. THEY ARE NOT INTENDED

OR REPRESENTED TO BE SUITABLE FOR REUSE BY

OWNER OR OTHERS ON EXTENSIONS OF THE

PROJECT OR ON ANY OTHER PROJECT. ANY REUSE

WITHOUT WRITTEN VERIFICATION OR ADAPTATION

BY PENNONI ASSOCIATES FOR THE SPECIFIC PURPOSE

INTENDED WILL BE AT OWNERS SOLE RISK AND

WITHOUT LIABILITY OR LEGAL EXPOSURE TO

PENNONI ASSOCIATES; AND OWNER SHALL

INDEMNIFY AND HOLD HARMLESS PENNONI

ASSOCIATES FROM ALL CLAIMS, DAMAGES, LOSSES,

AND EXPENSES ARISING OUT OF OR RESULTING

THEREFROM.

DRAWN BY:

ARS

SCALE:

As Shown

DATE:

1 3/2022

CHECKED BY:

JSD

FIGURE No.

PROJECT No.

AEWLA22050

SK-1

AFRH Sheridan Building Renovations – Washington, DC

Site Location Sketch adapted from Google Earth Image dated October 16, 2019.

N orth C apitol S t N

W

10/14/2022

Project site outlined in red

N O

R

TH

BORING LOCATION SKETCH

NAME OF JOB

Pennoni Associates, Inc.

8890 McGaw Road, Suite 100

Columbia, MD 21045

ALL DOCUMENTS PREPARED BY PENNONI

ASSOCIATES ARE INSTRUMENTS OF SERVICE IN

RESPECT OF THE PROJECT. THEY ARE NOT INTENDED

OR REPRESENTED TO BE SUITABLE FOR REUSE BY

OWNER OR OTHERS ON EXTENSIONS OF THE

PROJECT OR ON ANY OTHER PROJECT. ANY REUSE

WITHOUT WRITTEN VERIFICATION OR ADAPTATION

BY PENNONI ASSOCIATES FOR THE SPECIFIC PURPOSE

INTENDED WILL BE AT OWNERS SOLE RISK AND

WITHOUT LIABILITY OR LEGAL EXPOSURE TO

PENNONI ASSOCIATES; AND OWNER SHALL

INDEMNIFY AND HOLD HARMLESS PENNONI

ASSOCIATES FROM ALL CLAIMS, DAMAGES, LOSSES,

AND EXPENSES ARISING OUT OF OR RESULTING

THEREFROM.

DRAWN BY:

ARS

SCALE:

NTS

DATE:

10/14/2022

CHECKED BY:

JSD

FIGURE No.

PROJECT No.

AEWLA22050

SK-2

AFRH Sheridan Building Renovations – Washington, DC

Boring Location Sketch adapted from an undated Topography Survey Plan titled “AFRH – Topography Survey,” prepared by Pennoni Associates Inc.

299.5300.1

300.2 300.2

300.3300.3

300.6 300.6

300.8300.7

300.8 300.7

301.0301.0

301.3 301.1

301.4301.4

301.6 301.6

304.4301.7

301.9

301.6301.2

301.0

301.0

300.6

300.4300.7

301.2

301.4 300.9 300.6 300.1299.9

301.9 301.4 301.1

298.7 299.3

300.2

298.9299.1 301.3

301.6

301.7299.6

298.9

302.3

302.6

303.9

304.6

308.3

306.1

309.9311.5 316.5

310.4

307.0 306.6 307.0

300.3

300.7

302.0

303.8

302.2 301.2 301.2302.6

303.1

305.3

306.3

303.8 304.8

305.1 304.5

313.1 309.6

317.1

317.0

317.1

317.0

317.4

317.9317.2 317.0

316.8 316.8

320.3

319.2

318.4

316.5

316.5

317.4

316.8

317.2

317.4

316.7

316.6

316.3316.4

316.5

316.8

316.7

317.1 316.8

315.9

316.2315.8

316.4 316.5

GAS

FILLED W/DEBRIS

BOTT=301.44' UNABLE TO OPEN

"R

PC

RIM=300.81

INV=296.71

RIM=300.77

IN=295.22

OUT-294.97

RIM=300.97

OUT=295.27

RIM=300.81

IN=296.23

OUT=296.13

RIM=300.17

OUT=298.27

RIM=299.92

IN(8")=296.42

IN(INLET)=297.92

OUT=296.32

"R

CP

"R

C P

6" M

ET

AL

24"R

RIM=301

IN(6"MET

IN(18"RC

IN(15"RC

OUT=29

RIM=300.

IN(12"RC

IN(15")=2

IN(18")=2

OUT=292

RIM=299

IN=292.1

OUT=29

8"RPC

8" R

C P

"R

CP

15"RCP

"R

CP

8"

RPC

230430630831

231431

304306

E E

INLET

UNABLE TO OPEN

GRATE=315.90'

OUT=311.20

GRATE=315.75

IN=310.75

IN=310.55

IN=310.15

OUT=310.05

RIM=315.93

IN=312.43

OUT=311.60

18" P

8"RCP

24"P

8"PVC

12"R C

P 15"R

C P

15.54 311.94 =311.94 5")=311.74

GRATE=315.14

OUT=312.44

8"RCP FULL OF DEBRIS

RIM=316.75

IN=312.45

OUT=312.08

GRATE=316.20

OUT=314.20

6"PVC

W

RIM=317.17

IN=311.97

OUT=311.82

C O

N C

W

ALK

C O

N C

W

ALK

C O

N C

W

AL

K

PAVERS

CO

NC

CONC WALK

BUS

STOP

BUS

STOP

C O

N C

W

AL

K

C .C

G

C .C

G

C .C

G

C .C

G

MB

N O

R

TH

B-1

B-2

B-4

B-5B-6

B-7

B-8

B-3*

= Approximate Boring Location

*Boring B-3 not performed due to utility conflict

= Approximate Location of Proposed Boring Not Performed

APPENDIX B – Boring Logs

P

F

6" CONCRETE

4" Graded Aggregate Base Coarse FILL: Brown to black clay, little fine to medium to coarse sand, trace fine gravel

FILL: Brown to black clay, little fine to medium to coarse sand, trace fine gravel, trace concrete debris Borehole terminated at 6.5 feet.

2-3-4-6

6-5-5-5

5-5-50/4"

S-1

S-2

S-3 Spoon refusal at 6.5 ft

Apparent Concrete Obstruction

303.5

297.5

0.5 0.8

5.0

6.5

DRILLING METHOD Tripod

DRILLING CONTRACTOR DMY Engineering Consultants

DATE STARTED 9/19/22 COMPLETED 9/19/22

WATER ENCOUNTERED:

CHECKED BY S. DonahueLOGGED BY A. Spencer

DRILLER / HELPER David Vazquez / Daniel Pao

GROUND ELEVATION 304.0' NAVD88

DURING DRILLING Not Encountered

AT END OF DRILLING Not Encountered

AFTER DRILLING Not Encountered

LATITUDE 38.940976

LONGITUDE -77.009656

NOTES:

Elevations estimated from an undated Topographic Survey titled "AFRH," prepared by Pennoni Associates Inc.

TEST BORING LOG

TEST BORING B-1

S T

R A

T A

D E

P T

H (f t)

DESCRIPTIONB

LO

W C

O U

N T

S

R E

C O

V E

R Y in

S A

M P

LE

T

Y P

E N

U M

B E

R

REMARKS

Elev.

G R

A P

H

IC

LO

G

Depth

CLIENT AE-Works

PROJECT NUMBER AEWLA22050

PROJECT NAME AFRH Sheridan Building Renovations

PROJECT LOCATION 140 Rock Creek Church Road NW, Washington, DC.

A

C

6" CONCRETE

4" Graded Aggregate Base Coarse FILL: Tan fine to medium sand, little silt FILL: Brown clay and fine to medium to coarse sand, little fine gravel Brown to tan CLAY, some fine to medium to coarse sand, trace fine gravel Brown to tan to gray silty CLAY

Gray to orange silty CLAY

Gray to black fine to medium SAND and SILT

Borehole terminated at 25.0 feet.

10-15-21-23

15-10-6-6

6-5-4-4

6-7-7-12

9-10-12-15

5-5-5-6

6-8-8-10

13-12-14-16

S-1

S-2

S-3

S-4

S-5

S-6

S-7

S-8

Saturated

303.5

299.0

286.0

279.0

0.5 0.8

3.0

5.0

7.0

13.0

18.0

25.0

DRILLING METHOD Tripod

DRILLING CONTRACTOR DMY Engineering Consultants

DATE STARTED 9/20/22 COMPLETED 9/20/22

WATER ENCOUNTERED:

CHECKED BY S. DonahueLOGGED BY A. Spencer

DRILLER / HELPER David Vazquez / Hernan Guzman

GROUND ELEVATION 304.0' NAVD88

DURING DRILLING 14.0' / Elev 290.0'

AT END OF DRILLING

AFTER DRILLING 13.5' / Elev 290.5'

LATITUDE 38.940901

LONGITUDE -77.009745

NOTES:

Elevations estimated from an undated Topographic Survey titled "AFRH," prepared by Pennoni Associates Inc.

TEST BORING LOG

TEST BORING B-2

S T

R A

T A

D E

P T

H (f t)

DESCRIPTIONB

LO

W C

O U

N T

S

R E

C O

V E

R Y in

S A

M P

LE

T

Y P

E N

U M

B E

R

REMARKS

Elev.

G R

A P

H

IC

LO

G

Depth

CLIENT AE-Works

PROJECT NUMBER AEWLA22050

A

C

A

B

A

7" ASPHALT

FILL: Brown to tan medium fine to coarse sand, some fine to coarse gravel, little silt FILL: Brown clay, some medium to fine to coarse sand, little fine gravel FILL: Brown clay and fine to medium to coarse sand, trace fine gravel

Tan to orange to gray CLAY, little fine to medium sand

Black clayey SILT, little fine to medium sand

Gray CLAY

Gray to orange fine to medium to coarse SAND and CLAY, trace fine gravel

Gray to maroon CLAY

Borehole terminated at 35.0 feet.

7-5

2-3-2-2

1-2-2-2

2-1-2-2

WOH-1-1-1

2-1-2-3

2-1-2-3

2-3-4-7

4-7-8-18

3-6-8-13

S-1

S-2

S-3

S-4

S-5

S-6

S-7

S-8

S-9

S-10

Moist

Mottling

Moist

299.4

287.0

282.0

277.0

270.5

267.0

265.0

0.6

2.0

4.0

13.0

18.0

23.0

29.5

33.0

35.0

DRILLING METHOD 3.25 Hollow Stem Auger

DRILLING CONTRACTOR DMY Engineering Consultants

DATE STARTED 9/20/22 COMPLETED 9/20/22

WATER ENCOUNTERED:

CHECKED BY S. DonahueLOGGED BY A. Spencer

DRILLER / HELPER Michael Beccerra / Lance James

GROUND ELEVATION 300.0' NAVD88

DURING DRILLING 25.0' / Elev 275.0'

AT END OF DRILLING

AFTER DRILLING 25.0' / Elev 275.0'

LATITUDE 38.941301

LONGITUDE -77.009499

NOTES:

Elevations estimated from an undated Topographic Survey titled "AFRH," prepared by Pennoni Associates Inc.

TEST BORING LOG

TEST BORING B-4

S T

R A

T A

D E

P T

H (f t)

DESCRIPTIONB

LO

W C

O U

N T

S

R E

C O

V E

R Y in

S A

M P

LE

T

Y P

E N

U M

B E

R

REMARKS

Elev.

G R

A P

H

IC

LO

G

Depth

CLIENT AE-Works

PROJECT NUMBER AEWLA22050

A

C

B

A

3" ASPHALT

16" Graded Aggregate Base Coarse FILL: Brown clay, some medium to fine to coarse sand, trace fine gravel FILL: Brown clay and medium to fine to coarse sand, little fine gravel

Brown to tan silty CLAY, little fine to medium sand

Brown to orange to gray CLAY, some fine to medium sand

Brown to orange to gray silty CLAY

Black SILT, some fine sand

Gray medium to fine to coarse SAND and CLAY

Gray to maroon medium to fine to coarse SAND and CLAY

Gray to orange silty CLAY, little to some fine to medium sand Borehole terminated at 35.0 feet.

4-4-2-2

5-9-10-6

2-2-3-3

3-3-4-4

2-2-3-3

1-1-1-1

1-3-5-8

4-12-13-20

10-8-9-13

S-2

S-3

S-4

S-5

S-6

S-7

S-8

S-9

S-10

Auger through base coarse

Moist Mottling

Saturated

Wet on spoon

301.3

295.0

282.5

278.5

268.5

266.5

0.3

2.0

4.0

6.5

8.0

13.0

19.0

23.0

28.0

33.0

35.0

DRILLING METHOD 3.25 Hollow Stem Auger

DRILLING CONTRACTOR DMY Engineering Consultants

DATE STARTED 9/20/22 COMPLETED 9/20/22

WATER ENCOUNTERED:

CHECKED BY S. DonahueLOGGED BY A. Spencer

DRILLER / HELPER Michael Beccerra / Lance James

GROUND ELEVATION 301.5' NAVD88

DURING DRILLING 18.0' / Elev 283.5'

AT END OF DRILLING

AFTER DRILLING 15.0' / Elev 286.5'

LATITUDE 38.94057

LONGITUDE -77.009597

NOTES:

Elevations estimated from an undated Topographic Survey titled "AFRH," prepared by Pennoni Associates Inc.

TEST BORING LOG

TEST BORING B-5

S T

R A

T A

D E

P T

H (f t)

DESCRIPTIONB

LO

W C

O U

N T

S

R E

C O

V E

R Y in

S A

M P

LE

T

Y P

E N

U M

B E

R

REMARKS

Elev.

G R

A P

H

IC

LO

G

Depth

CLIENT AE-Works

PROJECT NUMBER AEWLA22050

A

B

A

3" ASPHALT

16.5" Graded Aggregate Base Coarse FILL: Tan to gray to maroon silty clay, little fine to medium sand FILL: Tan to gray to maroon silty clay

Gray silty CLAY

Gray fine to medium SAND, some silt

Gray CLAY

Maroon CLAY

Maroon to gray CLAY, little fine to medium sand

Borehole terminated at 35.0 feet.

2-2-2-3

1-2-1-2

2-2-2-3

1-2-2-3

1-2-2-4

1-1-2-1

3-5-5-7

8-10-12-18

3-5-9-13

S-2

S-3

S-4

S-5

S-6

S-7

S-8

S-9

S-10

Auger through subbase

Obstruction encountered at 3 feet below existing grade.

Boring offset approximately 1 feet north

Moist

Saturated

300.8

295.0

283.0

278.0

266.0

0.3

2.0

4.0

6.0

18.0

23.0

29.0

33.0

35.0

DRILLING METHOD 3.25 Hollow Stem Auger

DRILLING CONTRACTOR DMY Engineering Consultants

DATE STARTED 9/19/22 COMPLETED 9/19/22

WATER ENCOUNTERED:

CHECKED BY S. DonahueLOGGED BY A. Spencer

DRILLER / HELPER Michael Beccerra / Adrian Quijada

GROUND ELEVATION 301.0' NAVD88

DURING DRILLING 20.0' / Elev 281.0'

AT END OF DRILLING

AFTER DRILLING 20.5' / Elev 280.5'

LATITUDE 38.940579

LONGITUDE -77.009842

NOTES:

Elevations estimated from an undated Topographic Survey titled "AFRH," prepared by Pennoni Associates Inc.

TEST BORING LOG

TEST BORING B-6

S T

R A

T A

D E

P T

H (f t)

DESCRIPTIONB

LO

W C

O U

N T

S

R E

C O

V E

R Y in

S A

M P

LE

T

Y P

E N

U M

B E

R

REMARKS

Elev.

G R

A P

H

IC

LO

G

Depth

CLIENT AE-Works

PROJECT NUMBER AEWLA22050

B

A

9" CONCRETE

3" Graded Aggregate Base Coarse FILL: Brown CLAY, some medium to fine to coarse sand, trace fine gravel

Tan to brown medium to fine to coarse SAND, little fine gravel, trace silt Tan to brown fine to coarse GRAVEL, some medium to coarse to fine sand, trace silt

Tan to brown medium to fine to coarse SAND, little fine gravel, trace silt

Gray to orange CLAY

Borehole terminated at 20.0 feet.

3-9-10-8

6-7-6-8

3-4-4-7

5-6-5-6

10-22-22-17

5-5-6-6

2-1-3-2

S-1

S-2

S-3

S-4

S-5

S-6

S-7

Moist

Iron staining

315.8

309.5

298.5

296.5

0.8 1.0

7.0

9.0

13.0

18.0

20.0

DRILLING METHOD 3.25 Hollow Stem Auger

DRILLING CONTRACTOR DMY Engineering Consultants

DATE STARTED 9/21/22 COMPLETED 9/21/22

WATER ENCOUNTERED:

CHECKED BY S. DonahueLOGGED BY A. Spencer

DRILLER / HELPER Michael Beccerra / Lance James

GROUND ELEVATION 316.5' NAVD88

DURING DRILLING Not Encountered

AT END OF DRILLING Not Encountered

AFTER DRILLING Not Encountered

LATITUDE 38.940875

LONGITUDE -77.010245

NOTES:

Elevations estimated from an undated Topographic Survey titled "AFRH," prepared by Pennoni Associates Inc.

TEST BORING LOG

TEST BORING B-7

S T

R A

T A

D E

P T

H (f t)

DESCRIPTIONB

LO

W C

O U

N T

S

R E

C O

V E

R Y in

S A

M P

LE

T

Y P

E N

U M

B E

R

REMARKS

Elev.

G R

A P

H

IC

LO

G

Depth

CLIENT AE-Works

PROJECT NUMBER AEWLA22050

B

A

9.5" CONCRETE

3" Graded Aggregate Base Coarse FILL: Brown to tan clay, some medium to fine to coarse sand FILL: Brown to tan clay, some medium to fine to coarse sand, trace fine gravel

Brown to tan medium to fine to coarse SAND and CLAY, trace fine gravel Brown to tan medium to fine to coarse SAND, some clay, trace fine gravel

Brown to orange medium to fine to coarse SAND, little fine to coarse gravel, little silt

Orange to gray CLAY Borehole terminated at 20.0 feet.

2-3-4-6

5-6-8-9

5-5-7-11

4-5-5-8

5-5-6-8

8-16-13-6

4-4-4-7

S-1

S-2

S-3

S-4

S-5

S-6

S-7

Moist

Moist

Saturated

315.8

309.5

297.0 296.5

0.8 1.0

3.0

7.0

9.0

13.0

19.5 20.0

DRILLING METHOD 3.25 Hollow Stem Auger

DRILLING CONTRACTOR DMY Engineering Consultants

DATE STARTED 9/21/22 COMPLETED 9/21/22

WATER ENCOUNTERED:

CHECKED BY S. DonahueLOGGED BY A. Spencer

DRILLER / HELPER David Vazquez / Hernan Guzman

GROUND ELEVATION 316.5' NAVD88

DURING DRILLING 18.0' / Elev 298.5'

AT END OF DRILLING

AFTER DRILLING 17.0' / Elev 299.5'

LATITUDE 38.941049

LONGITUDE -77.010222

NOTES:

Elevations estimated from an undated Topographic Survey titled "AFRH," prepared by Pennoni Associates Inc.

TEST BORING LOG

TEST BORING B-8

S T

R A

T A

D E

P T

H (f t)

DESCRIPTIONB

LO

W C

O U

N T

S

R E

C O

V E

R Y in

S A

M P

LE

T

Y P

E N

U M

B E

R

REMARKS

Elev.

G R

A P

H

IC

LO

G

Depth

CLIENT AE-Works

PROJECT NUMBER AEWLA22050

APPENDIX C – Geotechnical Laboratory Test Results

SUMMARY OF LABORATORY DATA

B-2 S-3 5-7 CL 1 24 75 38 21 17 0.03 21.5

B-2 S-7 18-20 ML 0 64 36 NV NP NP NV 38.0

B-4 S-5 8-10 CL 5 36 59 43 17 26 0.18 21.6

B-4 S-9 28-30 8 50 42 18.1

B-5 S-5 8-10 CH 0 28 72 65 24 41 0.27 34.9

B-5 S-9 28-30 ML 0 62 38 42 27 15 0.31 31.7

B-6 S-4 7-9 0 1 99 55.1

B-6 S-7 18-20 0 78 22 38.0

B-7 S-5 9-11 58 35 7 3.2

B-8 S-4 7-9 6 67 28 14.7

DRAWN BY: DATE: PROJECT: JOB No.:

AFRH Sheridan Building Renovations

CHECKED BY: DATE: LOCATION: TABLE No.:

Washington, DC

PENNONI ASSOCIATES INC.

B O

R

IN

G N

U M

B E

R

10/5/2022

M O

IS

T

U R

E C

O N

T E

T w

S A

M P

L E

N U

M B

E R

D E

P T

H ft

S O

IL

C

L A

S S

IF

IC

A T

IO

N

GRAIN SIZE

DISTRIBUTION

PLASTICITY

G R

A V

E L

L

IQ

U

ID

IT

Y

I N

D E

X

I

L

S A

D

S

IL

T /C

L A

Y

L

IQ

U

ID

L

IM

IT

w l

P L

A S

T

IC

L

IM

IT

w p

P L

A S

T

IC

IT

Y

I N

D E

X

I

P

JEK

p H i n

H p H i n

C a C l 2 pH

O R

G A

N

IC

C O

N T

E N

T

L-1

V O

ID

R

A T

IO

e)

D E

G R

E E

O F

S A

T U

R A

T

IO

N

VOLUMETRIC

R E

S

IS

T

IV

IT

Y o h m -c m a t

T C

S P

E C

IF

IC

G R

A V

IT

Y

G

A S

S U

M E

D

D R

Y U

N

IT

W E

IG

H

T p cf

M O

IS

T

U N

IT

W

E

IG

H T p cf

AEWLA22050

ARS 10/6/2022

EC

Coarse Fine Coarse Medium Fine Silt Clay

∗ 0.0 1.3 2.0 2.3 19.4 21.5

● 0.0 0.0 0.1 2.8 61.4 38.0

▲ 0.0 4.9 5.3 13.1 17.6 21.6

□ 0.0 7.8 5.5 3.7 40.6 18.1

◇ 0.0 0.0 0.1 13.9 14.4 34.9

◆ 0.0 0.0 8.3 38.1 15.1 31.7

▓ 0.0 0.0 0.0 0.1 0.4 55.1

○ 0.0 0.0 0.0 5.1 72.7 38.0

△ 16.5 41.3 9.9 15.6 9.4 3.2

SYMBOL SOURCE SAMPLE DEPTH (ft)

∗ B-2 S-3 5-7

● B-2 S-7 18-20

▲ B-4 S-5 8-10

□ B-4 S-9 28-30

◇ B-5 S-5 8-10

◆ B-5 S-9 28-30

▓ B-6 S-4 7-9

○ B-6 S-7 18-20

△ B-7 S-5 9-11

Client: AE Works

Project:

Location:

Lab No. 10-

Figure

35.8

% Gravel % Sand % Fines Moisture (%)

75.0

F/M/C SAND, AND SILT/CLAY, TRACE F GRAVEL

59.1

42.4

71.5

38.5

99.5

22.2

7.3

MATERIAL DESCRIPTION

CLAY, SOME F/M/C SAND, TRACE F GRAVEL

F/M SAND, AND SILT

CLAY, AND F/M/C SAND, TRACE F GRAVEL

PENNONI ASSOCIATES INC. Washington, DC

S-1

CLAY, SOME F/M SAND

M/F/C SAND, AND SILT

SILT/CLAY

F/M SAND, SOME SILT/CLAY

F/C GRAVEL, SOME M/C/F SAND, TRACE SILT/CLAY

AFRH Sheridan Building Renovations

3/4" 3/8" #4 #10 #40 #50 #100 #200

0.010.101.0010.00100.00

P E

R C

E N

T F

IN

E

R

GRAIN SIZE - mm

Particle Size Distribution Report

Coarse Fine Coarse Medium Fine Silt Clay

∗ 0.0 5.8 3.4 15.1 48.2 14.7

SYMBOL SOURCE SAMPLE DEPTH (ft)

∗ B-8 S-4 7-9

Client: AE Works

Project:

Location:

Lab No. 10-

Figure

PENNONI ASSOCIATES INC.

AFRH Sheridan Building Renovations

Washington, DC

S-2

MATERIAL DESCRIPTION

F/M/C SAND, SOME SILT/CLAY, TRACE F GRAVEL

% Gravel % Sand % Fines Moisture (%)

27.5

3/4" 3/8" #4 #10 #40 #50 #100 #200

0.010.101.0010.00100.00

P E

R C

E N

T F

IN

E

R

GRAIN SIZE - mm

Particle Size Distribution Report

△ B-2 S-3 5-7 21.5 21 38 17 CL

● B-2 S-7 18-20 38.0 NP NV NP ML

◆ B-4 S-5 8-10 21.6 17 43 26 CL

□ B-5 S-5 8-10 34.9 24 65 41 CH

∗ B-5 S-9 28-30 31.7 27 42 15 ML

Project No.: AEWLA22050 Client:

Project:

Notes: Plastic Limit Procedure 1

Manual liquid limit device and plastic grooving tool

Figure A-1

PENNONI ASSOCIATES INC.

Bethlehem, PA

AFRH Sheridan Building Renovations

AE Works

ASTM D4318 - Liquid Limit, Plastic Limit, and Plasticity Index of Soils

Symbol Depth Natural Water

Content (%)

Plastic Limit

Liquid Limit

Source Sample No.

Plasticity

Index

USCS

(fines only)

0 20 40 60 80 100

P

LA

S T

IC

IT

Y I

N D

E X

LIQUID LIMIT

CL-ML ML or OL

MH or OH

PSS Project No.: 22092909

Certificate of Analysis

Sheridan Building

6630 Baltimore National Pike Baltimore, MD 21228

410-747-8770 800-932-9047 www.phaseonline.com

Project Name:

Ayche Damtew DMY Engineering 4170 Lafayette Center Dr., Ste. 500 Chantilly, VA 20151

Reference: PSS Project No: 22092909 Project Name: Sheridan Building Project Location: NW District of Columbia Project ID.: 01.5864.01

Dear Ayche Damtew:

This report includes the analytical results from the analyses performed on the samples received under the project name referenced above…