Geotechnical_Report.pdf

GEOTECHNICAL SUBSURFACE INVESTIGATION REPORT

Large Water Valve and Vault Replacement Montgomery County, Maryland WSSC Project No. BT7370A22

PREPARED FOR:

The Wilson T. Ballard Company 17 Gwynns Mill Court

Owings Mills, Maryland 21117

PREPARED BY:

AB CONSULTANTS, INC.

9450 ANNAPOLIS ROAD

LANHAM, MARYLAND 20706

November 20, 2023

Ph: (301) 306-3091;

Fax: (301) 306-3092 www.abconsultantsinc.com Engineers Planners Surveyors Support Services

Baltimore Office: 7020 Tudsbury Road, Baltimore, Maryland 21244, Ph: (443) 729-2650

AB CONSULTANTS, INC.

9450 Annapolis Road Lanham, Maryland 20706

November 20, 2023

Attn: Mr. Shawn Burnett, PE, PTOE The Wilson T. Ballard Company, 17 Gwynns Mill Court Owings Mills, Maryland 21117

REF: Report of Subsurface Investigation and Studies for Large Water Valve and Vault Replacement Montgomery County, Maryland WSSC Project No: BT 7370A22 AB Job No. 2020534-12

Dear Mr. Burnett:

AB Consultants, Inc. (ABC) is pleased to submit this soil report containing the results of the geotechnical investigation for the above-referenced project. To obtain information of the subsurface conditions, one (1) 15-foot deep soil boring was drilled, and one (1) pavement core was performed at the project site. The purpose of this study was to explore the subsurface conditions for the proposed replacement of a large water valve and vault located in Silver Spring, Maryland. The following report sections discuss the results of field and laboratory studies, design and construction methods for the proposed structure.

All samples obtained from soil test borings will be retained in our laboratory for a period of thirty (30) days from the date of this report. They will be available for inspection during this period. After that time, the samples will be discarded.

It has been a pleasure serving you on this project. If you have any questions regarding this report, or if we can be of further service in any way, please contact us.

Very truly yours, recommendations AB Consultants, Inc.

Fu Guo, P.E. Andinet Tolla, P.E.

Project Engineer Project Manager

Large Water Valve and Vault Replacements Geotechnical Report WSSC Contract No #: BT7370A22 November 20, 2023 AB Job No.: 2020534.12 Page 1

AB CONSULTANTS, INC.

TABLE OF CONTENTS

1.0 INTRODUCTION

1.1 GENERAL

1.2 SCOPE OF WORK

1.3 SITE LOCATION

2.0 FIELD ACTIVITIES AND SUBSURFACE EXPLORATION

2.1 PAVEMENT CORE

2.2 SOIL BORING

2.3 SUBSURFACE INVESTIGATION

3.0 LABORATORY TESTING PROGRAM

3.1 LABORATORY TESTING PROGRAM

3.2 LABORATORY RESULTS

4.0 GENERAL SITE AND SUBSURFACE CONDITIONS

4.1 SITE CONDITION

4.2 SITE GEOLOGY

4.3 SUBSURFACE SOIL CONDITION

4.4 GROUNDWATER OBSERVATION

5.0 ANALYSIS AND RECOMMENDATIONS

5.1 THRUST RESTRAINT

5.2 METER VAULT FOUNDATION

5.3 BELOW GRADE WALL

5.4 EXCAVATION

5.5 STRUCTURAL FILL

5.6 CONSTRUCTION CONSIDERATIONS

6.0 GENERAL COMMENTS

APPENDICES A. General Notes B. Vicinity Map C. Boring Plan D. Boring Log and Lab Test Results E. Pavement Core Summary

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1.0 INTRODUCTION

1.1 General

This report presents the subsurface exploration findings, laboratory test results and geotechnical recommendations for the proposed replacement of a large water valve and vault replacement located in Silver Spring, Maryland. Based on the information provided, approximately 48 linear feet of 72” and 81 linear feet of 30” Prestressed

Concrete Cylinder Pipe (PCCP) watermain will be replaced and relocated with 72” and

30” respectively Ductile Iron Pipe (DIP) waterline. In addition, water valve and vault is proposed. This subsurface study was conducted for The Wilson T Ballard Company and has been performed in general accordance with letter proposal dated September 19, 2022.

1.2 Scope of Work

The investigation of existing subsurface soil conditions at the sites consisted of the following:

Evaluating existing pavement sections by coring.

Planning and executing subsurface exploration programs to evaluate soil and ground conditions for the meter vault replacement.

Performing soil laboratory tests on soil samples obtained from the boring.

Providing a geotechnical report that includes field findings, laboratory results and geotechnical recommendations.

1.3 Site Location

The field study was performed in the park area next to the Warwick Apartments building, located at 1131 W University Boulevard, Silver Spring, Maryland.

2.0 FIELD ACTIVITIES AND SUBSURFACE EXPLORATION

2.1 Pavement Core

The purpose of pavement coring was to determine the existing pavement thickness and subgrade materials encountered, and to provide a summary of field results for the pavement study. A portable core drill machine with a 4-inch diameter diamond core drill bit was utilized to obtain the sample. One (1) pavement core was retrieved from the Sligo Creek Trail on November 07, 2023. The results of the field findings are summarized in Appendix E.

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2.2 Soil Boring

To obtain information of the subsurface conditions, one (1) soil boring was drilled at the project site. The boring was drilled to a depth of 15 feet below existing grade on

November 07, 2023. The soil boring was staked out in the field by ABC; in addition, field drilling operations were managed and supervised by ABC. A site vicinity map and boring plan are included in Appendix B and C, respectively.

2.3 Subsurface Investigation

The boring for this project was drilled using Truck-mounted drill rig, CME 45B.

Test boring was advanced using hollow-stem augers and soil samples were obtained using the Standard Penetration Test (SPT) procedure in accordance with ASTM D1586.

SPT samples were obtained from the boring at depth intervals of 2.5 feet in the top ten feet, and at 5-foot intervals, thereafter. A representative portion of each split spoon sample was placed in a glass jar and transported to our laboratory. In addition, a bulk sample was obtained.

In the split-barrel sampling procedure, a 2-inch O.D. split-barrel sampling spoon is driven into the ground with a 140-pound hammer, free falling a distance of 30 inches.

The blows required to advance the sampling spoon to a specified distance are reported as the penetration resistance values. The values are shown on the boring log at the depths of their occurrence. The N-value is the sum of standard penetration resistance values that advanced through the last 12 inches of sampling. The N-value is an indication of the relative density of in-place granular soils and, to a lesser degree of accuracy, the consistency of cohesive soils.

Groundwater levels were monitored in the boring. Samples obtained from the boring were inspected by a geotechnical engineer and the field log was edited accordingly. The final log indicating the encountered subsurface condition is included in

Appendix D.

3.0 LABORATORY TESTING PROGRAM

3.1 Laboratory Testing Program

Laboratory tests were performed on selected representative samples. Natural moisture contents were performed on all soil samples, and the results are included in the

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boring log. Atterberg limit was performed on bulk sample and sieve analysis tests were conducted on selected samples; in addition, a modified proctor test was performed on the bulk sample. Gradation curves and proctor result are presented in Appendix E.

3.2 Laboratory Results

Results of the modified proctor laboratory test is summarized in the following table. Other pertinent soil data is presented in the boring log and Appendix D.

RESULTS SUMMARY OF MODIFIED PROCTOR TEST

Boring No.

Sample Depth

(ft)

Atterberg Limits Passing

#200 Sieve (%)

Modified Proctor Test

Classification

LL PL PI

Maximum Dry Density

(pcf)

Optimum Moisture

Content (%) SB-01 1 to 6 35 19 16 41.6 128 9.6 SC / A-2-6

4.0 GENERAL SITE AND SUBSURFACE CONDITIONS

4.1 Site Condition

The field study was located in the park area next to the Warwick Apartments building located at 1131 University Boulevard, Silver Spring, Maryland. Boring SB-01 was drilled in the vegetation area between the Sligo Creek Trail and the parking lot of

1131 university Boulevard and north of W University Boulevard. Pavement Core PC-01 was performed on the Sligo Creek Trail. High rise Apartment building is found east of the study site.

4.2 Site Geology

According to the Maryland Geological Map published by The Maryland Geologic

Survey (1968), the subject project site appears to be located within the Wissahickon

Formation; Lower Pelitic Schist (Formerly mapped as oligoclase facies of Wissahickon

Formation.). This formation consists of medium- to coarse-grained biotite-oligoclase-muscovite-quartz schist with garnet, staurolite, and kyanite; fine- to medium-grained semipelitic schist; and fine-grained granular to weakly schistose psammitic granulite;

psammitic beds increase upward; apparent thickness 5,500 feet or more..

4.3 Subsurface Soil Condition

Soil types were grouped into the major zones noted on the boring log. A brief explanation of the terms and notes used in the log is included with this report. The

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stratification lines designating the interfaces between earth materials on the boring log are approximate; in situ, the transitions may be gradual. Detailed soil descriptions and depth of various soil strata are given in the boring log, together with SPT blow counts with depth. In general, the encountered soils are grouped into major types and summarized as follows:

Silty Sand: Light brown and gray silty sand with mica and gravel was encountered and extended to depth 5.5 ft below existing ground elevation. N-values for this soil type ranged from 5 to 11 blows per foot (bpf).

Sandy Clay: Light gray and brown sandy clay with mica was encountered underneath the Silty Sand and extended to completion depth of the boring. N-values for this soil type ranged from 2 to 20 bpf.

4.4 Groundwater Observation

The borehole was observed for the presence and level of groundwater while drilling and immediately after completion of drilling operation. As noted on the boring log, groundwater was encountered during and after drilling, and a summary is presented in the table below. Water level observations are presented along the left side of the boring log, near the middle. Fluctuations in the level and quantity of groundwater may occur due to variations in rainfall, temperature, soil permeability and other factors not evident at the time of the water level measurements recorded on the boring log.

SUMMARY OF GROUNDWATER OBSERVATION

Boring No. Boring Depths (ft)

Groundwater Encountered at Drilling below Existing Grade (ft)

Groundwater Encountered at Completion below Existing Grade (ft)

SB-01 15 12 9

5.0 ANALYSIS AND RECOMMENDATIONS

5.1 Thrust Restraint

The thrust forces in the pipelines due to hydrostatic and hydrodynamic forces should be restrained by using thrust blocks. Thrust forces occur in pipeline where the direction or size of the pipe changes, therefore it is necessary to provide thrust blocks at bends, reducers, offsets, tees, wyes, dead ends and valves. Based on the location, soil borings, the design criteria are provided in the following table:

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SUMMARY OF ENCOUNTERED SOIL PROPERTIES

Location Soil Type USCS N-Value Range

Range of Effective

Unit Weight, (pcf)

Range of Friction Angle, (deg.)

Friction Angle b/n Soil and

DIP*, fc (deg.)

SB-1

(6’ to 10’) Sandy Clay CL 2 to 5 100 to 105 10 to 14 8

Note*: DIP: Ductile Iron Pipe

Very soft and soft sandy clay were encountered at the anticipated water line and trust block embedment depths. These encountered materials considered unstable and should be undercut, replaced, and compacted with suitable fill materials.

5.2 Meter Vault Foundation

Following general meter vault design criteria, it is common that excavation on the order of 8 to 12 feet from the existing ground surface may be required to establish meter vault foundations. With the anticipated light structural loads, a foundation system comprised of a shallow footing founded on engineered fill, could be utilized.

Based on the boring data, the engineering properties of the encountered soils at, or about, the expected meter vault foundations are summarized in the following table. Soil parameters are based on laboratory results, empirical correlation between the SPT and laboratory data, and published information.

SUMMARY OF ENCOUNTERED SOIL PROPERTIES

Location Soil Type USCS Range of N-Values

Range of Effective Unit Weight, (pcf)

Range of Angle of Internal Friction, Bearing Capacity

(psf)

SB-01

(8’ to 13’)

Sandy Clay CL 2 to 4 100 to 105 10 to 14 1500*

SB-01

(13’ to 15’)

Sandy Clay CL 20 105 to 110 10 to 14 2500

* Very soft and soft sandy clay were encountered at the anticipated meter vault foundation elevation. These encountered materials should be undercut, replaced, and compacted with suitable fill materials.

The recommended bearing value is based on a minimum factor of safety of 2.5 with respect to measured shear strength of natural soils and anticipated shear strength of properly-compacted select fill. The bearing capacity at the final footing elevation should

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be verified in the field by the geotechnical engineer to ensure the bearing capacity at the bottom of the footing excavation is adequate for the design loads.

5.3 Below Grade Wall

Below-grade walls retaining soils and fills will be subjected to lateral earth pressures. The magnitude of lateral earth pressure will depend upon the type and density of the backfill and/or natural soil adjacent to the wall, the rigidity of the wall and the drainage conditions behind the wall. It is expected that the walls will be fixed at each corner, as well as a top slab, restricting rotation about the wall base.

The design lateral earth pressure should be 50 psf and 40 psf equivalent fluid pressures for cohesive and granular backfill, respectively, per vertical foot of wall. These values assume a fixed wall (at-rest earth pressure condition) and both drained and full hydrostatic pressure conditions. The wall design should also account for any surcharge loads within a 45-degree slope from the base of the wall. Wall surcharge loads must also be considered in the design. Lateral earth pressure coefficient values of 0.5 and 0.3 are considered suitable for the sand and clean stone backfill, respectively, in consideration of surcharge loads.

The design lateral earth pressures provided above do not include a factor of safety. Surcharge due to a sloping ground surface above the wall and other loads located adjacent to, and above, the base of the wall can have significant influence in lateral earth pressure and should be considered during design. Furthermore, there is no provision in the above pressures for hydrostatic loading on the wall.

5.4 Excavation

The excavation for side walls may be open cut or will require temporary support.

All excavations should be performed in accordance with the latest Occupational Safety and Health Administration (OSHA) requirements. The OSHA soil classification system categorizes soil and rock deposits in hierarchy of Stable Rock, Type A, Type B, and Type

C, in decreasing order of stability as follows:

Stable Rock is natural solid mineral matter that can be excavated with vertical sides and remain intact while exposed.

Type A Soils are cohesive soils with an unconfined compressive strength of

1.5 tons per square foot (tsf) or greater. Examples of cohesive soils are: clay, AB Job No.: 2020534.12 Page 8

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silty clay, sandy clay, clay loam and, in some cases, silty clay loam and sandy clay loam. Cemented soils such as caliche and hardpan are also considered

Type A.

Type B Soils: Includes (i) cohesive soil with an unconfined compressive strength greater than 0.5 tsf but less than 1.5 tsf or (ii) Granular cohesionless soils including: angular gravel (similar to crushed rock), silt, silt loam, sandy loam and, in some cases, silty clay loam and sandy clay loam, or (iii) previously disturbed soils except those which would otherwise be classified as

Type C soil, or (iv) soil that meets the unconfined compressive strength or cementation requirements for Type A, but is fissured or subject to vibration;

or (v) dry rock that is not stable; or (vi) material that is part of a sloped, layered system where the layers dip into the excavation on a slope less steep than four horizontal to one vertical (4H:1V), but only if the material would otherwise be classified as Type B.

Type C Soils: Includes (i) Cohesive soil with an unconfined compressive strength of 0.5 tsf (48 kPa) or less; or (ii) Granular soils including gravel, sand, and loamy sand; or (iii) Submerged soil or soil from which water is freely seeping; or (iv) Submerged rock that is not stable; or (v) Material in a sloped, layered system where the layers dip into the excavation on a slope of four horizontal to one vertical (4H:1V) or steeper.

Very soft clay and sandy soil were encountered, which are categorized as a Type

C soil in accordance with the OSHA soil classification system. The maximum allowable side slopes for unsupported/free-standing short-term excavation less than 20 feet deep in is 1.5 horizontal to 1 vertical 1.5H:1V or 34 degrees for Type C soils is recommended for this project.

5.5 Structural Fill

All structure-supporting fill and trench backfill material should consist of approved granular material conforming to the requirements in the WSSC Standard

Specifications and should be compacted to a minimum of 95% maximum dry density of the material. All encountered soil materials are considered suitable fills. If unsuitable

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materials are encountered during construction, the soil shall be removed and replaced with suitable fill in accordance with WSSC Standard Specification Section – 02315. The maximum dry density of the fill should be determined in accordance with ASTM D698 and the field moisture content of the fill should be within ±2% of its optimum. The nominal loose thickness of each lift of fill material should be between six (6) and eight

(8) inches. Each lift should be properly compacted, tested and approved in accordance with WSSC Standard Specification Section – 02315, prior to placing subsequent lifts.

5.6 Construction Considerations

Positive surface drainage should be established at the start of work, be maintained during construction, and following the completion of the project to prevent surface water ponding and subsequent saturation of subgrade soils. Prolonged exposure or saturation of subgrade soils by ponding or runoff water may result in significant changes in strength and compressibility characteristics. Saturated subgrade soils should be excavated and replaced with suitable materials.

Depending upon weather conditions during and prior to construction, groundwater may be encountered in the excavation areas. Any seepage into the construction excavation could be controlled by pumping from sump pits. During site preparation, surface runoff should be directed away from the construction areas.

6.0 GENERAL COMMENTS

The soil classifications presented in this report are based upon the data obtained from the soil boring performed at indicated locations and from any other information discussed in this report. This report does not reflect any variations that may occur across the site. The nature and extent of such variations may not become evident until construction. If variations do occur, the conclusion and recommendations of this report should then be reviewed by ABC’s geotechnical engineer in light of the new information.

This report has been prepared for the exclusive use of our client for the specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No other warranties, either expressed or implied, are intended or made. In the event that any changes in the nature, design or location of the project as outlined in this report are planned, the conclusions and

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recommendations contained in this report shall not be considered valid unless the changes are reviewed and the conclusions of this report modified or verified in writing by ABC’s geotechnical engineer of record.

AB CONSULTANTS, INC.

APPENDIX

A. General Notes

B. Vicinity Map

C. Boring Plan

D. Boring Log and Lab Test Results

E. Pavement Core Summary

A. GENERAL NOTES

Drilling and Sampling Symbols

Split Auger Shelby Rock Gravel Sand Silt Clay Spoon Cutting Tube Core

(SS) (AU) (ST) (RC)

N = Standard penetration, blows per foot of a 140 lbs hammer for 30" drop RQD = Rock Quality Designation LL = Liquid Limit PL = Plastic Limit PI = Plasticity Index

Cohesionless Soils If the sand or silt content of a soil is great enough, the soil becomes non-cohesive or semi-cohesive. The soil classification becomes SAND or SILT with the other soil constituents being modifying.

Based on N-Value 0 to 4 Blows………….Very Loose 30 to 59 Blows……….Dense 5 to 9 Blows………….Loose Over 60 Blows……….Very Dense 10 to 29 Blows……….Medium Dense

Cohesive Soils If clay content is sufficient so that clay dominates soil properties, then CLAY becomes the major soil constituent as modifier. Other minor soil constituents may be added according to classification breakdown for cohesion less soils:

i.e. silty clay, trace of some sand, trace of gravel.

Based on N-Value 0 to 3 Blows………….Very Soft 16 to 30 Blows………..Stiff 4 to 5 Blows………….Soft 30 to 60 Blows………..Very Stiff 6 to 16 Blows………...Firm Over 61 Blows………..Hard

Based on Penetrometer Value Below 0.25…………...Very Soft 1.00 to 1.99…………..Stiff

0.25 to 0.49…………..Soft 2.00 to 3.99…………..Very Stiff

0.50 to 0.99…………..Firm Over 4.00…………….Hard

Quantity Modifiers Term % of Dry Weight trace 0 to 10 little 11 to 20 some 21 to 35 and/with 36 to 50

Particle Size Identifications Boulder ………………………......Over 8 inch diameter Cobbles…………………………...3 inch to 8 inch Gravel…………..Coarse…………1 inch to 3 inch

Medium……….1/2 inch to 1 inch Fine…………....4.75 mm to 1/2 inch

Sand…………....Coarse……….....2 mm to 4.75 mm Medium………..0.425 mm to 2 mm Fine…………....0.075 mm to 0.425 mm

Silt/Clay………………………......Below 0.075 mm

B. VICINITY MAP

One Large Water Valve and Vault Replacement

Montgomery County, Maryland

N

WSSC CONTRACT # BT7370A22

JOB NO: 2020534-12

SCALE: N.T.S.

DATE: 11/20/2023

SITE

C. BORING PLAN

NOTE: TO AVOID POTENTIAL MORTAR

COATING FROM VIBRATION,

MECHANIZED DRILLING IS NOT

PERMITTED WITHIN 10 FEET OF LIVE

PCCP MAIN

D. BORING LOG and LAB TEST RESULTS

5.5

15.0

Moist, Medium Dense to Loose, Light Brown and Gray, SILTY SAND (SM), with mica and gravel

Moist, Very Soft to Stiff, Light Gray and Brown, SANDY CLAY (CL), with mica

Bag sample taken between 1 and 6 ft

% Passing No. 200 =36.6

% Passing No. 200 =52

End of Boring @ 15 ft, Backfilled borehole upon completion.

5-5-6

3-2-3

2-2-2

1-1-1

10-10-10

100%

67%

33%

17%

17%

14.1

17.3

22.8

22.6

41.5

1.0- 2.5

3.5- 5.0

6.0- 7.5

8.5- 10.0

13.5- 15.0

338.50

329.00

S-1

S-2

S-3

S-4

S-5

Rig Type

Rig No.

Drive Hammer

Casing Auger Size

Size of Core

Size of Bit OD

Hammer Energy Ratio

Auger Depth

WATER TABLE CAVE-IN TABLE

Elev (ft) Time

(hours)

11/7/23

12.0 @ 0

11/7/23

D.L.F.G.

11.0 333.0

LB

IN

IN

IN

FT

Truck

45B

Date

Inspector

Depth Below Surface

332.0

Depth Below Surface

@ Drilling 11/7/23

Driller

335.0 @ 0

D.L.

11/7/23

11/7/23

Date Started Date Completed

Logged by

Depth (ft)Elev (ft) DateTime

(hours)Depth (ft)

9.0

1of

NMC (%)

Sheet 1 of

REC (%)

M A

T L

Northing

Boring

SPT- Standard Penetration Test

1303713 499119

T-206

BT7370A22

SB-01

Contract No.

Geotech Consultant/ContractorConsultant

REC - RecoveryPI - Plasticity Index

LL - Liquid Limit

Legend: NMC - Natural Moisture Content

RQD - Rock Quality Designation Elev - Elevation

MATL- Material Graphics

Geotech - Geotechnical OD - Outside Diameter

BLOWS/

RQD

SAMPLE

NO.

Easting

REMARKSSAMPLE

DEPTH LL (%)

SPT SPOON/ROCK CORE

PI (%)

Boring and Sampling Conforms to ASTM/AASHTO:

LAB. INDEX TESTSDEPTH

IN

FEET

MATERIAL DESCRIPTION

ELEV.

IN

FEET

TSG/GEO/01

8-31-2015

The Wilson T. Ballard Co.

Project Description

Boring No. Station Ground Surface Elevation

WASHINGTON SUBURBAN SANITARY COMMISSION

STANDARD BORING LOG

Large Water Valve And Vault Replacement

AB Consultants, Inc.

344.0 ft, '

W S

S C

S T

A N

D A

R D

B O

R

IN

G L

O G

[L E

T T

E R

S

IZ

E

W S

S C

_T E

M P

LA

T

E .G

D T

-1

LA

R G

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M V

R E

P

LA

C E

M E

N T

B

T

A

A

N D

B T

A

.G P

J

/1

7/

0.0010.010.1110100

DEPTH

Cobbles Gravel

Particle size (mm)

P e r c e n t

P a s s i n g

Sand Silt Clay coarse fine coarse medium fine

SB-01 1.0BOREHOLE NO.

GRAIN SIZE DISTRIBUTION

Phone:

Fax:

AB Consultants inc

CLIENT:

PROJECT NO.:

PROJECT:

SITE:

U S

_G S

D _D

O U

B

LE

-1

LA

R

G E

W M

V R

E P

LA

C

E M

E N

T

B T

A

A N

D B

T

A

.G

P J

A B

_C O

N S

.G D

T

1/

/2

0.0010.010.1110100

DEPTH

Cobbles Gravel

Particle size (mm)

P e r c e n t

P a s s i n g

Sand Silt Clay coarse fine coarse medium fine

SB-01 8.5BOREHOLE NO.

0.0010.010.1110100

COBBLES

GRAVEL SAND

SB-01

SB-01

100 1403 2 4 fine coarse

SILT OR CLAY

1.0

8.5

16 20 30 4016 60 fine

HYDROMETERU.S. SIEVE NUMBERS

36.6

52.0

D100 D60

Cu

SB-01

SB-01

D10

LL PL

0.381

0.141

4.75

2001.5 medium

6 810 14

Specimen Identification

Specimen Identification

Classification PI Cc

GRAIN SIZE DISTRIBUTION

GRAIN SIZE IN MILLIMETERS

coarse

U.S. SIEVE OPENING IN INCHES

0.213

1.0

8.5

3/4 1/23/8

24.2

0.0

39.2

48.0

P E

R C

E N

T F

IN

E

R B

Y W

E

IG

H T

%Gravel %Sand

%SiltD50 %Clay

Phone:

Fax:

AB Consultants inc

CLIENT:

PROJECT NO.:

PROJECT:

SITE:

U S

_G R

A

IN

_S

IZ

E

-1

LA

R G

E W

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LA

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B

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A

A

N D

B T

A

.G P

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B _C

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1/

6/

Sample Description: Gray and Tan Clayey Sand with mica Classification: SC / A-2-6 Test Method: A Soil Engineering Properties Sieve No. % Passing Liquid Limit: 35 3" 100.0 Plastic Limit: 19 1 1/2" 100.0 Plasticity Index: 16 3/4" 100.0 Proctor Data and Results 3/8" 98.4 Max. Unit Dry Weight 128.0 lbs/cu.ft. 4 95.0 Opt. Water Content 9.6 % 10 92.5 Corr. Max. Unit Dry Weight n/a 40 74.8 Corr. Opt. Water Content n/a 200 41.6

AB CONSULTANTS, INC. Job No.: 2020534-12 9450 Annapolis Road Project: Large Valve and Vault Replacement Lanham, Maryland 20706 Sample No.: Bag (1-6) Tel: 301-306-3091 Sample Location: SB-1 Fax: 301-306-3092 Test Date: 11/16/2023

LABORATORY COMPACTION TEST RESULT

Modified Effort (ASTM D1557 / AASHTO T180)

Gradation

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

U ni tD ry

W ei gh t( lb s/ cu .ft

Water Content (%)

ZAV curve for S.G.=2.7

SB-01 1.0 38 37 14.1

SB-01 3.5 17.3

SB-01 6.0 22.8

SB-01 8.5 4.75 52 22.6

SB-01 13.5 41.5

Plastic Limit

Plasticity Index

Maximum Size (mm)

%<#200 Sieve

Liquid Limit

Satur-ation

Void Ratio

Summary of Laboratory Results

Borehole

Sheet 1 of 1

Class-ification

Water Content

Dry Density

(pcf) Depth

Phone:

Fax:

AB Consultants inc

CLIENT:

PROJECT NO.:

PROJECT:

SITE:

U S

_L A

B _S

U M

M A

R Y

-1

LA

R G

E W

M V

R E

P

LA

C E

M E

N T

B

T

A

A

N D

B T

A

.G P

J A

B _C

O N

S .G

D T

1/

6/

The Wilson T. Ballard Company

BT7370A22

Large Water Valve and Vault Replacement Montgomery County, Maryland

E. PAVEMENT CORE SUMMARY

Pavement Core Report November 17, 2023 AB Job No.: 2020534-12 Page 1 WSSC Water Contract #: BT7370A22

AB CONSULTANTS, INC

Coring Number

Bituminous Pavement Thickness Picture

Surface Course

(in.)

Base Course

(in.)

Total Thickness

(in.)

PC-01 1.0 2.5 3.5