Geotechnical Report - 3 Tower Addition.pdf

Report Cover Page

21-313 Houston VAMC

EHRM – Three Tower

Additions Geotechnical Data Report

August 29, 2024 | Terracon Project No. 92245303

Prepared for:

Apogee Consulting Group, P.A.

1151 Kildaire Farm Road, Suite 120

Cary, North Caroline 27511

21-313 Houston VAMC EHRM – Three Tower Additions | Houston, Texas

Facilities | Environmental | Geotechnical | Materials i

Table of Contents

Introduction

Project Description

Site Conditions

Geotechnical Characterization

Geology

Subsurface Profile

Groundwater Conditions

General Comments

Figures GeoModel

Attachments

Exploration and Testing Procedures Site Location and Exploration Plan

Exploration and Laboratory Results (Boring log and Laboratory Data)

Supporting Information (General Notes and Unified Soil Classification

System)

Note: This report was originally delivered in a web-based format. Blue Bold text in the report indicates a referenced section heading. The PDF version also includes hyperlinks which direct the reader to that section and clicking on the logo will bring you back to this page. For more interactive features, please view your project online at client.terracon.com.

Refer to each individual Attachment for a listing of contents.

http://client.terracon.com/

Facilities | Environmental | Geotechnical | Materials 1

Introduction

This report presents the results of our subsurface exploration and geotechnical laboratory services performed for the proposed three tower additions within the existing Michael E.

DeBakey Veterans Affair (VA) Medical Center located at 2002 Holcombe Boulevard in

Houston, Texas. The purpose of our services is to provide information relative to:

■ Boring log with field and laboratory data

■ Stratification based on visual soil classification

■ Groundwater levels observed during drilling

■ Site Location and Exploration Plan

■ Subsurface exploration procedures

■ Description of subsurface conditions

The geotechnical field and laboratory Scope of Services for this project included the advancement of three test borings (B-1 through B-3) to a depth of approximately 50 feet below existing grade, laboratory testing, and preparation of this data report.

Maps showing the site and boring locations are shown on the Site Location and

Exploration Plan, respectively. The results of the laboratory testing performed on soil samples obtained from the site during our field exploration are included on the boring log in the Exploration and Laboratory Results section.

Project Description

Our initial understanding of the project was provided in our cost estimate document and was discussed during project planning. A period of collaboration has transpired since the project was initiated, and our final understanding of the project conditions is as follows:

Facilities | Environmental | Geotechnical | Materials 2

Item Description

Project Description

The project consists of the construction of three tower additions on the south side of the existing Michael E. DeBakey

VA Medical Center. The scope of work covered under this data report consists of providing subsurface information in the areas of the proposed improvements. Once our findings are discussed with Apogee, it will be determined if Terracon needs to prepare a geotechnical engineering report with below-grade construction considerations and foundation recommendations for the design and construction of the proposed tower additions utilizing the information from this data report.

Site Conditions

The following description of site conditions is derived from our site visit in association with the field exploration.

Item Description

Project Location

The project is within the existing Michael E. DeBakey VA

Medical Center located at 2002 Holcombe Boulevard in

Houston, Texas.

See Site Location

Existing

Improvements

The project is occupied by a seven-story building with associated concrete sidewalks and pavements. We understand an underground tunnel with final floor elevation at approximately 10 feet below existing grade is located below each proposed tower.

Current Ground Cover Grass, weeds, scattered trees, and concrete

Existing Topography Relatively level

Geotechnical Characterization

Geology

Based on the geologic maps published by the Bureau of Economic Geology, the site for the proposed construction is located on the Beaumont Formation, a deltaic nonmarine

Pleistocene deposit. The Beaumont Formation is heterogeneous containing thick interbedded layers of clay, fine sand, and silt.

Facilities | Environmental | Geotechnical | Materials 3

The clay fraction is primarily composed of montmorillonite, illite, kaolinite, and finely ground quartz. The clay present in the formation has been preconsolidated by a process of desiccation. Numerous wetting and drying cycles have produced a network of small randomly oriented, closely-spaced joints within some depth zones. These small joints frequently have a shiny appearance and the clays are called slickensided in these cases.

The joint pattern may have an influence on the construction and engineering behavior of the soil.

The coastal plain in this region has a complex tectonic geology, several major features of which are: Gulf Coastal geosyncline, salt domes, and major sea level fluctuations during the glacial stages, subsidence and geologic faulting activities. Most of these geologic faulting activities have ceased for millions of years, but some are still active. A detailed geologic fault investigation and study of the site geology are beyond the scope of this report.

Subsurface Profile

We have developed a general characterization of the subsurface conditions based upon our review of the subsurface exploration, laboratory data, geologic setting, and our understanding of the project. This characterization is termed GeoModel. Conditions observed at each exploration point are indicated on the individual logs. The individual logs can be found in the Exploration and Laboratory Results and the GeoModel can be found in the Figures section of this report.

We identified the following model layers within the subsurface profile. For a more detailed view of the model layer depths at each boring location, refer to the GeoModel.

Facilities | Environmental | Geotechnical | Materials 4

Model

Layer Layer Name General Description

Fill: Lean Clay and

Sandy Lean Clay reddish brown, with scattered gravel and ferrous stains

2 Fat Clay gray, tan, reddish brown, medium stiff to very stiff with sand and silt seams, ferrous stains, calcareous nodules, and slickensides

Lean Clay, Sandy

Lean Clay and Silty

Clay gray, tan, reddish brown, soft to very stiff, with sand and silt seams, and ferrous stains

4 Silty Sand gray and reddish brown, loose to medium dense, with clay pockets

Groundwater Conditions

Borings B-1 through B-3 were advanced using dry drilling techniques to their termination depth (about 50 feet) in an effort to evaluate groundwater conditions at the time of our field program. Upon reaching groundwater, drilling was suspended for a period of about

15 minutes to allow groundwater to rise and the groundwater levels to be recorded. The water levels observed in the boreholes can be found in the boring logs and are summarized below.

Summary of Groundwater Level Observation

Boring No.

Approximate

Depth of Dry

Drilling (feet) 1

Approximate Depth of Groundwater Below

Existing Grade (feet)

Initial/

During Dry

Drilling

After 5

Minutes

After 15

Minutes

B-1 50 23 22 22

B-2 50 27 23 21

B-3 50 23 22½ 22½

1. Below existing grade.

Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project and should be evaluated prior to construction.

Facilities | Environmental | Geotechnical | Materials 5

General Comments

Our work is conducted with the understanding of the project as described in the cost estimate. Variations will occur across the site or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction.

Our scope of services for this project does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other services should be undertaken.

This data report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical practices with no third-party beneficiaries intended. No warranties, either express or implied, are intended or made.

Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing.

Facilities | Environmental | Geotechnical | Materials

Figures

Contents:

GeoModel

D E

P T H

B E

L O

W E

X

IS

T

IG

G R

A D

E

F e e t)

Layering shown on this figure has been developed by the geotechnical engineer for purposes of modeling the subsurface conditions as required for the subsequent geotechnical engineering for this project.

Numbers adjacent to soil column indicate depth below ground surface.

NOTES:

B-1 B-2 B-3

Legend

This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.

GeoModel

2002 Holcombe Boulevard | Houston, Texas

Terracon Project No. 92245303

21-313 - Houston VAMC EHRM- 3 Tower Additions

11555 Clay Rd, Ste 100

Houston, TX

Third Water Observation Second Water Observation First Water Observation

Groundwater levels are temporal. The levels shown are representative of the date and time of our exploration. Significant changes are possible over time.

Water levels shown are as measured during and/or after drilling. In some cases, boring advancement methods mask the presence/absence of groundwater. See individual logs for details.

Concrete Fill

Fat Clay with Sand Fat Clay

Silty Clay Silty Sand

Sandy Lean Clay Lean Clay

Model Layer Layer Name General Description

1 reddish brown, with scattered gravel and ferrous stains

3 gray, tan, reddish brown, soft to very stiff, with sand and silt seams, and ferrous stains

4 gray and reddish brown, loose to medium dense, with clay pockets gray, tan, reddish brown, medium stiff to very stiff with sand and silt seams, ferrous stains, calcareous nodules, and slickensides

Fill: Lean Clay and Sandy Lean Clay

Lean Clay, Sandy Lean Clay, and Silty

Clay

Silty Sand

Fat Clay

22.523

22.5

Attachments

Exploration and Testing Procedures

Field Exploration

Number of Borings Approximate Boring

Depth 1 (feet) Boring Location

3 (B-1 through B-3) 50 Proposed tower addition areas

1. Below grade at the time of our field program.

Boring Layout and Elevations: We used handheld Global Positioning System (GPS) equipment to locate the approximate latitude and longitude of the borings with an accuracy of +/-25 feet. The boring depths were measured from the existing ground surface at the time of our field activities.

Subsurface Exploration Procedures: We advanced the soil borings with an all-terrain-vehicle

(ATV)-mounted drilling equipment using solid stem auger techniques. Ten samples were obtained in the upper 20 feet of each boring and at intervals of 5 feet thereafter. Soil sampling was typically performed using open-tube and/or split-barrel sampling procedures.

Cohesive soil samples were recovered using open-tube samplers. Hand penetrometer tests were performed on samples of cohesive soils in the field to serve as a general measure of consistency.

Granular soils and soils for which good quality open-tube samples could not be recovered were sampled by means of the Standard Penetration Test (SPT). This test consists of measuring the number of blows (N) required for a 140-pound hammer free falling 30 inches to drive a standard split-spoon sampler 12 inches into the subsurface material after being seated six inches. This blow count or SPT “N” value is used to evaluate the stratum. An automatic SPT hammer was used in advancing the split-spoon sampler at the borings.

We backfilled borings with auger cuttings upon completion. The pavements were patched with ready mixed concrete, as appropriate. Our services did not include repair of the site beyond backfilling our boreholes, and cold patching existing pavements. Excess auger cuttings were dispersed in the general vicinity of the boreholes.

The samples were placed in appropriate containers, taken to our soil laboratory for testing, and classified by a geotechnical engineer. In addition, we observed and recorded groundwater levels during drilling and sampling.

Our exploration team prepared field boring logs as part of standard drilling operations including sampling depths, penetration distances, and other relevant sampling information.

Field logs include visual classifications of materials observed during drilling, and our interpretation of subsurface conditions between samples. Final boring logs, prepared from the field logs, represents an interpretation of the field logs by a geotechnical engineer and includes modifications based on laboratory observation and tests on select samples.

Laboratory Testing

The project engineer reviewed the field data and assigned laboratory tests to better understand the engineering properties of the various soil strata as necessary for this project. Procedural standards noted below are for reference to methodology in general. In some cases, variations to methods were applied because of local practice or professional judgment. Standards noted below include reference to other, related standards. Such references are not necessarily applicable to describe the specific test performed.

■ ASTM D2216 Standard Test Methods for Laboratory Determination of Water

(Moisture) Content of Soil and Rock by Mass

■ ASTM D7263 Standard Test Methods for Laboratory Determination of Density (Unit

Weight) of Soil Specimens

■ ASTM D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity

Index of Soils

■ ASTM D1140 Standard Test Method for Determining the Amount of Materials Finer than No. 200 Sieve in Soils by Washing

■ ASTM D2166/D2166M Standard Test Method for Unconfined Compressive Strength of Cohesive Soil

■ ASTM D2850 Standard Test Method for Unconsolidated-Undrained Triaxial

Compression Test on Cohesive Soils

Based on the results of our field and laboratory programs, we described and classified the soil samples in accordance with the Unified Soil Classification System (USCS).

Samples not tested in the laboratory will be stored for a period of 30 days subsequent to submittal of this report and will be discarded after this period, unless we are notified otherwise.

Site Location and Exploration Plan

Site Location

Exploration Plan

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When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table.

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Site Location

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

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Exploration Plan

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

Exploration and Laboratory Results

Boring Logs (B-1 through B-3)

PAVEMENT, approximately 4 inches of concrete FILL - SANDY LEAN CLAY (CL), reddish brown, with scattered gravel

FAT CLAY WITH SAND (CH), gray and reddish brown, medium stiff to very stiff, with ferrous stains

FAT CLAY (CH), gray and reddish brown, medium stiff to very stiff, with ferrous stains

SILTY CLAY (CL-ML), reddish brown, soft, with silt seams

SILTY SAND (SM), reddish brown, loose, with clay pockets

FAT CLAY (CH), reddish brown, stiff to very stiff, with sand seams

SANDY LEAN CLAY (CL), gray and reddish brown, medium stiff, with silt seams

SILTY SAND (SM), gray, medium dense

Boring Terminated at 50 Feet

Boring Log No. B-1

W at er L ev el

O bs er va tio ns

D ep th

Ft

Facilities | Environmental | Geotechnical | Materials

G ra p h ic

L o g

M o d el

L ay er

15.7

26.4

34.4

27.9

24.1

26.3

4.9

1.3

1.5

3.5

0.83

0.80

1.11

1.84

UC

UC

UC

UU

29-17-12

82-26-56

NP

0.3

4.0

10.0

23.0

28.0

33.0

43.0

48.0

50.0

1.5 (HP)

1.5 (HP)

3.0 (HP)

2.0 (HP)

1.5 (HP)

1.5 (HP)

2.0 (HP)

2.5 (HP)

2.5 (HP)

4.0 (HP)

0.5 (HP)

0.5 (HP)

3.5 (HP)

3.0 (HP)

1.0 (HP)

8-7-7 N=14

2002 Holcombe Boulevard | Houston, Texas

Terracon Project No. 92245303 Houston, TX

11555 Clay Rd, Ste 100

Drill Rig Track

Hammer Type Automatic

Driller Terracon

Logged by C. Keeth

Boring Started 08-09-2024

Boring Completed 08-09-2024

Abandonment Method Boring backfilled with auger cuttings and the surface capped with ready-mix concrete.

Advancement Method Dry augered to 50 feet.

Notes

Water Level Observations

After 15 minutes

After 5 minutes

While drilling

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

21-313 - Houston VAMC EHRM- 3 Tower Additions

S am pl e

T yp e

Pe rc en t

Fi n es

C o n fi n in g Pr es su re (p si

W at er C o n te n t

D ry

U n it

W ei g h t

(p cf

S tr ai n

C o m p re ss iv e S tr en g th

(t sf

T es t T yp e

Atterberg Limits

LL-PL-PI

See Exploration PlanLocation:

Latitude: 29.6994° Longitude: -95.3892°

Depth (Ft.)

Strength Test

Fi el d T es t

R es u lt s

FILL - LEAN CLAY (CL), reddish brown, with scattered gravel

FAT CLAY (CH), gray and reddish brown, stiff to very stiff

- with calcareous nodules 14 to 16 feet

- with silt seams 16 to 23 feet

SILTY CLAY (CL-ML), gray and reddish brown, very stiff, with ferrous stains and silt seams

LEAN CLAY (CL), tan and reddish brown, very stiff, with ferrous stains

FAT CLAY (CH), tan and reddish brown, stiff to very stiff

- with ferrous stains 38 to 43 feet

- with calcareous nodules below 48 feet

Boring Terminated at 50 Feet

Boring Log No. B-2

W at er L ev el

O bs er va tio ns

D ep th

Ft

Facilities | Environmental | Geotechnical | Materials

G ra p h ic

L o g

M o d el

L ay er

43-16-27

77-22-55

51-22-29

0.3

4.0

23.0

28.0

33.0

50.0

21.8

21.8

26.7

34.0

25.5

25.0

4.3

2.8

4.1

1.2

1.26

1.28

1.10

1.29

UC

UC

UC

UU

1.5 (HP)

1.5 (HP)

2.0 (HP)

1.5 (HP)

1.5 (HP)

2.0 (HP)

2.5 (HP)

4.5 (HP)

1.5 (HP)

4.0 (HP)

3.5 (HP)

4.5 (HP)

4.5 (HP)

4.5 (HP)

4.5 (HP)

4.5 (HP)

2002 Holcombe Boulevard | Houston, Texas

Terracon Project No. 92245303 Houston, TX

11555 Clay Rd, Ste 100

Drill Rig Track

Hammer Type Automatic

Driller Terracon

Logged by C. Keeth

Boring Started 08-08-2024

Boring Completed 08-08-2024

Abandonment Method Boring backfilled with auger cuttings and the surface capped with ready-mix concrete.

Advancement Method Dry augered to 50 feet.

Notes

Water Level Observations

After 15 minutes

After 5 minutes

While drilling

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

21-313 - Houston VAMC EHRM- 3 Tower Additions

S am pl e

T yp e

Pe rc en t

Fi n es

C o n fi n in g Pr es su re (p si

Atterberg Limits

LL-PL-PI

See Exploration PlanLocation:

Latitude: 29.6997° Longitude: -95.3886°

Depth (Ft.)

W at er C o n te n t

D ry

U n it

W ei g h t

(p cf

S tr ai n

C o m p re ss iv e S tr en g th

(t sf

T es t T yp e

Strength Test

Fi el d T es t

R es u lt s

FILL - SANDY LEAN CLAY (CL), reddish brown, with scattered gravel and ferrous stains

FAT CLAY (CH), gray and reddish brown, stiff to very stiff

- with ferrous stains 14 to to 48 feet

- with slickensides 18 to 23 feet

SANDY LEAN CLAY (CL), tan, stiff, with sand seams

Boring Terminated at 50 Feet

Boring Log No. B-3

W at er L ev el

O bs er va tio ns

D ep th

Ft

Facilities | Environmental | Geotechnical | Materials

G ra p h ic

L o g

M o d el

L ay er

16.5

34.5

32.7

29.0

20.4

4.2

3.9

3.1

8.9

1.03

1.44

1.32

2.22

0.3

6.0

48.0

50.0

1.5 (HP)

2.0 (HP)

2.0 (HP)

1.5 (HP)

1.5 (HP)

1.5 (HP)

2.0 (HP)

3.0 (HP)

3.0 (HP)

4.0 (HP)

4.0 (HP)

4.0 (HP)

3.0 (HP)

4.5 (HP)

4.5 (HP)

2.0 (HP)

UC

UC

UC

UU

34-17-17

85-27-58

53-17-36

2002 Holcombe Boulevard | Houston, Texas

Terracon Project No. 92245303 Houston, TX

11555 Clay Rd, Ste 100

Drill Rig Track

Hammer Type Automatic

Driller Terracon

Logged by C. Keeth

Boring Started 08-08-2024

Boring Completed 08-08-2024

Abandonment Method Boring backfilled with auger cuttings and the surface capped with ready-mix concrete.

Advancement Method Dry augered to 50 feet.

Notes

Water Level Observations

After 15 minutes

After 5 minutes

While drilling

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

21-313 - Houston VAMC EHRM- 3 Tower Additions

S am pl e

T yp e

Pe rc en t

Fi n es

C o n fi n in g Pr es su re (p si

W at er C o n te n t

D ry

U n it

W ei g h t

(p cf

S tr ai n

C o m p re ss iv e S tr en g th

(t sf

T es t T yp e

Depth (Ft.)

Strength Test

Fi el d T es t

R es u lt s

Atterberg Limits

LL-PL-PI

See Exploration PlanLocation:

Latitude: 29.6999° Longitude: -95.3879°

Supporting Information

General Notes

Unified Soil Classification System

Rock Core Shelby Tube

Standard Penetration Test

Facilities | Environmental | Geotechnical | Materials

> 4.00

2.00 to 4.00

1.00 to 2.00

0.50 to 1.00

0.25 to 0.50 less than 0.25

Unconfined Compressive Strength Qu (tsf)

21-313 - Houston VAMC EHRM- 3 Tower Additions

2002 Holcombe Boulevard | Houston, Texas

Terracon Project No. 92245303 11555 Clay Rd, Ste 100

Houston, TX

N

(HP)

(T)

(DCP)

UC

(PID)

(OVA)

Standard Penetration Test Resistance (Blows/Ft.)

Hand Penetrometer

Torvane

Dynamic Cone Penetrometer

Unconfined Compressive Strength

Photo-Ionization Detector

Organic Vapor Analyzer

Water Level After a Specified Period of Time

Water Level After a Specified Period of Time

Cave In Encountered

Water Level Field Tests

Water Initially Encountered

Sampling

Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated. Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations.

General Notes

Location And Elevation Notes

Exploration point locations as shown on the Exploration Plan and as noted on the soil boring logs in the form of Latitude and Longitude are approximate. See Exploration and Testing Procedures in the report for the methods used to locate the exploration points for this project. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area.

Soil classification as noted on the soil boring logs is based Unified Soil Classification System. Where sufficient laboratory data exist to classify the soils consistent with ASTM D2487 "Classification of Soils for Engineering Purposes" this procedure is used. ASTM D2488 "Description and

Identification of Soils (Visual-Manual Procedure)" is also used to classify the soils, particularly where insufficient laboratory data exist to classify the soils in accordance with ASTM D2487. In addition to USCS classification, coarse grained soils are classified on the basis of their in-place relative density, and fine-grained soils are classified on the basis of their consistency. See "Strength Terms" table below for details. The ASTM standards noted above are for reference to methodology in general. In some cases, variations to methods are applied as a result of local practice or professional judgment.

Exploration/field results and/or laboratory test data contained within this document are intended for application to the project as described in this document. Use of such exploration/field results and/or laboratory test data should not be used independently of this document.

Relevance of Exploration and Laboratory Test Results

Descriptive Soil Classification

> 30

15 - 30

8 - 15

4 - 8

2 - 4

Hard

> 50 Very Stiff

Stiff

Medium Stiff

Soft

Very Soft

30 - 50

10 - 29

4 - 9

0 - 3Very Loose

Loose

Medium Dense

Dense

Very Dense

Relative Density of Coarse-Grained Soils

(More than 50% retained on No. 200 sieve.)

Density determined by Standard Penetration

Resistance

Consistency of Fine-Grained Soils

(50% or more passing the No. 200 sieve.)

Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance

0 - 1

Relative Density Consistency Standard Penetration or

N-Value (Blows/Ft.)

Standard Penetration or N-Value

(Blows/Ft.)

Strength Terms

Unified Soil Classification System

Criteria for Assigning Group Symbols and Group Names Using

Laboratory Tests A

Soil Classification

Group

Symbol Group Name B

Coarse-Grained Soils:

More than 50% retained on No. 200 sieve

Gravels:

More than 50% of coarse fraction retained on No. 4 sieve

Clean Gravels:

Less than 5% fines C

Cu≥4 and 1≤Cc≤3 E GW Well-graded gravel F

Cu<4 and/or [Cc<1 or Cc>3.0] E GP Poorly graded gravel F

Gravels with Fines:

More than 12% fines C

Fines classify as ML or MH GM Silty gravel F, G, H

Fines classify as CL or CH GC Clayey gravel F, G, H

Sands:

50% or more of coarse fraction passes No. 4 sieve

Clean Sands:

Less than 5% fines D

Cu≥6 and 1≤Cc≤3 E SW Well-graded sand I

Cu<6 and/or [Cc<1 or Cc>3.0] E SP Poorly graded sand I

Sands with Fines:

More than 12% fines D

Fines classify as ML or MH SM Silty sand G, H, I

Fines classify as CL or CH SC Clayey sand G, H, I

Fine-Grained Soils:

50% or more passes the

No. 200 sieve

Silts and Clays:

Liquid limit less than

Inorganic:

PI > 7 and plots above “A” line J CL Lean clay K, L, M

PI < 4 or plots below “A” line J ML Silt K, L, M

Organic:

𝐿𝐿 𝑜𝑣𝑒𝑛 𝑑𝑟𝑖𝑒𝑑

𝐿𝐿 𝑛𝑜𝑡 𝑑𝑟𝑖𝑒𝑑

< 0.75 OL

Organic clay K, L, M, N

Organic silt K, L, M, O

Silts and Clays:

Liquid limit 50 or more

Inorganic:

PI plots on or above “A” line CH Fat clay K, L, M

PI plots below “A” line MH Elastic silt K, L, M

Organic:

𝐿𝐿 𝑜𝑣𝑒𝑛 𝑑𝑟𝑖𝑒𝑑

𝐿𝐿 𝑛𝑜𝑡 𝑑𝑟𝑖𝑒𝑑

< 0.75 OH

Organic clay K, L, M, P

Organic silt K, L, M, Q

Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat

A Based on the material passing the 3-inch (75-mm) sieve.

B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name.

C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay.

D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay.

E Cu = D60/D10 Cc =

F If soil contains ≥ 15% sand, add “with sand” to group name.

G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.

H If fines are organic, add “with organic fines” to group name.

I If soil contains ≥ 15% gravel, add “with gravel” to group name.

J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.

K If soil contains 15 to 29% plus No. 200, add “with sand” or

“with gravel,” whichever is predominant.

L If soil contains ≥ 30% plus No. 200 predominantly sand, add

“sandy” to group name.

M If soil contains ≥ 30% plus No. 200, predominantly gravel, add

“gravelly” to group name.

N PI ≥ 4 and plots on or above “A” line.

O PI < 4 or plots below “A” line.

P PI plots on or above “A” line.

Q PI plots below “A” line.

DxD

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