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REPORT COVER PAGE

Preliminary Geotechnical Engineering Report Falcon Project- McKamey Parcels

Gregory, Texas

March 2, 2018

Terracon Project No. 90185016

Prepared for:

Hanson Professional Services, Inc.

Corpus Christi, Texas

Prepared by:

Terracon Consultants, Inc.

Corpus Christi, Texas

REPORT TOPICS

REPORT TOPICS

EXECUTIVE SUMMARY ................................................................................................ 1

INTRODUCTION ............................................................................................................. 2SITE CONDITIONS ......................................................................................................... 2GEOTECHNICAL CHARACTERIZATION ...................................................................... 3PROJECT DESCRIPTION .............................................................................................. 5GEOTECHNICAL OVERVIEW ....................................................................................... 6EARTHWORK................................................................................................................. 6PRELIMINARY FOUNDATION RECOMMENDATIONS ................................................ 8SEISMICITY .................................................................................................................. 10CORROSION CONSIDERATIONS ............................................................................... 11CONSIDERATIONS FOR FINAL GEOTECHNICAL STUDY ....................................... 12GENERAL COMMENTS ............................................................................................... 13

Note: This report was originally delivered in a web-based format. Orange Bold text in the report indicates a referenced

heading. The PDF version also includes hyperlinks which direct the reader to that section. For more interactive features,

please view your project online at client.terracon.com.

ATTACHMENTS

EXPLORATION AND TESTING PROCEDURES

SITE LOCATION AND EXPLORATION PLAN

EXPLORATION RESULTS (Boring Logs, Subsurface Profile)

CORROSION TEST RESULTS

SUPPORTING INFORMATION (General Notes and Unified Soil Classification System)

http://client.terracon.com/

Preliminary Geotechnical Engineering Report

Falcon Project- McKamey Parcels ■ Gregory, Texas

March 2, 2018 ■ Terracon Project No. 90185016

Responsive ■ Resourceful ■ Reliable 1

EXECUTIVE SUMMARY

This summary should be used in conjunction with the entire report for design purposes. It should

be recognized that details were not included or fully developed in this section, and the report must

be read in its entirety for a comprehensive understanding of the items contained herein. The section

titled General Comments should be read for an understanding of the report limitations.

Based on the information obtained from our subsurface exploration, pertinent geotechnical

considerations include the following:

The subsurface soils consist of Fat Clay (CH), Lean Clay (CL) and Silty Sand (SM).

Groundwater was encountered between 17 and 18½ feet during and after the drilling

operations and between 5½ and 8½ feet below existing grade after about three weeks.

The Potential Vertical Rise (PVR) at this site is about 1 to 3½ inches in its present condition.

Conventional shallow foundations or slab-on-grade foundations can be used to support lightly

loaded structures and other equipment. The foundations and slabs should bear on a properly

compacted subgrade consisting of approved imported select fill and/or reworked onsite soils.

Deep foundations should be considered for heavy concentrated loads. The site is suitable

for conventional drilled pier foundations, auger-cast-in-place (ACIP) piles, and driven piles.

The 2015 International Building Code IBC seismic site classification for this site is D.

This report is for a preliminary, reconnaissance level study and should not be used for

design purposes.


NTRODUCTION


Falcon Project- McKamey Parcels

US Hwy 81

Gregory, Texas Terracon Project No. 90185016

March 2, 2018

INTRODUCTION

This report presents the results of our subsurface exploration and geotechnical engineering

services performed for the above project to be located near US Hwy 81 in Gregory, Texas. The

project was authorized by Mr. Terald E. Smith through issuance of Task Order No. 1011, executed

on January 31, 2018. The project was performed in general accordance with Terracon Proposal

No. P90185016, dated January 18, 2018.

The purposes of this report are to describe the subsurface conditions observed at the borings

drilled for this study, analyze and evaluate the test data, and provide preliminary

recommendations with respect to:

subsurface soil conditions groundwater conditions

preliminary earthwork preliminary foundation

This report is for a preliminary, reconnaissance level study and should not be used for design

purposes. Additional laboratory, field and engineering analysis will be required. The field activity

was delayed due to bad weather conditions and soft soil at the project site.

Maps showing the site and boring locations are shown in the Site Location and Exploration

Plan sections, respectively. The results of the laboratory testing performed on soil samples

obtained from the site during the field exploration are included on the boring logs in the

Exploration Results section of this report.

SITE CONDITIONS

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

field exploration and our review of publicly available geologic and topographic maps.





Item Description

Parcel information

The site is located north of US Hwy 81 between McKamey Road and

Midway Road about 3 miles west of Gregory, Texas. The overall

dimensions of the site are about 9,700 feet by 11,000 feet.

Existing improvements

Mostly cultivated farmland and range land. There are some cotton storage

pads. There is an existing building with a pond close to boring location

SB-1.

Current ground cover The site is vegetated with grass and shrubs. The agricultural fields were

ploughed at the time of our field activities.

Existing topography The site is sloping downward from southwest to northeast.

GEOTECHNICAL CHARACTERIZATION

We have developed a general characterization of the subsurface soil and groundwater conditions

based upon our review of the data and our understanding of the geologic setting. The following

page provides a graphical representation of characterization. A statistical summary of field and

laboratory data is also included.

The geotechnical characterization as illustrated on the subsequent page forms the basis of our

geotechnical calculations and evaluation of site preparation, foundation options and pavement

options. As noted in General Comments, the characterization is based upon widely spaced

exploration points across the site, and variations are likely.

Site Geology

The Corpus Christi Sheet (1975) of the Geologic Atlas of Texas published by the Bureau of

Economic Geology of the University of Texas at Austin has mapped the Beaumont Formation

(Qb) of Quaternary Geologic Age at this site. The Beaumont formation consists of clay, silt, sand,

and gravel deposits deposited by stream channels, point bars, natural levee and backswamp

deposits. The site is included in an area of Qbs with a stippled overprint, indicating deposits of

primarily clay and mud of low permeability, high water holding capacity, high compressibility, high

to very high shrink-swell potential, poor drainage, low shear strength, and high plasticity.

Subsurface Profile

Based on the results of the borings, subsurface conditions at the boring locations can be

generalized as indicated in the table below. A profile of the subsurface conditions is presented on

the Exhibit A-6. Note that these five widely spaced borings revealed significantly varying

conditions at the site, particularly in regards to the presence or absence of the near surface lean

clays, as well as the depth/presence of major sand layers.





Stratum Approximate Depth to

Bottom of Stratum (feet) Material Description

Consistency/

Density

IA 0 to 1 FILL: CLAYEY GRAVEL (GC); brown and

tan. (Observed in boring SB-1 only) ---

I 0 to 8 FAT CLAY (CH) 1; dark brown, brown Medium Stiff to

Hard

II 1 to 13 LEAN CLAY (CL) 2; dark brown, brown, tan Medium Stiff to

Hard

III 4 to 50 FAT CLAY (CH) 1; tan and light gray Stiff to Hard

IV

8 to 29

SILTY SAND (SM) 3; light gray

Loose to

Medium Dense

33 to 50 Medium Dense

to Dense

V 29 to 100 FAT CLAY (CH) 1; tan and light gray Medium Stiff to

Hard

1 FAT CLAY (CH) materials could undergo high to very high volumetric changes (shrink/swell)

should they experience changes in their in-place moisture content. The surficial dark brown clay

will be removed during the stripping grubbing operation.

2 The LEAN CLAY (CL) materials could undergo moderate volumetric changes (shrink/swell) should

they experience changes in their in-place moisture content.

3 The SILTY SAND (SM) materials could undergo low volumetric changes (shrink/swell) should they

experience changes in their in-place moisture content. These materials are considered

volumetrically stable with regards to change in moisture content due to their granular nature.

Conditions encountered at each boring location are indicated on the individual boring logs shown

in the Exploration Results section and are attached to this report. Stratification boundaries on

the boring logs represent the approximate location of changes in native soil types; in situ, the

transition between materials may be gradual.

Groundwater Conditions

The borings were typically drilled to their full depths using dry drilling techniques to aid in the

observation of groundwater during drilling activities. The boreholes were observed while drilling for

the presence and level of groundwater. Groundwater levels observed in the borings are tabulated

below:





Boring No. During Drilling

(feet) 1,2

After Drilling

(feet) 1,2

Cave-in depth

after drilling (feet) 1

Piezometer Water

Level (feet) 1, 4

SB-1 18 18½ 31 8½

SB-2 17 18 33 ---5

SB-3 ---3 ---3 ---3 6

SB-4 17 18 31½ 5½

SB-5 18½ --- 16 ---6

1 Below existing ground level. The groundwater levels and cave-in depths are rounded to the nearest

½ feet.

2 Temporary piezometers were installed beside the drilled boring locations to observe the

groundwater level variations over a period of time.

3 Wet rotary drilling was used to advance the boring below 10-ft depth which precluded water level

measurement.

4 Readings were taken on February 26, 2018.

5 The installed piezometer was missing.

6 The site was too wet to access to the piezometer location

The borings were backfilled with soil cuttings after the drilling operations were completed.

Groundwater generally appears as either a permanent or temporary water source. Permanent

groundwater is generally present year round, which may or may not be influenced by seasonal

and climatic changes. Temporary groundwater is also referred to as a “perched” water source,

which generally develops as a result of seasonal and climatic conditions.

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, the foundation

contractor should check the groundwater conditions just before foundation excavation activities.

The borings were backfilled with soil cuttings after the drilling operations and groundwater

observations were completed.

PROJECT DESCRIPTION

Our initial understanding of the project was provided in our proposal and was discussed in the

project planning stage. A period of collaboration has transpired since the project was initiated,

and our final understanding of the project conditions is as follows:

Item Description

Project description

No specific project information has been provided other than this

preliminary study will be done for site selection purposes for a future major

industrial complex.

Building construction We anticipate both shallow and deep foundation systems will be

considered for this project.





Item Description

Finished floor elevation Not available.

Grading/slopes Not available.

GEOTECHNICAL OVERVIEW

Expansive Soil Considerations

Based on our findings, the subsurface soils at this site generally exhibit a low to very high

expansion potential. Based on the information developed from our field and laboratory programs

and on method TEX-124-E in the Texas Department of Transportation (TxDOT) Manual of Testing

Procedures, we estimate that the subgrade soils in the building area exhibit a Potential Vertical

Rise (PVR) of about 1 to 3½ inches in its present condition. The actual movements could be

greater than the values presented in this report if inadequate drainage, ponded water, and/or

other sources of moisture are allowed to infiltrate beneath the structure after construction. Based

on the PVR results, building subgrade modifications to provide a uniform soil support for

foundation will be required and are discussed in this report.

EARTHWORK

Earthwork will include clearing and grubbing, excavations and fill placement. The following

sections provide recommendations for use in the preparation of specifications for the work. These

recommendations include critical quality criteria as necessary to render the site in the state

considered in our geotechnical engineering evaluation for foundations, floor slabs, and

pavements.

Wet Weather/Soft Subgrade Considerations

Due to the high capacity of holding the moisture in surficial soils, proper compaction may be

difficult to achieve. In addition, construction during and soon after wet weather periods may

encounter difficulties due to wet and soft surficial soils becoming a general hindrance to

equipment as a result of rutting and/or pumping of the soil surface. This condition is primarily due

little to no confining pressure near the ground surface. If the subgrade cannot be adequately

compacted to the minimum densities as described above, one of the following methods should

be used to improve the soils: 1) removal and replacement with select fill, 2) chemical treatment of

the soil to dry the subgrade, or 3) drying by natural means if the schedule allows.

Based on our experience with similar soils, chemical treatment is the most efficient and effective

method to increase the supporting value of wet and soft subgrade such as that observed at this

site. Chemical treatment may be necessary to depths of approximately 12 to 24 inches or greater

of the near-surface soils, depending on the condition of the subgrade at the time of construction.

We suggest that a cost be included in the construction budget for chemical treatment of the soils





using a lime-flyash mixture to produce drying and to improve the condition of the soil if the

subgrade is wet and/or soft at the time of construction. We recommend that this cost be in the

form of a contingency or allowance to be used, if needed.

Site Preparation

Prior to construction, existing vegetation and root material should be removed. Complete stripping

of the topsoil should be performed in any of the proposed building and parking/driveway areas,

there by exposing the marl/limestone subgrade.

The subgrade should be proof-rolled. Proof-rolling can be performed with an adequately loaded

vehicle such as a fully loaded tandem axle dump truck. The proof-rolling should be performed

under the direction of the Geotechnical Engineer. Areas which excessively deflect under the

proof-roll should be delineated and subsequently addressed by the Geotechnical Engineer.

Excessively wet or dry material should either be removed or moisture conditioned and

recompacted.

Fill Material Types

Select and general fill should meet the following material property requirements:

Soil Type 1 USCS Classification Acceptable Parameters (for Select Fill)

Granular Select Fill Varies Upper 6 inches of the building pad

Select fill CL

(LL≤40) and (7≤PI≤20) All locations and elevations

On-site soils CL, CH

CH soils are not suitable to use as select fill.

CL soils can be used as select fill provided that they

meet the criteria of select fill.

1. Prior to any filling operations, samples of the proposed borrow and on-site materials should be

obtained for laboratory moisture-density testing. The tests will provide a basis for evaluation of fill

compaction by in-place density testing. A qualified soil technician should perform sufficient in-place

density tests during the filling operations to evaluate that proper levels of compaction, including dry

unit weight and moisture content, are being attained.

2. Granular select fill should consist of 2014 TxDOT Item 247, Type A, Grade 1-2 crushed limestone

base material. Plasticity Index (PI) should range from 5 to 15





Fill Compaction Requirements

Select and general fill should meet the following compaction requirements.

Item Select Fill

Fill Lift Thickness All fill should be placed in thin, loose lifts of about 8 inches, with compacted thickness not exceeding 6 inches.

Compaction of On-Site Soil/ Select Fill Soil/ Granular Select Fill

95 percent of materials standard Proctor maximum dry density (ASTM D 698).

Moisture content of Select Fill Soil/

Granular Select Fill

The materials should be moisture conditioned between -2 and +3

percentage points of the optimum moisture content.

Moisture content of Onsite Clay Soil

The materials should be moisture conditioned between 0 and +4 percentage points of the optimum moisture content.

PRELIMINARY FOUNDATION RECOMMENDATIONS

We have assumed various types of structures are planned for the proposed developments at this

site. Based on the field and laboratory data available, along with our previous experience, for

lightly-loaded areas, foundation systems such as slab-on-grade or shallow speed/strip footing

foundations, mat foundations may be considered. Conventional drilled pier foundations, auger

cast in place (ACIP) and driven concrete piles may be utilized to support the heavily loaded

structures at this site. Preliminary geotechnical guidelines for these types of foundation systems

are presented in the following subsections, along with other geotechnical engineering

considerations for this project.

Shallow Foundation System

Shallow foundations may be used for light to moderately loaded structures where some total and

differential settlements can be tolerated. Shallow foundations may include slab-on-grade, shallow

spread footings, or mat foundations.

Slab-on-Grade- Lightly loaded structures may be supported on slab-on-grade foundation

systems. As previously stated, the existing PVR at the site is about 1 to 3½ inches in its present

condition. For structures where the floor slab could tolerate a nominal amount of movement,

supporting the floor slab at grade is a possibility provided proper subgrade preparation is

implemented. The most conventional means of subgrade preparation would be to provide a pad

of select fill beneath the floor slab to help reduce the PVR values to more acceptable levels. For

the subgrade conditions observed in our test borings, we estimate removal of the near-surface

clay and replacement with approximately 2 to 5 feet of select fill soils underneath the floor slab

area would be required to reduce the estimated PVR to about one inch or less, which is a value

often considered tolerable by structural engineers and/or owners. The actual degree of subgrade

preparation for the structures planned at this site will need to be evaluated based on the level of

performance desired by the owner. For structures that are highly sensitive to movement, we





anticipate that structural suspension of the floor slab above the subgrade to isolate the floor

system from the soil movements would be required.

The estimated levels of subgrade preparation provided above are based upon widely spaced

borings and assumed information regarding site grading and finished floor elevations. The

subgrade preparation could vary from that reported above particularly in cases where finished

floor elevations differ significantly from the existing ground surface elevation due to cut and/or fill

conditions.

Description Preliminary Design Parameters

Minimum grade beam embedment

depth 24 to 30 inches below exterior grade

Allowable bearing capacity 2,00 to 2,500 psf

Spread/Strip Footings

Description Preliminary Design Parameters

Minimum embedment below existing

grade1 2 to 3 feet

Allowable bearing pressures

(Individual footings) 2,500 to 3,000 psf

Allowable bearing pressure (strip

footing) 2 2,000 to 2,500 psf

1. To bear within the select fill soils.

2. Defined as footings at least twice as long as wide.

Mat Foundation

A mat foundation can be designed as a uniform thick concrete member to support the structures.

The mat, regardless of the design, should bear no less than 4 feet below the final exterior grades.

The mat should be analyzed using a soil-structure interaction program to identify areas of high

contact stresses, excessive movements and large moments. A subgrade modulus (k1) of 60 to

80 pci for a 1 ft by 1 ft plate on the prepared subgrade can be used. The modulus value may be

adjusted for the actual mat size. A net allowable bearing pressure of 1,500 psf to 2,500 psf with

a FOS of 3 may be used to design the mat. Maximum contact pressure should not exceed the

allowable net bearing pressure.





Deep Foundations

Settlement sensitive structures and heavily loaded structures should be founded on deep

foundations. We consider this site suitable for the use of conventional drilled shafts, augered

cast-in-place (ACIP) piles, and driven piles. Both precast, pre-stressed (PCPS) concrete piles

and steel pipe or H piles may be considered.

The minimum shaft or pile size, depth, allowable skin friction, allowable end bearing, along with

the desired bearing stratum should be evaluated for each structure. Minimum depths of about 25

to 30 feet should be anticipated. Higher capacities can be achieved with greater depths. For

preliminary design purposes, allowable skin side resistance ranging from about 600 to 800 psf

can be expected. The upper 5 ft of the shaft/pile below the existing or final ground surface,

whichever is lower, will likely be neglected for side resistance. In addition, the allowable end

bearing values could range from 8 to 10 ksf. Additionally, end bearing values in a competent, and

consistent sand layer will be substantially higher.

Pile groups subjected to axial loads can be affected by numerous factors which may include pile

type, size and length, pile spacing, overall group size, loading conditions, installation procedures

and soil type and strength. With a center-to-center spacing of at least 3 pile widths or diameters,

the group effect will be insignificant on the bearing capacity of the piles for pile groups smaller

than 9 piles. For laterally loaded pile groups, a larger pile spacing, perhaps on the order of 5 to

8 pile diameters or widths, may be necessary to avoid group effects.

SEISMICITY

The site is in a relatively non-seismic area of Texas. We do not expect seismicity to have a

significant impact on the project. However, a detailed seismic analysis was beyond our scope.

Description Value

2015 International Building Code Site Classification (IBC) 1 D 2

Site Latitude 27.95562° N

Site Longitude 97.31917° W

SDS Spectral Acceleration for a Short Period 3 0.066g

SD1 Spectral Acceleration for a 1-Second Period 3 0.021g

1. Seismic site classification in general accordance with the 2015 International Building Code, which refers to 2010

ASCE-7.

2. Borings extended to a maximum depth of 100 feet.

3. The Spectral Acceleration values were determined using publicly available information provided on the United

States Geological Survey (USGS) website. The spectral acceleration values can be used to determine the site

coefficients using Tables 1613.3.3 (1) and 1613.3.3 (2) in the 2015 IBC.





CORROSION CONSIDERATIONS

Steel and concrete elements in contact with soil possibly are subject to degradation due to

corrosion or chemical attack. Therefore, buried steel and concrete elements should be designed

to resist corrosion and degradation based on accepted practices. We performed analytical tests

on three selected soil samples to evaluate the soil corrosion potential. The test results are

summarized in the following table.

General discussions regarding the corrosion of steel and the degradation of concrete with respect

to the results of the analytical tests are provided below.

Steel

The corrosion potential of steel is influenced by electrical resistivity, chloride ion concentration,

and pH. Corrosion of steel is more likely in soil environments with low resistivity, high chloride ion

concentrations, or low pH. The following table presents general guidelines for estimating the

corrosion potential of steel as a function of chloride ion concentration, pH, and electrical resistivity

Resistivity, ohm-cm Chloride Content, ppm pH Corrosion Potential

0 – 1,000 >500

0 – 4.5 Very High

1,000 – 2,000 4.5 – 5.5 High

2,000 – 5,000 <500

5.5 – 6.5 Moderate

> 5,000 > 6.5 Mild

Each of the columns in the above table should be used independently of the others for estimating

corrosion potential. For example, it is not necessary to have a resistivity between 0 and 1000

ohm-cm and a pH between 0 and 4.5 to indicate a Very High potential for corrosion potential. The

results indicate that the potential for corrosion due to chloride ion concentration may be high and

is mild due to pH in the samples tested. Based on the electrical resistivity results, the corrosion

potential for buried steel is generally high. We recommend that a Corrosion engineer be consulted

to recommend appropriate protective measures.

Sample Approximate

Depth, feet pH

Total

Chloride, ppm

Sulfate,

ppm

Electrical Resistivity,

ohm-cm

SB-1 2 – 4 8.15 1160 90.4 1,700

SB-3 4 – 6 8.20 886 170 1,900

SB-5 8 – 10 9.04 1460 485 1,100





Concrete

The degradation of concrete is caused by chemical agents in the soil or groundwater that react

with concrete to either dissolve the cement paste or precipitate compounds which cause cracking

and flaking. The concentration of water-soluble sulfates in the soils is a good indicator of the

potential for chemical attack of concrete. Sulfate concentrations in soil can be used to evaluate

the need for protection of concrete based on the following table

Water Soluble Sulfate Content In

Soil, (percent by mass)

Water Soluble Sulfate

Content In Soil, (ppm)

Severity of Potential

Exposure

> 2.0 > 10,000 Class 3

0.2 – < 2.0 1,500 – 10,000 Class 2

>0.1 – < 0.2 150 – 1,500 Class 1

0.0 – 0.1 0 – 150 Class 0

The results of sulfate tests on the selected soil samples from this study indicate the potential for

exposure of concrete, based on sulfate ion concentrations, is Class 1 in the site soils. We

recommend that a corrosion engineer be consulted to determine if protective measures are

warranted. According to ACI, the use of Type II, or equivalent, cement should be appropriate.

CONSIDERATIONS FOR FINAL GEOTECHNICAL STUDY

As indicated earlier, this reconnaissance geotechnical study was for screening purposes and

preliminary site evaluation; it is not adequate for final design. If development of the property

proceeds, a final detailed geotechnical study will be required. The following items are

recommended for inclusion in the final study.

We recommend the final exploration of the site included a combination of

conventional geotechnical borings as well as cone penetration tests (CPT). Final

boring and CPT locations should be strategically selected based on the f inal site

layout. Due to the variability of the sand layers encountered, a number of deep

borings should be drilled in the areas where pile foundations are being considered.

CPT soundings should be performed with a relatively heavy unit, likely a 25-ton

truck-mounted rig, to ensure adequate penetration. To gain access to the

locations, this will require the fieldwork to be done during a dry weather period,

unless all-weather roads are prepared.

A reconnaissance-level geologic growth fault study should be performed.





GENERAL COMMENTS

Our analysis and opinions are based upon our understanding of the geotechnical conditions in

the area, the data obtained from our site exploration and from our understanding of the project.

Variations will occur between exploration point locations, 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. Terracon should be retained as the Geotechnical

Engineer, where noted in the final report, to provide observation and testing services during

grading, excavation, foundation construction and other earth-related construction phases of the

project. If variations appear, we can provide further evaluation and supplemental

recommendations. If variations are noted in the absence of our observation and testing services

on-site, we should be immediately notified so that we can provide evaluation and supplemental

recommendations.

Our scope of services 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 studies should be undertaken. Additionally, a geologic fault

study was beyond our scope.

Our services and any correspondence are intended for the sole benefit and exclusive use of our

client for specific application to the project discussed and are accomplished in accordance with

generally accepted geotechnical engineering practices with no third party beneficiaries intended.

Any third party access to services or correspondence is solely for information purposes only.

Reliance upon the services and any work product is limited to our client, and is not intended for

third parties. Any use or reliance of the provided information by third parties is done solely at their

own risk. 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.

Site safety, and cost estimating including, excavation support, and dewatering

requirements/design are the responsibility of others. If changes in the nature, design, or location

of the project are planned, our conclusions and recommendations shall not be considered valid

unless we review the changes and either verify or modify our conclusions in writing.




Responsive ■ Resourceful ■ Reliable

EXPLORATION AND TESTING PROCEDURES

Field Exploration

Boring Locations No. of Borings Approximate Depth Below

Existing Grade, ft.

Site Center 1 100

Site Quadrants 4 50

We installed temporary standpipe piezometers (wells) to about 23 feet depth to allow for

groundwater level observations for a longer period. The piezometers were installed in companion

borings near each of the sample borings.

Boring Layout and Elevations: Unless otherwise noted, Terracon personnel provide the boring

layout. Coordinates are obtained with a handheld GPS unit (estimated horizontal accuracy of

about ±10 feet).

Subsurface Exploration Procedures: We advance the soil borings with a truck-mounted, using

air rotary drilling techniques. Five samples are obtained in the upper 10 feet of each boring and at

intervals of 5 feet thereafter. Soil sampling is performed using a split-barrel sampling procedures.

We observe groundwater levels during drilling and sampling. For safety purposes, all borings are

backfilled with auger cuttings after their completion.

The sampling depths, penetration distances, and other sampling information are recorded on the

field boring logs. The samples are placed in appropriate containers and taken to our soil laboratory

for testing and classification by a geotechnical engineer. Our exploration team prepares field boring

logs as part of the drilling operations. These field logs include visual classifications of the materials

encountered during drilling and our interpretation of the subsurface conditions between samples.

Final boring logs are prepared from the field logs. The final boring logs represent the geotechnical

engineer's interpretation of the field logs and include modifications based on observations and

tests of the samples in our laboratory.

Laboratory Testing

Samples retrieved during the field exploration were taken to the laboratory for further observation

by the project geotechnical engineer and were classified in accordance with the Unified Soil

Classification System (USCS) described in this Appendix. At that time, the field descriptions were

confirmed or modified as necessary and an applicable laboratory testing program was formulated

to determine engineering properties of the subsurface materials.

Laboratory tests were conducted on selected soil samples and the test results are presented in

this appendix. The laboratory test results were used for the geotechnical engineering analyses,





and the development of foundation and earthwork recommendations. Laboratory tests were

performed in general accordance with the applicable ASTM, local or other accepted standards.

Selected soil samples obtained from the site were tested for the following engineering properties:

Moisture Content

Atterberg Limits

Soils Finer than No. 200 Mesh Sieve

Unconfined Compressive Test (UC Test)

Unconsolidated Undrained test (UU Test)

Corrosion Tests

Sample Disposal

All samples were returned to our laboratory. The 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 other arrangements are made prior to the disposal period.


SITE LOCA TION AND EXPLORATI ON PLANS

SITE LOCATION AND EXPLORATION PLANS

SITE LOCATION



ROAD MAP PROVIDED BY MICROSOFT BING MAPS

EXPLORATION PLAN



DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES

SITE MAP PROVIDED BY GOOGLE EARTH

SB-1

SB-2

SB-3

SB-4

SB-5

EXPLORATION RESULTS

EXPLORATION RESULTS

0.72

1.50

3.86

37

19

16

16

19

17

20

25

29

27

42

17

18

26

89

111

113

35-19-16

24-14-10

2.25 (HP)

4.0 (HP)

4.5+ (HP)

2.5 (HP)

2.5 (HP)

3-6-9N=15

3-5-8N=13

4.25 (HP)

3.5 (HP)

3.25 (HP)

3.5 (HP)

4.5+ (HP)

5-6-9N=15

1.0

10.0

50.0

STRATUM IAFILL: CLAYEY GRAVEL (GC); brown and tanSTRATUM IILEAN CLAY (CL); dark brown, very stiff to hard

- tan below 6 feet

- Clayey Sand (SC) seams at 8 feet

STRATUM IIIFAT CLAY (CH); tan, stiff to hard- with ferrous stains to 15 feet

- tan and light gray below 18 feet

Boring Terminated at 50 Feet

GR

AP

HIC

LO

G

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

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TE

D F

RO

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INA

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OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

901

850

16 M

CK

AM

EY

PA

RC

ELS

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/2/1

8

UN

CO

NF

INE

DC

OM

PR

ES

SIV

ES

TR

EN

GT

H (

tsf)

PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

LL-PL-PI

ATTERBERGLIMITS

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

20

25

30

35

40

45

50

SA

MP

LE T

YP

E

FIE

LD T

ES

TR

ES

ULT

S

US Hwy 81 Gregory, TexasSITE:

Page 1 of 1

Advancement Method:Hollow Stem

Abandonment Method:Boring backfilled with Auger Cuttings and/or Bentonite

Notes:

Project No.: 90185016

Drill Rig: CME 75

Boring Started: 02-09-2018

BORING LOG NO. SB-1Hanson Professional Services, Inc.CLIENT:Corpus Christi, Texas

Driller: Enviro Core

Boring Completed: 02-09-2018

Exhibit: A-1

PROJECT: Falcon Project- McKamey Parcels

6911 Blanco RdSan Antonio, TXCaved at 31 feet at completion of drilling

18 feet while drilling18.5 feet at completion of drilling8.5 feet after 3 weeks in adjacent piezometer

Caved at 31 feet at completion of drilling

WATER LEVEL OBSERVATIONS18 feet while drilling18.5 feet at completion of drilling8.5 feet after 3 weeks in adjacent piezometer

DEPTH

LOCATION See Exhibit A-2

Latitude: 27.9655° Longitude: -97.3187°

1.49

33

28

26

27

25

27

24

27

28

33

21

25

23

25

92

56-21-35

45-23-22

74-27-47

1.25 (HP)

2.0 (HP)

2.75 (HP)

0.75 (HP)

1.75 (HP)

3.5 (HP)

4-6-7N=13

4-9-9N=18

4.0 (HP)

8-19-21N=40

3-8-18N=26

3-5-8N=13

3-10-20N=30

8.0

33.0

50.0

STRATUM IFAT CLAY (CH); dark brown, medium stiff to very stiff

- Lean Clay (CL) seams at 6 feet, tan

STRATUM IIIFAT CLAY (CH); tan and light gray, stiff to very stiff

- Clayey Sand (SC) seams at 19 feet

STRATUM IVSILTY SAND (SM); light gray, medium dense to dense

- with clay seams below 43 feet


GR

AP

HIC

LO

G


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

901

850

16 M

CK

AM

EY

PA

RC

ELS

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/2/1

8

UN

CO

NF

INE

DC

OM

PR

ES

SIV

ES

TR

EN

GT

H (

tsf)

PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

LL-PL-PI

ATTERBERGLIMITS

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

20

25

30

35

40

45

50

SA

MP

LE T

YP

E

FIE

LD T

ES

TR

ES

ULT

S


Page 1 of 1



Notes:


Drill Rig: CME 75





Exhibit: A-2



17 feet while drilling18 feet at completion of drilling


WATER LEVEL OBSERVATIONS17 feet while drilling18 feet at completion of drilling

DEPTH



1.04

4.20

11

27

27

21

20

21

29

32

28

25

27

21

17

17

95

109

54-27-27

35-17-18

78-28-50

2.0 (HP)

2.25 (HP)

2.25 (HP)

4.5+ (HP)

4-4-5N=9

0.25 (HP)

6-10-14N=24

7-11-14N=25

2.0 (HP)

3.25 (HP)

4.5+ (HP)

4-9-15N=24

3-6-9N=15

4.0

13.0

29.0

STRATUM IFAT CLAY (CH); dark brown, very stiff

STRATUM IILEAN CLAY (CL); brown, stiff to hard

STRATUM IVSILTY SAND (SM); light gray, medium dense

STRATUM VFAT CLAY (CH); tan and light gray, medium stiff to hard

GR

AP

HIC

LO

G


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

901

850

16 M

CK

AM

EY

PA

RC

ELS

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/2/1

8

UN

CO

NF

INE

DC

OM

PR

ES

SIV

ES

TR

EN

GT

H (

tsf)

PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

LL-PL-PI

ATTERBERGLIMITS

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

20

25

30

35

40

45

50

SA

MP

LE T

YP

E

FIE

LD T

ES

TR

ES

ULT

S


Page 1 of 2

Advancement Method:Hollow Stem: 0'-10'Mud Rotary: 10'-100'


Notes:


Drill Rig: CME 75





Exhibit: A-3


6911 Blanco RdSan Antonio, TX6 feet after 3 weeks in adjacent piezometer

WATER LEVEL OBSERVATIONS

DEPTH



4.79

3.22

1.77

21

34

31

32

25

21

19

36

34

105

101

88

6-8-12N=20

3.75 (HP)

4.0 (HP)

4.5+ (HP)

4.0 (HP)

4.5+ (HP)

6-9-10N=19

4.5+ (HP)

4.5+ (HP)

4.5+ (HP)100.0

STRATUM VFAT CLAY (CH); tan and light gray, medium stiff to hard (continued)


GR

AP

HIC

LO

G


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

901

850

16 M

CK

AM

EY

PA

RC

ELS

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/2/1

8

UN

CO

NF

INE

DC

OM

PR

ES

SIV

ES

TR

EN

GT

H (

tsf)

PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

LL-PL-PI

ATTERBERGLIMITS

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

55

60

65

70

75

80

85

90

95

100

SA

MP

LE T

YP

E

FIE

LD T

ES

TR

ES

ULT

S


Page 2 of 2

Advancement Method:Hollow Stem: 0'-10'Mud Rotary: 10'-100'


Notes:


Drill Rig: CME 75





Exhibit: A-3


6911 Blanco RdSan Antonio, TX6 feet after 3 weeks in adjacent piezometer

WATER LEVEL OBSERVATIONS

DEPTH



4.12

2.72

4.68

36

20

18

19

22

23

25

32

23

33

22

15

20

24

103

103

117

41-13-28

30-18-12

58-23-35

2.25 (HP)

2.0 (HP)

2.25 (HP)

1.0 (HP)

2-3-5N=8

2-3-6N=9

2-4-6N=10

4.5+ (HP)

3.75 (HP)

3.0 (HP)

4.5+ (HP)

4.5+ (HP)

4-7-15N=22

2.0

8.0

17.0

50.0

STRATUM IFAT CLAY (CH); dark brown, very stiffSTRATUM IILEAN CLAY (CL); brown, medium stiff to very stiff

STRATUM IVSILTY SAND (SM); light gray, loose, with clay seams

STRATUM IIIFAT CLAY (CH); tan and light gray, stiff to hard


GR

AP

HIC

LO

G


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

901

850

16 M

CK

AM

EY

PA

RC

ELS

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/2/1

8

UN

CO

NF

INE

DC

OM

PR

ES

SIV

ES

TR

EN

GT

H (

tsf)

PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

LL-PL-PI

ATTERBERGLIMITS

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

20

25

30

35

40

45

50

SA

MP

LE T

YP

E

FIE

LD T

ES

TR

ES

ULT

S


Page 1 of 1



Notes:


Drill Rig: CME 75





Exhibit: A-4


6911 Blanco RdSan Antonio, TXCaved at 31.5 feet at completion of drilling

17 feet while drilling18 feet at completion of drilling5.5 feet after 3 weeks in adjacent piezometer

Caved at 31.5 feet at completion of drilling

WATER LEVEL OBSERVATIONS17 feet while drilling18 feet at completion of drilling5.5 feet after 3 weeks in adjacent piezometer

DEPTH



2.72

1.53

99

39

35

32

35

33

28

36

32

34

29

18

18

20

97

88

73-26-47

93-26-67

0.75 (HP)

0.75 (HP)

1.25 (HP)

2.0 (HP)

2.0 (HP)

3.25 (HP)

2-3-5N=8

2-4-7N=11

3.0 (HP)

3.25 (HP)

6-8-12N=20

8-14-18N=32

3.25 (HP)

4.0

50.0

STRATUM IFAT CLAY (CH); dark brown, medium stiff

STRATUM IIIFAT CLAY (CH); tan, stiff to hard- with ferrous stain between 5 and 15 feet

- tan and light gray below 18 feet


GR

AP

HIC

LO

G


TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

GE

O S

MA

RT

LO

G-N

O W

ELL

901

850

16 M

CK

AM

EY

PA

RC

ELS

.GP

J T

ER

RA

CO

N_D

AT

AT

EM

PLA

TE

.GD

T 3

/2/1

8

UN

CO

NF

INE

DC

OM

PR

ES

SIV

ES

TR

EN

GT

H (

tsf)

PE

RC

EN

T F

INE

S

WA

TE

RC

ON

TE

NT

(%

)

DR

Y U

NIT

WE

IGH

T (

pcf)

LL-PL-PI

ATTERBERGLIMITS

WA

TE

R L

EV

EL

OB

SE

RV

AT

ION

S

DE

PT

H (

Ft.)

5

10

15

20

25

30

35

40

45

50

SA

MP

LE T

YP

E

FIE

LD T

ES

TR

ES

ULT

S


Page 1 of 1



Notes:


Drill Rig: CME 75





Exhibit: A-5



18.5 feet while drilling


WATER LEVEL OBSERVATIONS18.5 feet while drilling

DEPTH



-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

0 5 10 15 20 25 30 35 40 45-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

00 5 10 15 20 25 30 35 40 45

BT-50.0 Ft.

SB-1

BT-50.0 Ft.

SB-2

BT-100.0 Ft.

SB-3

BT-50.0 Ft.

SB-4

BT-50.0 Ft.

SB-5

NOTES:

ClayeyGravel Lean Clay Fat Clay Silty Sand

BoreholeNumber

Liquid and Plastic Limits

ARBT

LL PLMoistureContent

%w

SB-1

Water level reading at time of drilling.

Water level at adjacent piezometer.

Sampling(See General Notes)

Dep

th -

Fee

t

Distance Along Baseline - Feet

Explanation

BoreholeLithology

BoreholeTermination Type

See Exhibit A-2 for orientation of soil profile.See General Notes in Appendix C for symbols and soil classifications.Soils profile provided for illustration purposes only.Soils between borings may differAR - Auger RefusalBT - Boring Termination

6911 Blanco RdSan Antonio, TX

PH. 210-641-2112 FAX. 210-558-7894

SUBSURFACE PROFILE EXHIBITProject Manager:

FALCON PROJECT- MCKAMEY PARCELSUS HWY 81

GREGORY, TEXAS

File Name: 90185016

Scale: NTS


Drawn by: TA

Date: 3/2/2018

Approved by:

TH

IS B

OR

ING

LO

G IS

NO

T V

ALI

D IF

SE

PA

RA

TE

D F

RO

M O

RIG

INA

L R

EP

OR

T.

SM

AR

T F

EN

CE

90

1850

16

MC

KA

ME

Y P

AR

CE

LS.G

PJ

TE

RR

AC

ON

_DA

TA

TE

MP

LAT

E.G

DT

3/2

/18

A-6

CORROSION TEST RESULTS

Project: McKamy Site

Project Number: 90185016

Project Manager: Bailey Welch

Reported:Terracon

6911 Blanco Rd. 02/23/18 10:50

San Antonio TX, 78216

Report No. 1802206

NELAC Cert. No.:

Received:

02/15/18 12:39

LABORATORY REPORT

Additional Notes:

T104704360-17-17

Sample Matrix: Solid

Sample ID #: SB-1 2-4 Dark Brown Clay Lab Sample ID #: 1802206-01Sampling Method: Grab

Date/Time Collected: 02/15/18 08:00

Analyte Result PQL Batch Analyzed MethodUnits Analyst NotesPrep Method

General Chemistry

02/22/18 17:400.01 B808107 ASTMD11251700 ohms-cm JLResistivity

02/22/18 16:570.004 B808106 ASTM C158090.4 % JLSulfate ASTM C1580

02/22/18 15:001.00 HB808108 EPA 9045C8.15 pH Units JLpH *

02/22/18 15:001.0 HB808108 EPA 170.120 °C JLpH measured @Temperature >>

Anions by Ion Chromatography

02/21/18 13:341.00 B808097 EPA 300.01160 mg/kg JLChloride * EPA 300.0

1610 S. Laredo Street, San Antonio, Texas 78207-7029 (210) 229-9920 Fax (210) 229-9921www.satestinglab.com Page 3 of 8




Reported:Terracon

6911 Blanco Rd. 02/23/18 10:50


Report No. 1802206

NELAC Cert. No.:

Received:

02/15/18 12:39

LABORATORY REPORT

Additional Notes:

T104704360-17-17


Sample ID #: SB-3 4-6 Brown Clay Lab Sample ID #: 1802206-02Sampling Method: Grab



General Chemistry


02/22/18 16:570.004 B808106 ASTM C1580170 % JLSulfate ASTM C1580





1610 S. Laredo Street, San Antonio, Texas 78207-7029 (210) 229-9920 Fax (210) 229-9921www.satestinglab.com




Reported:Terracon

6911 Blanco Rd. 02/23/18 10:50


Report No. 1802206

NELAC Cert. No.:

Received:

02/15/18 12:39

LABORATORY REPORT

Additional Notes:

T104704360-17-17


Sample ID #: SB-5 8-10 Light Brown Clay Lab Sample ID #: 1802206-03Sampling Method: Grab



General Chemistry


02/22/18 16:570.04 B808106 ASTM C1580485 % JLSulfate ASTM C1580





1610 S. Laredo Street, San Antonio, Texas 78207-7029 (210) 229-9920 Fax (210) 229-9921www.satestinglab.com Page 5 of 8

SUPPORTING INFORMA TION

SUPPORTING INFORMATION

PLASTICITY DESCRIPTION

Term

< 1515 - 29> 30

Descriptive Term(s)of other constituents

Water InitiallyEncountered

Water Level After aSpecified Period of Time

Major Componentof Sample

Percent ofDry Weight

(More than 50% retained on No. 200 sieve.)Density determined by Standard Penetration Resistance

Includes gravels, sands and silts.

Hard

Unconfined CompressiveStrength, Qu, tsf

Very Loose 0 - 3 0 - 6 Very Soft less than 0.25

7 - 18 Soft 0.25 to 0.50

10 - 29 19 - 58 0.50 to 1.00

59 - 98 Stiff 1.00 to 2.00

> 99 2.00 to 4.00

LOCATION AND ELEVATION NOTES

SA

MP

LIN

G

FIE

LD

TE

ST

S

(HP)

(T)

(b/f)

(PID)

(OVA)

DESCRIPTION OF SYMBOLS AND ABBREVIATIONS

Descriptive Term(Density)

Non-plasticLowMediumHigh

BouldersCobblesGravelSandSilt or Clay

10 - 18

> 50 15 - 30 19 - 42

> 30 > 42

_

Hand Penetrometer

Torvane

Standard PenetrationTest (blows per foot)

Photo-Ionization Detector

Organic Vapor Analyzer

Water levels indicated on the soil boringlogs are the levels measured in theborehole at the times indicated.Groundwater level variations will occurover time. In low permeability soils,accurate determination of groundwaterlevels is not possible with short termwater level observations.

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

DESCRIPTIVE SOIL CLASSIFICATION

Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracyof such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey wasconducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographicmaps of the area.

Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dryweight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils haveless than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, andsilts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may beadded according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are definedon the basis of their in-place relative density and fine-grained soils on the basis of their consistency.

Plasticity Index

01 - 1011 - 30

> 30

RELATIVE PROPORTIONS OF FINES

Descriptive Term(s)of other constituents

Percent ofDry Weight

< 55 - 12> 12

TraceWithModifier

Water Level Aftera Specified Period of Time

GRAIN SIZE TERMINOLOGYRELATIVE PROPORTIONS OF SAND AND GRAVEL

TraceWithModifier

Standard Penetration orN-Value

Blows/Ft.

Descriptive Term(Consistency)

Loose

Very Stiff

Standard Penetration orN-Value

Blows/Ft.

Ring SamplerBlows/Ft.

Ring SamplerBlows/Ft.

Medium Dense

Dense

Very Dense

0 - 1 < 3

4 - 9 2 - 4 3 - 4

Medium-Stiff

8 - 15

5 - 9

30 - 50

WA

TE

R L

EV

EL

Auger

Shelby Tube

Ring Sampler

Grab Sample

Split Spoon

Macro Core

Rock Core

No Recovery

RELATIVE DENSITY OF COARSE-GRAINED SOILS

Particle Size

Over 12 in. (300 mm)12 in. to 3 in. (300mm to 75mm)3 in. to #4 sieve (75mm to 4.75 mm)#4 to #200 sieve (4.75mm to 0.075mmPassing #200 sieve (0.075mm)

ST

RE

NG

TH

TE

RM

S

> 4.00

4 - 8

GENERAL NOTES

UNIFIED SOIL CLASSIFICATION SYSTEM



UNIFIED SOI L CLASSI FICATI ON 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 1 Cc 3 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 1 Cc 3 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 50

Inorganic: PI 7 and plots on or above “A” line

J

CL Lean clay K,L,M

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

Organic: Liquid limit - oven dried

0.75 OL Organic clay K,L,M,N

Liquid limit - not dried 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: Liquid limit - oven dried

0.75 OH Organic clay K,L,M,P

Liquid limit - not dried 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 =

6010

2

30

DxD

)(D

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.

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