Geotechnical Engineering Report...Geotechnical Engineering Report Proposed Retaining Wall 44ARW-1 Oklahoma City, Oklahoma May 8, 2014 Terracon Project No. 03145071 Responsive Resourceful

Geotechnical Engineering Report Proposed Retaining Wall 44ARW-1

Interstate 235 between N.W. 50th Street and Interstate 44

Oklahoma City, Oklahoma

May 8, 2014

Terracon Project No. 03145071

Prepared for:

Leidos Engineering, LLC


Prepared by:

Terracon Consultants, Inc.


Geotechnical Engineering Report Proposed Retaining Wall 44ARW-1 ■ Oklahoma City, Oklahoma May 8, 2014 ■ Terracon Project No. 03145071

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TABLE OF CONTENTS

Page

1.0 INTRODUCTION.......................................................................................................... 1

2.0 PROJECT INFORMATION .......................................................................................... 1

3.0 SUBSURFACE CONDITIONS ..................................................................................... 2

3.1 Typical Subsurface Profile................................................................................. 2

3.2 Groundwater ..................................................................................................... 3

4.0 ANALYSIS AND RECOMMENDATIONS ..................................................................... 3

4.1 Recommended Geotechnical Engineering Design Parameters........................... 4

4.2 Retaining Wall Stability Analyses....................................................................... 6

4.2.1 Foundation Bearing Capacity ................................................................. 6

4.2.2 Settlement of Reinforced Zone ............................................................... 7

4.2.3 Direct Sliding ......................................................................................... 7

4.2.4 Global Stability of Reinforced Zone......................................................... 8

4.3 Global Stability of Temporary Excavation Slopes ............................................... 8

4.4 Wall Drainage Recommendations ..................................................................... 9

4.5 Construction Considerations ........................................................................... 10

5.0 GENERAL COMMENTS ............................................................................................ 11

APPENDIX A - FIELD EXPLORATION

Exhibit A-1 Boring Location Diagram

Exhibit A-2 Field Exploration Description

Exhibit A-3 to A-6 Borings RW3-8, C-6, B-1, B-2, B-3 & B-4

APPENDIX B - LABORATORY TESTING

Exhibit B-1 Laboratory Test Description

Exhibit B-2 Grain Size Distribution Curves

APPENDIX C - SUPPORTING DOCUMENTS

Exhibit C-1 General Notes

Exhibit C-2 Unified Soil Classification System

Exhibit C-3 Sedimentary Rock Classification

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GEOTECHNICAL ENGINEERING REPORT

PROPOSED RETAINING WALL 44ARW-1

INTERSTATE 235 BETWEEN

N.W. 50TH STREET AND INTERSTATE 44

OKLAHOMA CITY, OKLAHOMA Terracon Project No. 03145071

May 8, 2014

1.0 INTRODUCTION

This report presents the results of our geotechnical engineering services performed for the

proposed retaining wall 44ARW-1 to be located on the east side of Interstate 235, from

approximately 280 feet south of NW 50th Street extending north approximately 1,075 feet in

Oklahoma City, Oklahoma. Exploration of the subsurface materials at the project site

consisted of four additional borings (B-1 to B-4) taken to depths of approximately 10 to 15

feet. Subsurface information collected from borings RW3-8 and C-6 provided in our

geotechnical report No. 03115012 dated 8/30/2011 and 03115101 dated 4/15/2011 was

also used in developing our recommendations.

The purpose of these services is to provide information and geotechnical engineering

recommendations relative to:

subsurface soil conditions groundwater conditions

design and construction of the MSE retaining wall

2.0 PROJECT INFORMATION

The retaining wall will be a mechanically stabilized earth (MSE) wall located on Interstate

235 between Stations 271+75 and 282+50. The wall height will vary from about 12 to 35

feet and support a 4(H) or 3(H) to 1(V) slope above it comprised of natural soil/rock, and

additional or existing fill. The wall location is currently covered with vegetation and existing

grades vary from about El. 1125 to El. 1148. Grades in front of the wall will vary from El.

1107 to El. 1128. Based on the boring elevations and preliminary wall profile provided, we

anticipate up to 33 feet of cut will be necessary to construct the retaining wall and lower the

existing grades for the proposed I-235 northbound lane. The wall will be designed and

constructed based on a contractor supplied design. We anticipate that the wall will be

constructed with either a modular block facing or panel facing with either extensible or in

extensible earth reinforcement.



3.0 SUBSURFACE CONDITIONS

3.1 Typical Subsurface Profile

Specific conditions encountered at each boring location are indicated on the individual bor ing

logs. Stratification boundaries on the boring logs represent the approximate location of

changes in soil types; in-situ, the transition between materials may be gradual. Details for each

of the borings can be found on the boring logs included in Appendix A of this report. Based on

the results of the borings, subsurface conditions on the project site can be generalized as

follows:

Subsurface conditions along the I-235 44ARW-1 can be divided into two categories, those

areas that encountered deep fill materials over weathered bedrock (borings RW3-8 and C-6)

south of N.W. 50th Street, and those that encountered native soils over shallow weathered

bedrock (borings B-1, B-2, B-3 and B-4) north of N.W. 50th Street.

Description Approximate Depth to

Bottom of Stratum (feet) Material Encountered Consistency/Density

Stratum 1a 36.5 to 40

(borings RW3-8 and C-6)

Fill: Lean to fat clay with varying

amounts of sand1 N/A

Fill: Sand with varying amounts

of clay, silt and gravel1

Stratum 1b 2 to 13.5

(borings B-1 to B-4)

Sand with varying amounts of silt

and clay Loose to medium dense

Stratum 2 40 to 53.5

(borings RW3-8 and C-6)

Lean clay with varying amounts

of sand Stiff to very stiff

Stratum 3 Underlying stratum

Highly weathered to weathered

shale Soft to moderately hard

Highly weathered to weathered

sandstone

Poorly cemented to well

cemented 1. The existing fill may have been placed during the construction of the existing roadway. We are not

aware that compaction testing was performed during placement of the fill. The depth,

composition and compaction of the existing fill materials can vary greatly over relatively small

lateral and vertical distances. Because of the potential variability of fill, it will not be possible to

accurately predict the amount of fill that may need to be removed and replaced to develop

suitable support for the proposed improvements until s ite grading is underway. The depth and

composition of the fill, observed at the discrete boring locations, should only be used for

estimating purposes.

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

on the boring logs in Appendix A and on test report forms in Appendix B.



3.2 Groundwater

The borings were monitored while drilling, immediately after completing the drilling activities

and at least 24 hours after boring completion for the presence and level of groundwater. At

these times, groundwater was observed at the following depths:

Boring

Number

While Drilling Immediately After

Drilling

24+ Hour Water Level

After Drilling

Depth (ft.) Elevation

(ft.) Depth (ft.)

Elevation

(ft.) Depth (ft.)

Elevation

(ft.)

RW3-8 15 1119.5 17 1117.5 14 1120.5

C-6 Not

measured

Not

measured

Not

measured

Not

measured

Not

measured

Not

measured

B-1 1 1122.5 3 1120.5 13.5 1110.0

B-2 Not

encountered

Not

measured

Not

encountered

Not

measured 7 1132.5

B-3 Not

encountered

Not

measured

Not

encountered

Not

measured 3.5 1146.0

B-4 Not

encountered

Not

measured

Not

encountered

Not

measured 2 1142.5

To obtain more accurate groundwater level information, longer observations in a monitoring

well or piezometer that is sealed from the influence of surface water would be needed.

Fluctuations in groundwater levels can occur due to seasonal variations in the amount of

rainfall, runoff, altered natural drainage paths, and other factors not evident at the time the

borings were advanced. Consequently, the designer and contractor should be aware of this

possibility while designing and constructing this project.

4.0 ANALYSIS AND RECOMMENDATIONS

Based on the results of our exploration, the following geotechnical considerations were

identified:

Boring RW3-8: Sta. 271+75 to Sta. 273+50 - This boring indicates the presence of fill

extending to a depth of about 36.5 feet below existing ground. Based on the

information provided, it appears that the wall may bear on existing fill. Global stability

and bearing capacity analysis indicate relatively long reinforcement lengths when the

groundwater is considered at the base of the proposed retaining wall within the fill.



Boring C-6: Sta. 273+50 to Sta. 275+50 - Based on the retaining wall profile provided

by Leidos Engineering, Inc., the wall will extend through the fill, and will apparently

bear on the native lean clay.

Borings B-1, B-2 and B-3: Sta. 275+50 to Sta. 281+00 - The wall will extend through

the native soils, and will apparently bear on the weathered sandstone or highly

weathered shale/sandstone.

Boring B-4: Sta. 281+00 to Sta. 282+50 - The wall will extend through the native soil,

and will apparently bear on the weathered sandstone.

Due to the uncertainty of the existing fill, we believe that the fill with debris encountered

in boring RW3-8 could be present at other locations along the wall alignment.

Undercut and replacement of the fill with debris will be required in order to reduce

reinforcement lengths and expected differential settlement within the wall alignment.

We understand that the wall will ultimately be designed using the AASHTO Load and

Resistance Factor Design (LFRD) method. Recommended design parameters and the

results of our preliminary analyses using these values are provided in the following sections

of this report.

4.1 Recommended Geotechnical Engineering Design Parameters

In our analyses, we considered the soils outside the reinforced zone would partially consist of

existing overburden soils/rock and fill materials similar to the on-site soils/rock encountered in

the soil test borings. We also assumed that the backfill used within the reinforcement zone will

consist of properly compacted ODOT Type “A” aggregate base material or backfill meeting

current AASHTO and ODOT Standards for MSE retaining walls. Based on our analyses of the

laboratory tests performed for this project and our experience with similar soils, we recommend

the following geotechnical design parameters be used for analysis and design of the wall per

AASHTO LRFD Bridge Design Specification, 5th Edition, 2010.

RECOMMENDED GEOTECHNICAL PARAMETERS FOR MSE WALL DESIGN

Material

Type

Total Unit

Weight

(pcf)1

Effective Stress (Drained)

Parameters1

c′, psf ′, degrees

Reinforced Zone

(ODOT Type “A”) 125 N/A2 34

Alternate 110 N/A 34



RECOMMENDED GEOTECHNICAL PARAMETERS FOR MSE WALL DESIGN

Material

Type

Total Unit

Weight

(pcf)1

Effective Stress (Drained)

Parameters1

c′, psf ′, degrees

Reinforced Zone

(ASTM C-33 #57 Stone)

Retained/Foundation Zone

(Fill: Lean clay or clayey

sand) (near RW3-8 & C-6)3

120 50 26

Foundation Zone

(lean clay) (near C-6)3 120 50 26

Foundation Zone

(Weathered Sandstone) (B-1

to B-4)

125 0 36

1. The geotechnical parameters provided for the foundation soil are based on average correlated

values. 2. C=2000 psf used for global analysis to represent grid strength and force potential failure planes

outside of the reinforced zone. 3. Due to the presence of fill near the bearing level at borings RW3-8 and C-6, we recommend

overexcavating the subgrade within the proposed retaining wall areas to a depth of about 3 feet

below the retaining wall foundation. The overexcavation should extend laterally a minimum of 5

feet beyond the front of the retaining wall toe to a minimum distance behind the wall facing

equal to the width of the reinforced zone. The overexcavation should be backfilled to the

foundation base elevation with approved ODOT Type “A” structural fill placed in lifts of 9 inches

or less in loose thickness and should be compacted to at least 98 percent of the material’s

maximum standard Proctor dry density (AASHTO T-99) within 2 percent of its optimum value.

Based on the subsurface conditions encountered in the soil test borings, listed below are the

resistance and load factors based on AASHTO’s LRFD Bridge Design Specification, 5th Edition,

2010 that should be used by the retaining wall designer in the design of the retaining wall.

Load Factor for vertical earth pressure, EV, from Table 3.4.1-2 and Figure C11.5.5-2:

Sliding and Eccentricity p-EV = 1.00

Bearing Capacity p-EV = 1.35

Load Factor for live load surcharge, LS, from Table 3.4.1-2 and Figure C11.5.5-3b:

Bearing Capacity, Sliding and Eccentricity p-EV = 1.75



Load factor for active earth pressure, EH, from Table 3.4.1-2 and Figure C11.5.5-2:

p-EH = 1.50

Resistance factor for shear resistance along common interfaces from table 10.5.5.2.2 -1:

Reinforced Soil and Foundation = 0.9

Resistance factor for bearing capacity of a shallow foundation from table 10.5.5.2.2-1:

b = 0.45

Please note that we have determined reinforcement lengths for the MSE wall based on our

experience with MSE wall design and the parameters listed in the report. Actual design

embedment lengths in the contractor supplied design could vary from those used in our

analyses.

4.2 Retaining Wall Stability Analyses

Based on the plans, profiles, and cross sections provided by Leidos Engineering, Inc., we have

analyzed four different cross sections of the anticipated design profile of the retaining wall. The

cross sections were taken at stations 273+50, 274+50, 278+00 and 282+00. The maximum

design wall height will be up to about 35 feet. We understand that the retaining wall contractor

will perform internal and external stability analyses as part of the contractor supplied design of

the wall.

Our engineering analyses of the MSE wall has considered the following:

Foundation bearing capacity (with water level at the base of the foundation)

Settlement of the reinforced zone and differential settlement along the wall fascia

Direct sliding at the base of the reinforced zone

Horizontal grade at the toe of the proposed wall

4H:1V and 3H:1V grade at the back of the proposed wall

Minimum wall embedment of 3 feet

Global stability of the reinforced zone for both circular and horizontal block slip

surfaces, considering the reinforced zone to act as a rigid block

Reinforcement will consist of extensible geogrid

4.2.1 Foundation Bearing Capacity

The factored bearing resistance qR was evaluated using the following equation, which is

dependent on various soil properties and the design grid length.



qR = b qn (Equation AASHTO 10.6.3.1.1-1)

where: b = resistance factor

qn = nominal bearing resistance, which is defined as

qn = c Ncm + 0.5 B Nm Cw

where: c = cohesion

= unit weight

Ncm and N = dimensionless bearing capacity coefficients

B = total length of reinforcement

Cw = correction factors to account for the location of groundwater table

Based on the subsurface conditions encountered in the soil test borings and the proposed wall

geometry, the reinforcement grid lengths required varied from 11 to 45 feet (about 73 to 130

percent) in order to satisfy the LRFD Capacity to Demand Ratio (CDR). It is important to note

that for our analyses, we have considered that the ground water level will affect the ultimate

bearing capacity of the foundation soils. This assumption was made based on the 24 hour

water level readings and the geometry of the analyses. We also assumed that the wall near

boring RW3-8 will bear on approximately 5 feet of the remaining existing fill.

Based on the subsurface conditions, the retaining wall foundation can be analyzed using the

geotechnical design parameters presented in the Recommended Geotechnical Design

Parameters section of this report.

4.2.2 Settlement of Reinforced Zone

The wall settlement will depend upon the variations within the subsurface soil profile, the

structural loading conditions and the quality of the past and future earthwork operations.

Because of the variations associated with these parameters, Terracon cannot accurately

estimate settlements under all design scenarios. Assuming that the foundation bearing

conditions are similar to our subsurface data beneath all sections of the wall, it is our opinion

that the maximum total settlement experienced along the retaining wall will be less than 1

inch with maximum differential settlements not expected to exceed a slope of 1:200. These

values should be evaluated by the wall designer/manufacturer to confirm that the wall will be

able to tolerate this magnitude of total and differential settlement.

4.2.3 Direct Sliding

Our analyses indicate that with reinforcement lengths required to meet bearing capacity and

global stability requirements (on the order of 73 to 130 percent of the wall height) have a

CDR against direct sliding at the foundation equal to or greater than 1.0. Sliding may control

the design where the bearing surface consists of bedrock (shale or sandstone) support,



such as near borings B-1, B-2, B-3 and B-4. The factored resistance against failure by

sliding was determined using the following equation.

RR = R (Equation AASHTO 10.6.3.4-1)

where: = resistance factor for shear resistance between soil and foundation

R = nominal sliding resistance between soil and foundation

Based on the subsurface conditions, the wall designer should use the geotechnical design

parameters presented in the Recommended Geotechnical Design Parameters section of

this report when analyzing the external sliding resistance.

4.2.4 Global Stability of Reinforced Zone

We have performed global stability analyses for conceptual wall sections at borings RW3-8, C-

6, B-2 and B-4. Drained soil, foundation, and backfill geotechnical parameters were used in

our analyses. A resistance factor, , of 0.65, as outlined in section 11.6.2.3 of AASHTO’s

LRFD Bridge design Specification, 5 th Edition, 2010 was applied when analyzing the global

stability. Circular failures were analyzed using the modified Bishop method and sliding block

failures were analyzed using the modified Janbu method. All global stability analyses indicated

a CDR of 1.0 or greater.

We constrained the analysis of sliding block slip surfaces to the interface between the

reinforced zone and upper portion of the foundation soils by limiting shear surface development

in the reinforced zone. Our analysis focused on developing the minimum reinforced zone that

would satisfy a minimum global stability CDR of 1.0.

The stability analyses were performed on wall sections with reinforced zone length-to-height

ratio (i.e., the ratio of length of the reinforced zone to total wall height) of 0.7 to 1.3 as

determined to meet bearing capacity or sliding requirements. If the wall geometry is changed

(deeper penetration, shorter grids, etc), then additional global stability analyses should be

performed to confirm that the CDR is greater than 1.0.

Please note that the preceding discussion related so external global stability and not compound

stability of the retaining wall. Compound stability should be considered in the design analysis

conducted by the wall design engineer.

4.3 Global Stability of Temporary Excavation Slopes

Based on the drawings provided by Leidos Engineering, Inc., it is anticipated that up to 35 feet

of cut will be required for constructing the retaining wall. A slope stability analysis was



conducted for a typical section for temporary construction excavations. We have assumed no

surcharge in our analysis for these excavations.

A resistance factor, , of 0.75, as outlined in section 11.6.2.3 of AASHTO’s LRFD Bridge

design Specification, 5th Edition, 2010 was applied when analyzing the global stability for

maximum temporary excavation slopes.

Excavations deeper than 4 feet should meet all OSHA and other applicable safety

regulations.

Slopes for temporary excavations for subsurface conditions similar to those encountered at this

project should be constructed at 3H:1V or flatter. In areas where weathered bedrock is

encountered, the slopes for temporary excavation on weathered bedrock could be steepened

to 2H:1V.

We anticipate that excavations for the retaining wall may extend into weathered bedrock.

Rock formations that have standard penetration test results of 4 or more inches per 50

blows can usually be excavated with heavy excavation equipment equipped with ripping

teeth. Rock formations that have standard penetration test results of 3 inches or less per 50

blows usually require either pneumatic equipment or blasting for rock break-up and removal.

However, variations in hardness of rock can occur with depth and distance from the borings.

4.4 Wall Drainage Recommendations

Care should be taken in the design and during construction to develop and maintain rapid,

positive drainage away from the retaining wall area. Water should not be allowed to pond

adjacent to either the upslope or downslope sides of the retaining wall. We recommend that

drainage swales with sufficient gradients be constructed along both the upslope and downslope

sides of the wall to direct surface water away from the wall. Proper surface drainage is needed

to prevent water from flowing over the face of the wall and saturating either the fill behind the

wall or the subgrade soils at the base of the wall.

If Oklahoma Department of Transportation (ODOT) Type “A” aggregate base material is

used to construct the reinforced zone, we recommend that a backslope drain, comprised of

a geocomposite drainage blanket, such as Miradrain, be attached to the face of the cut

backslope and extend down to a collector drain pipe placed along the bottom of the

reinforced zone at the base of the cut slope. The collector drain should consist of a

perforated PVC pipe that is placed in free-draining aggregate such as ASTM No. 57 stone,

with the stone wrapped in a geotextile filter fabric. The collector drain should be sloped to

drain out beyond one or both ends of the retaining wall. The geocomposite drainage blanket

should be cut off at a depth of 2 feet below the finished ground surface at the back of the

reinforced backfill zone to allow a minimum cover of 2 feet of compacted clayey soil over the

drain to prevent the infiltration of surface water into the backslope drain.



Alternatively, select drainable aggregate fill material consisting of crushed No. 57 stone could

be imported to construct the entire reinforced zone. If the crushed No. 57 stone is used to

construct the reinforced backfill zone, we recommend that a geotextile filter fabric, such as

Mirafi 140N be placed between the face of the retained soil and the reinforced backfill zone to

prevent the migration of fines from the native soils or proposed fill into the free-draining No. 57

stone.

4.5 Construction Considerations

The construction specifications should provide the backfill material specifications and design

strength parameters that are required for the different fill zones so that unsuitable materials

are not used in the reinforced backfill zone during construction.

We recommend that any fill with debris encountered at the time of construction be removed

and replaced with ODOT Type “A” structural fill.

Any overexcavations for compacted backfill placement below the retaining wall should

extend laterally a minimum of 5 feet beyond the front of the retaining wall (or edge of the

embankment) toe to a minimum distance behind the wall facing equal to the width of the

reinforced zone. The overexcavation should then be backfilled to the foundation base

elevation with approved ODOT Type “A” structural fill placed in lifts of 9 inches or less in

loose thickness and compacted to at least 98 percent of the material's maximum standard

Proctor dry density (ASTM D-698) at a moisture content between 2 percent below to 2

percent above the material’s optimum moisture content.

Prior to starting construction of the MSE wall, fill material proposed to be used in

constructing the reinforced zone for the wall should be sampled and tested in the laboratory

to confirm that the engineering properties of the backfill satisfy the specified properties used

in design. Observation and field testing during construction of the MSE wall by qualified

geotechnical personnel is also recommended.

We anticipate that excavations for the retaining wall will extend into weathered bedrock.

Rock formations that have standard penetration test results of 4 or more inches per 50

blows can usually be excavated with heavy excavation equipment equipped with ripping

teeth. Rock formations that have standard penetration test results of 3 inches or less per 50

blows usually require either pneumatic equipment or blasting to remove. However,

variations in hardness of rock can occur with depth and distance from the borings.

Based on the groundwater conditions encountered during our subsurface exploration,

excavations for the retaining wall may encounter groundwater. Therefore, the contractor

should anticipate dewatering will be required during the construction of the walls.



5.0 GENERAL COMMENTS

Terracon should be retained to review the final design plans and specifications so

comments can be made regarding interpretation and implementation of our geotechnical

recommendations in the design and specifications. Terracon also should be retained to

provide observation and testing services during grading, excavation, wall construction and

other earth-related construction phases of the project.

The analysis and recommendations presented in this report are based upon the data

obtained from the borings performed at the indicated locations and from other information

discussed in this report. This report does not reflect variations that may occur between

borings, 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. If variations appear, we should be immediately notified so that further

evaluation and supplemental recommendations can be provided.

The 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 studies should be

undertaken.

This report has been prepared for the exclusive use of our client for speci fic application to

the project discussed and has been prepared in accordance with generally accepted

geotechnical engineering practices. No warranties, either express or implied, are intended

or made. Site safety, excavation support, and dewatering requirements are the

responsibility of others. In the event that changes in the nature, design, or location of the

project as outlined in this report are planned, the conclusions and recommendations

contained in this report shall not be considered valid unless Terracon reviews the changes

and either verifies or modifies the conclusions of this report in writing.

APPENDIX A

FIELD EXPLORATION


Responsive ■ Resourceful ■ Reliable Exhibit A-2

Field Exploration Description

A total of four additional test borings were drilled at the site on April 2, 2014. The borings were

drilled to depths ranging from approximately 10 to 15 feet below the ground surface at the

approximate locations shown on the attached Boring Location Diagram, Exhibit A-1. Subsurface

information collected from borings RW3-8 and C-6 provided in our geotechnical report No’s

03115012 dated 8/30/2011 and 03115101 dated 4/15/2011 was also used in developing our

recommendations.

Terracon personnel located the borings in the field by taping distances and estimating right

angles based on information from the site plan provided by Leidos Engineering, LLC. The boring

locations should be considered accurate only to the degree implied by the methods used to

define them. Terracon determined the approximate ground surface elevations at the borings

using an engineer’s level. These elevations were referenced to the benchmark shown in the

following table. Based on the benchmark, the ground surface elevations at the boring locations

ranged from 1123.3 to 1149.7 feet. The elevations shown on the logs have been rounded to the

nearest 0.1 foot. The boring locations and elevations should be considered accurate only to the

degree implied by the methods used to define them.

Bench Mark Description Northing/Easting Elevation, ft.

13 “V” T/C by F.H. @ N.W.

50th & Sewell 190386.14 / 2112582.36 1142.57

An all-terrain truck mounted, rotary drill rig equipped with continuous flight augers was used to

advance the boreholes. Representative samples were obtained by the split -barrel sampling

procedures.

The split-barrel sampling procedure uses a standard 2-inch O.D. split-barrel sampling spoon

that is driven into the bottom of the boring with a 140-pound drive hammer falling 30 inches.

The number of blows required to advance the sampling spoon the last 12 inches, or less, of a

typical 18-inch sampling interval or portion thereof, is recorded as the standard penetration

resistance value, N. The N value is used to estimate the in-situ relative density of cohesionless

soils and, to a lesser degree of accuracy, the consistency of cohesive soils and the hardness of

sedimentary bedrock. The sampling depths, penetration distances, and the N values are

reported on the boring logs. The samples were tagged for identification, sealed to reduce

moisture loss and returned to the laboratory for further examination, testing and classification.

An automatic Standard Penetration Test (SPT) drive hammer was used to advance the split -

barrel sampler. The automatic drive hammer achieves a greater mechanical efficiency when

compared to a conventional safety drive hammer operated with a cathead and rope. We

considered this higher efficiency in our interpretation and analysis of the subsurface information

provided with this report.


Responsive ■ Resourceful ■ Reliable Exhibit A-2

The drill crew prepared field logs as part of the dr illing operations. These boring logs included

visual classifications of the materials encountered during drilling and the driller’s interpretation of

the subsurface conditions between samples. The final boring logs included with this report

represent the engineer’s interpretation of the field logs and include modifications based on

observations and tests of the samples in the laboratory.

As required by the Oklahoma Water Resources Board, any borings deeper than 20 feet, or

borings that encounter groundwater or contaminated materials must be grouted or plugged in

accordance with Oklahoma State statutes. One boring log must also be submitted to the

Oklahoma Water Resources Board for each 10 acres of project site area. Terracon grouted the

borings and submitted a log in order to comply with the Oklahoma Water Resources Board

requirements.

APPENDIX B

LABORATORY TESTING


Responsive ■ Resourceful ■ Reliable Exhibit B-1

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 Appendix C. Samples of bedrock were

classified in accordance with the general notes for Sedimentary Rock Classification. 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 and bedrock 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 and bedrock samples obtained from the site were tested for the following

engineering properties:

In-situ Water Content

Atterberg Limits

Sieve Analysis

APPENDIX C

SUPPORTING DOCUMENTS

01 - 1011 - 30

> 30

RELATIVE PROPORTIONS OF FINES

Descriptive Term(s)of other constituents

Percent ofDry Weight

Hand Penetrometer

Torvane

Standard PenetrationTest (blows per foot)

Photo-Ionization Detector

Organic Vapor Analyzer

Texas Cone Penetrometer

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

Exhibit C-1

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 5 - 9

30 - 50

WA

TE

R L

EV

EL

Auger

Shelby Tube

Grab Sample

FIE

LD

TE

ST

S

DESCRIPTION OF SYMBOLS AND ABBREVIATIONS

Descriptive Term(Density)

Non-plasticLowMediumHigh

BouldersCobblesGravelSandSilt or Clay

10 - 18

> 50 15 - 30 19 - 42

> 30 > 42

_

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

> 8,000

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

8 - 15

Split Spoon

Rock Core

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

Very Loose 0 - 3 0 - 6 Very Soft

7 - 18 Soft

10 - 29 19 - 58

59 - 98 Stiff

less than 500

500 to 1,000

1,000 to 2,000

2,000 to 4,000

4,000 to 8,000> 99

LOCATION AND ELEVATION NOTES

SA

MP

LIN

G

< 55 - 12> 12

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 Unconfined CompressiveStrength, Qu, psf

4 - 8

GENERAL NOTES

Texas Cone

(HP)

(T)

(b/f)

(PID)

(OVA)

(TCP)

Pressure Meter

Exhibit C-2

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 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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Exhibit C-3

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Geotechnical Engineering Report...Geotechnical Engineering Report Proposed Retaining Wall 44ARW-1 Oklahoma City, Oklahoma May 8, 2014 Terracon Project No. 03145071 Responsive Resourceful

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