Attachment- 29 Bonham VA - Geotech Rpt 3-30-16-For Soil.pdf

ETTL Engineers & Consultants Inc.

GEOTECHNICALMATERIALS ENVIRONMENTAL DRILLING LANDFILLS

Main Office: 1717 East Erwin St. Tyler, Texas 75702 Phone: 903-595-4421 Fax: 903-595-6113

Longview Branch: 707 West Cotton St. Longview, Texas 75604 Phone: 903-758-0915 Fax: 903-758-8245

Texarkana Branch: 210 Breech St. Texarkana, Arkansas 71854 Phone: 870-722-0013 Fax: 870-216-2413

Arlington Branch: 2000 E. Randal Mill Rd. Suite 613 Arlington, Texas Phone: 817-962-0048 Fax: 817-962-0025 w w w . e t t l i n c . c o m

August 17, 2015

Michele Williams

HFS Company

8718 Botts Lane

San Antonio, Texas 78217

SUBJECT: Sam Rayburn Memorial Veterans Center – Parking Lot Upgrades

Bonham, Texas

Geotechnical Investigation

ETTL Job No. G 4393-15

Dear Mrs. Williams:

Submitted herein is the report summarizing the results of a geotechnical investigation conducted at the site of the above referenced project.

If you have any questions concerning this report, or if we can be of further assistance during construction, please contact us. We are available to perform any construction materials testing and inspection services that you may require. Thank you for the opportunity to be of service.

Sincerely, ETTL Engineers & Consultants Inc.

Texas Registered Engineering Firm #F3208

Owen B. Sanderson, P.E. C. Brandon Quinn, P.E., P.G.

Project Manager Vice President

Manager of Engineering Services

08/17/2015

Distribution: (PDF) HFS Company

08/17/2015

Geotechnical Investigation

Sam Rayburn Memorial Veterans Center

Parking Lot Upgrades

Bonham, Texas

Submitted to

HFS Company

San Antonio, Texas

Prepared by

ETTL Engineers & Consultants Inc.

Tyler, Texas

August, 2015

ETTL Engineers & Consultants Sam Rayburn Memorial Veterans Center

Parking Lot Upgrades

Geotechnical Investigation ETTL Job No. G 4393-15

Page i

EXECUTIVE SUMMARY

This Executive Summary is provided as a brief synopsis of the specific recommendations and design criteria provided in the attached report. It is not intended as a substitute for a thorough reading of the report in its entirety.

Project Description

The project will consist of the reconstruction and replacement of an existing 55,400 square foot parking lot near Buildings 9, 10, 11 and 12. The proposed pavement sections will be either asphalt or concrete paving.

Site Description

The project site is currently a concrete paved parking lot with drives overlaid with asphalt surfacing located between buildings 9, 10, and 11. The topography is relatively flat with slight slope to existing storm drains. The site contains numerous underground utilities.

Depth & Number of Borings

4 – 5’ deep in the existing parking and drives

Pavement Section & Soils Encountered

The current pavement section varies slightly between borings but typically is:

1.5 inches of HMAC (surface)

5 inches of Concrete

4 to 7 inches of Flex Base

Stiff Fat Clay (CH), (subgrade)

The Atterberg Plasticity Indices of the tested subgrade soils ranges from 37 to 44. Based on preliminary laboratory testing the surficial soils in the parking areas contain sulfate concentrations less than 3,000 ppm.

Groundwater Depth

No seepage was encountered during the drilling activities and following the completion of drilling the open bore holes where observed to be dry. The phreatic surface is predicted to be deeper than 5 feet below existing pavement surface at the time of drilling.

Pavement Sections Actual traffic counts for the proposed parking and drives are unknown at this time. Recommended pavement sections for light, medium and heavy duty traffic are included. Estimated allowable traffic loads, based on the AASHTO Guide for Design of Pavement Structures 1993, for each section are provided in the report.

Geotechnical Investigation ETTL Job No. G 4393-15

Page ii

Table 1 – Pavement Options – Light Duty

Type Base/Surface Thickness Subgrade

Preparation1

Flexible

HMAC

2” Surface (Type D)

6” Crushed Stone Base

8” Lime Treated1

Concrete 5” No Base Required 8” Lime Treated2

Table 2 – Pavement Options – Medium Duty

Type Base/Surface Thickness Subgrade

Preparation1

Flexible

HMAC

3” Surface (Type C or D)

8” Crushed Stone Base

8” Lime Treated1

Concrete 6” No Base Required 8” Lime Treated2

Table 3 – Pavement Options – Heavy Duty

Type Base/Surface Thickness Subgrade

Preparation1

Flexible

HMAC

2” Surface (Type C or D)

7” Crushed Stone Base & 2.5” HMAC

Base 8” Lime Treated1

Concrete 7” No Base Required 8” Lime Treated2

Notes:

1) Tensar® TX7® Geogrid placed on subgrade may be substituted for lime treatment of subgrade.

2) Increase concrete thickness by 1” in lieu of lime treated subgrade.

Construction Considerations The subgrade soils may become unstable when wet necessitating removal and replacement or remediation to facilitate construction.

Geotechnical Investigation ETTL Job No. G 4393-15

Page iii

TABLE OF CONTENTS

EXECUTIVE SUMMARY ..................................................................................................................i

1.0 INTRODUCTION

2.0 PROJECT DESCRIPTION

3.0 SITE DESCRIPTION

4.0 FOUNDATION SOIL STRATIGRAPHY AND PROPERTIES

4.1 Site Geology

4.2 Existing Pavement Section

5.0 GROUNDWATER OBSERVATIONS

6.0 PAVEMENT DESIGN

6.1 Design Parameters

6.1.1 Traffic

6.1.2 Pavement Design Life

6.1.3 Desired Reliability Level

6.1.5 Roadbed Soil Resilient Modulus

6.1.6 Subbase/Treated Subgrade

6.1.7 Stability of Finished Subbase

6.1.8 Flexible Base

6.2 Asphalt and Concrete Pavement Design

6.2.1 AASHTO Flexible Pavement Design Parameters

6.2.2 AASHTO Concrete Pavement Design Parameters

7.0 GENERAL CONSTRUCTION CONSIDERATIONS

8.0 LIMITATIONS

APPENDIX A - Field Investigation

Plate I: Plan of Borings

Plate II: Utility Designation Field Sketch

Log of Borings with Laboratory Test Data

Key to Soil Classification & Symbols

APPENDIX B - Laboratory Testing

APPENDIX C

SpectraPave4 Pro Report

Geotechnical Investigation ETTL Job No. G 4393-15

1.0 INTRODUCTION

This study was performed at the request and authorization to proceed granted by Michele Torres with HFS Company in San Antonio, Texas in accordance with the MOU signed and dated by

Brandon Quinn, P.E. of ETTL Engineers & Consultants, Inc. on June 25, 2015.

The purpose of this investigation was to define and evaluate the general subsurface conditions between buildings 9, 10 and 11 at the Sam Rayburn Memorial Veterans Center in Bonham, Texas.

Specifically, the study was planned to determine the following:

Subsurface stratigraphy within the limits of exploratory borings;

Classification, strength and expansive properties of the subgrade soils;

Pavement design recommendations (AASHTO) and

Construction related problems that may be anticipated by the investigation.

To determine this information a variety of tests were performed on the soil samples. The scope of testing for this report comprised Standard Penetration, Atterberg liquid and plastic limits, Percentage of Fines Passing the No. 200 sieve, Natural Moisture Content, and Soluble Sulfates.

The conclusions and recommendations that follow are based on limited information regarding site grading. ETTL located the borings on the ground based on a site plan provided by others. (ETTL did not confirm by survey that the locations indicated on the attached Plan of Borings accurately reflect the location on the ground). This information should be verified prior to design. Should any portion of it prove incorrect, this firm should be notified in order to assess the need for revisions to this report.

2.0 PROJECT DESCRIPTION

The project will consist of the reconstruction and replacement of an existing 55,400 square foot parking lot near Buildings 9, 10, 11 and 12. The proposed pavement sections will be either asphalt or concrete paving.

3.0 SITE DESCRIPTION

The project site is currently a concrete paved parking lot with drives overlaid with asphalt surfacing located between buildings 9, 10, and 11. The topography is relatively flat with slight slopes to existing storm drains. The site contains numerous underground utilities. Prior to the drilling activities a utility designation ASCE quality level B was conducted by CobbFendley. The field sketch of the findings is provided in APPENDIX A.

Geotechnical Investigation ETTL Job No. G 4393-15

4.0 FOUNDATION SOIL STRATIGRAPHY AND PROPERTIES

4.1 Site Geology

The Bonham Marl Formation outcrops the project site. This Upper Cretaceous formation is mapped in a north-south belt across northeast Texas in Fannin County, TX. It overlies the Eagle Ford

Formation; overlain by Blossom Sand. The Bonham Marl formation is described as a glauconitic, calcareous, sandy marl and clay. It is greenish gray in color that weathers to yellowish to light gray.

The formation thickness is 375 to 530 ft.

For more information please refer to the National Geologic Map Database and the Geologic Atlas of

Texas.

http://ngmdb.usgs.gov/Geolex http://www.twdb.state.tx.us/groundwater/aquifer/GAT/

4.2 Existing Pavement Section

The current pavement section varies slightly between borings but typically is:

1 to 2 inches of HMAC (surface)

4 to 6 inches of Concrete

3 to 7 inches of Flex Base

Stiff Fat Clay (CH), (subgrade)

The Atterberg Plasticity Indices of the tested subgrade soils ranges from 37 to 44. Based on preliminary laboratory testing the surficial soils in the parking areas contain sulfate concentrations less than 3,000 ppm.

5.0 GROUNDWATER OBSERVATIONS

No seepage was encountered during the drilling activities and sometime following the completion of drilling the open bore holes where observed to be dry. The phreatic surface is predicted to be deeper than 5 feet below existing pavement surface.

Data regarding groundwater level was obtained by observations in open boreholes. At best this provides only an approximation of the phreatic surface at the time of drilling. The phreatic surface that should be considered for the design of this project may vary significantly from that which was observed in the borings due to the following factors:

The characteristics of the soil profile may have prevented the water level in the boring from rising to the phreatic level during the time period of observation

A given boring may not intercept groundwater bearing zones (i.e. the groundwater is perched or travels in seams or fissures that are not continuous over the entire site)

Groundwater may only be perched in pockets above local aquacludes, but the distribution of borings is not generally adequate to confirm this with a high level of certainty

Groundwater level varies seasonally and with rainfall

Geotechnical Investigation ETTL Job No. G 4393-15

Rotary wash drilling methods introduce fluid into the boring that often makes it impossible to distinguish between groundwater and drilling fluid

If the designer believes that the level of groundwater could significantly impact the project, then

ETTL should be contacted to develop a plan for piezometer installation and monitoring to more accurately assess the groundwater levels at the site.

6.0 PAVEMENT DESIGN

The proposed general pavement section is designed using the AASHTO Guide for Design of

Pavement Structures 1993. This design process requires that certain parameters be determined, each of which can have a significant effect on the final pavement thickness. Listed below are the parameters used in this case. The rigid pavement sections were evaluated using the nomographs and equations provided in the 1993 AASHTO Guide. SpectraPave4 Pro Software for Subgrade

Stabilization and Pavement Optimization, Version 4.6.1, January 2014 developed by Tensar

International Corporation was used to evaluate the flexible pavement sections below. Software printouts of the HMAC design sections are in the Appendix C.

6.1 Design Parameters

6.1.1 Traffic

Traffic for the site is unknown at this time. For this project, multiple proposed pavement sections were considered and an estimate of the allowable traffic load for each section was determined. The allowable equivalent 18 kip single axle loads (ESAL’s) were then converted to an estimated Average

Daily Traffic (ADT). This allowable ADT is assumed to consist of about 98% passenger cars and

2% loaded 18 wheel trucks. The asphaltic designs are for a 20 year design life while the rigid

(concrete) designs are for a 30 year design life.

6.1.2 Pavement Design Life

This is the expected time the pavement will remain in a satisfactory condition, given proper maintenance. Typical design life is 20 years for asphaltic pavement sections and 30 years for concrete sections.

6.1.3 Desired Reliability Level

This is the statistical probability that the pavement will last the entire design life. Reliabilities of 50 to

85 percent are normally used for local streets and parking areas and over 90% is used for highways.

We have provided pavement designs for 85 percent criteria.

6.1.4 Serviceability

The serviceability of a pavement is a rating of the physical characteristics such as roughness, cracking, patching, and rut depth. This is expressed as the present serviceability index (PSI) that ranges from a value of 5 for a perfect road to 0 for an impassible road. The AASHTO pavement design is based on the change in the PSI. The initial PSI for the rigid design in this report is 4.5 while for the flexible design 4.2 is assumed for the initial PSI. The terminal PSI is assumed to be

2.0. These values conform to the guidelines that TxDOT uses for pavement designs.

Geotechnical Investigation ETTL Job No. G 4393-15

6.1.5 Roadbed Soil Resilient Modulus

The resilient modulus is the material property used to characterize the roadbed soils for the pavement design. This modulus was predicted based on the soil types encountered at the site. It should be noted that Laboratory CBR values (use to predict the resilient modulus) were beyond the scope of this project. Based on the soils in the upper 2.5 feet, a design CBR of 2.5 was used for theses streets. This CBR value correlates to a modulus value of approximately 4,500 psi.

6.1.5.1 Pavement Subgrade Preparation

As a minimum, removed the existing pavement section and verify that areas disturbed by demolition activity, if any, are cut out and backfilled with properly compacted fill. The heaving effect can be reduced with good pavement drainage and maintenance. If this is not feasible, then future additional pavement maintenance will probably be necessary.

Cut to the proposed subgrade elevation as required. Exposed subgrade should be proof rolled prior to compaction or treatment in accordance with TxDOT Item 216 with the exception of roller size.

The use of a fully loaded dump truck is recommended. Areas which prove unstable should be cut out and replaced with select fill. In areas that are below finished subgrade elevation or which are to be lime treated, scarify the exposed subgrade to a depth of 8 inches, adjust the moisture content to within a range of optimum -1% to optimum +3%, and recompact to a minimum of 95% of the density as defined by ASTM D 698 (Standard Proctor). Lime treatment of subgrade that consists of native clay, or native clay fill is recommended as set forth below.

6.1.5.2 Fill Construction

Fill material to be used beneath areas to be paved may consist of any native soil and should be compacted to a minimum density of 95% ASTM D698 (standard proctor) at a moisture content within the range of optimum ±3% except for clay soils which should be placed at above optimum moisture contents. Due the potential presence of soils with relatively high PI’s (PI>20), lime treatment is recommended.

Prepare the subgrade in accordance with the recommendations discussed above. Sites that slope more than about 15% should be benched with 5-foot wide benches prior to placing fill.

Place subsequent lifts of fill in thin, loose layers not exceeding nine inches in thickness to the desired rough grade and compact to a minimum of 95% of the maximum density defined by ASTM D 698. Maintain moisture within a range of optimum ±3%.

Conduct in-place field density tests at a rate of 1 test per each 2,000 square feet of parking.

Density testing is essential to assure that the soil, which supports the structure, is properly placed.

Prevent excessive loss of moisture during construction.

Geotechnical Investigation ETTL Job No. G 4393-15

For select fill placed above the existing groundline, extend the lateral limits of the fill at least

5 feet beyond the perimeter of the construction area, transitioning back to the existing groundline on a 3:1(horizontal/vertical) slope.

Finished subgrade should be proof rolled prior to compaction in accordance with TxDOT Item 216 with the exception of roller size. The use of a fully loaded dump truck is recommended. Areas which prove unstable should be cut out and replaced with select fill.

6.1.6 Subbase/Treated Subgrade

Subbase consists of imported material or treated native material that lies below the base and above the subgrade. Due to the high PI of the native subgrade soils (PI>20) lime treatment is recommended. Lime treatment of the Subgrade soils can be eliminated if the top 18” of the subbase consist of a select fill material with the following properties: a PI <15, a liquid limit <35 and a percentage passing the #200 sieve <40%.

6.1.6.1 Lime Treated Subgrade

Lime treatment of subgrade should be in accordance with Item 260, "Lime Treatment for Materials

Used as Subgrade (Road Mixed)," Texas Department of Transportation Standard Specifications for

Construction of Highways, Streets and Bridges, 2004 Edition with the following exceptions:

Under article 260.4 (4), "Application," the rate of lime to be applied can be estimated as 40 pounds per square yard worked into the top 8 inches. The actual amount of lime to be used should be based on tests of lime soil mixtures conducted prior to treatment. Quicklime, if used, must be hydrated before mixing into the soil.

The modified subgrade should be compacted under article 260.4 (6) (b), "Density Control," except that it shall be compacted to 95% of Standard Proctor Density (ASTM D698) at a moisture content well above optimum to allow for the drying action of the lime.

Curing procedures should be strictly followed. Traffic on the treated subgrade should be kept to a minimum during curing.

Prior to use by significant traffic, the treated subgrade should be covered with base, concrete or some temporary wearing surface to avoid degradation.

6.1.6.2 Guidelines for the Treatment of Sulfate Rich Soils

All soils with sulfate contents less than 8,000 ppm may be lime stabilized, with little possibility of sulfate induced heave. However, sulfates in the project geology generally occur in veins that may or may not be intercepted by the procedures used to obtain samples for this study. Based on preliminary laboratory testing the surficial soils in the parking areas contain sulfate concentrations less than 3,000 ppm. Considering this fact, the standard procedure used by TxDOT is to prepare finished subgrade and then visually inspect and perform field tests for sulfate content prior to liming.

This allows obvious problem areas to be identified. The use of a field conductivity meter may also be used to identify problem areas.

Geotechnical Investigation ETTL Job No. G 4393-15

The following recommendations are given for treatment of soils with differing sulfate contents:

1. For sulfate contents less than 3,000 ppm (low risk), the lime stabilization may be according to TxDOT Specification Item 340 as modified, above.

2. For contents from 3,000 to 5,000 ppm (moderate risk), a mellowing period of at least 3 days is required. These areas should be processed at a minimum of 3% above optimum. Field distribution performed using a slurry is beneficial. The initial mixing and mellowing should be conducted at a moisture content 3 to 5% above the optimum moisture content defined by

Tex-113-E.

3. For areas where the sulfate content ranges from 5,000 to 8,000 ppm (moderate to high risk), similar procedures should be used as listed above, but the mellowing period should be increased to 6 days.

4. If sulfate content is above 8,000 ppm (high risk), the soil should be removed and replaced with common fill (low sulfate content) from cut areas and then lime stabilized.

In fill areas, the high sulfate soils may be mixed with low sulfate soils in order to dilute the final sulfate content to an acceptable level for use in the fills. It would be preferable to use the higher sulfate soils in the deeper fill zones (where stabilization is not necessary) and the lower sulfate soils in the upper portion of the fill (where stabilization will occur).

The mellowing period is especially beneficial for soils that may have high sulfate contents. If moderate to high percentages (3,000 to 8,000 ppm) of sulfates are found, the additional moisture will pre-swell the resulting mixture. If a significantly higher sulfate content is present and was not defined by preliminary testing, visible heaves will be an additional indicator of areas to be removed.

This is possible since the areas with very high sulfate contents are typically isolated in narrow seams. Visible gypsum crystals in the soil are also an indicator of high sulfate content.

6.1.6.3 Alternatives to Lime Treatment

For the flexible pavement option (only) placing a geogrid (Tensar® TriAx® Geogrid, no substitute) on the native subgrade prior to placing base material will serve as a substitute for lime treated subgrade. For the rigid pavement option (concrete) increase the recommended thickness by 1” where lime treatment is omitted.

6.1.7 Stability of Finished Subbase

The stability of the finished subbase should be verified by proof rolling (as specified above) prior to placing base material or surfacing. Unstable areas will need to be cut out and reworked.

6.1.8 Flexible Base

Crushed stone base should comply with Type A, Grade 2, Item 247 of the Texas Department of

Transportation (TxDOT) 2004 Standard Specifications for Construction of Highways, Streets and

Geotechnical Investigation ETTL Job No. G 4393-15

Bridges. Compaction of the stone base should be to a minimum of 95 percent of ASTM D 1557

(modified proctor) maximum density at optimum moisture ±3 percent.

6.2 Asphalt and Concrete Pavement Design

All sections below were evaluated using the assumptions for an AASHTO procedure as listed below.

The flexible pavement sections were evaluated using SpectraPave4 Pro Software for Subgrade

Stabilization and Pavement Optimization, Version 4.6.1, January 2014 developed by Tensar

International Corporation. The rigid pavement designs were evaluated using the nomographs and equations provided in the 1993 AASHTO Guide.

6.2.1 AASHTO Flexible Pavement Design Parameters

A summary of the selected AASHTO parameters and additional parameters needed for the asphalt design are as follows:

Design Traffic (20 year design life) Varies (see Table)

Reliability, R 85%

Standard Deviation, S 0.49

Design Serviceability Loss, Dp 4.2

Predicted California Bearing Ratio (CBR) of Roadbed Soil 2.0

HMAC surfacing (Type D) should comply with the requirements of Item 340 of the TxDOT

Specifications and should be compacted in lifts as necessary to a density in the range of 92% to

94% of the maximum theoretical density. Testing to verify compliance with the specifications is highly recommended to help assure optimal pavement life.

Table 6.1 – HMAC Pavement Options

Type Surface Base Subgrade1 Allowable ESAL’s (ADT)

Light Duty 2” (Type D) 6” Crushed Stone 8” Lime Treated1 27,000 (95)

Medium Duty 3” (Type D) 8” Crushed Stone 8” Lime Treated1 150,000 (500)

Heavy Duty 2” (Type D) 2.5” (Type B or C) / 7” Crushed Stone

8” Lime Treated1 380,000 (1,300)

Notes:

1) Tensar® TX7® Geogrid placed on subgrade may be substituted for lime treatment of subgrade.

6.2.2 AASHTO Concrete Pavement Design Parameters

The concrete pavement designs below are based on the design parameters given above in addition to other criteria listed below. The AASHTO design criteria needed for the design of a rigid pavement are as follows:

Design Traffic (30 year design life) Varies (see Table)

Reliability, R 85%

Design Serviceability Loss, Dp 2.5

Geotechnical Investigation ETTL Job No. G 4393-15

Predicted California Bearing Ratio of Roadbed Soil 2.5

Standard Deviation, So 0.39

Concrete Elastic Modulus 3.37 X 106

Concrete Modulus of Rupture 530 psi (3,500 psi concrete)

Effective Modulus of Subgrade Reaction 98 pci

Drainage Coefficient (good drainage) 0.94*

Load Transfer (dowelled, curb and gutter) 2.9

Loss of Support 1.0

* Good drainage (water drained away within one hour) assumed. If drainage is only fair (water stands for one day), the coefficient is reduced to 0.8 and required thicknesses given in the designs below should be increased by 0.5".

The performance of concrete pavement is dependent on many factors including weight and frequency of traffic, subgrade conditions, concrete quality (which itself is dependent on a host of factors), joint type and layout, jointing procedures, and numerous construction practices. A detailed discussion of all of these items is beyond the scope of this report. By way of general guidance, the following recommendations are offered:

Minimum concrete compressive strength of 3,500 psi at 28 days. The water/cement ratio should be 0.45 or less. The mix should contain 4% - 6% entrained air for durability.

Minimum pavement thickness of 5 inches.

Sawcut or preformed control joints at maximum spacing of 12 feet each way. Layout of joints should form basically square panels. Timing of the cutting of joints is critical to their performance and generally should be within 4 - 18 hours of concrete placement. Sealing of joints and cracks and maintenance of the seal are critical for satisfactory performance.

Adequate site drainage to prevent ponding on or near the pavement.

Cure concrete via use of liquid membrane curing compound.

Concrete quality should be controlled and jointing properly executed. Minimum reinforcement should consist of 6 x 6 – W2.9 x W2.9 welded wire fabric or No. 3 at 24 inches each way. Reinforcing should not be continuous through construction joints. For sawcut joints, discontinue reinforcing and place dowels at a maximum spacing of 30 feet when using welded wire fabric or 60 feet when using No. 3 bars.

All edges of pavement should be thickened to 9 inches (transitioning back to 5 inches over a minimum distance of 3 feet).

Allow a minimum of 7 days curing time before permitting traffic on the pavement.

Geotechnical Investigation ETTL Job No. G 4393-15

The reader is referred to the American Concrete Institute Publication No. ACI 330R, Guide for

Design and Construction of Concrete Parking Lots for more detailed information.

Table 6.2 – Rigid Pavement Options

Type Portland Cement

Concrete Pavement Subgrade1 Allowable

ESAL’s (ADT)

Light Duty 5” 8” Lime Treated1 110,000 (95)

Medium Duty 6” 8” Lime Treated1 310,000 (300)

Heavy Duty 7” 8” Lime Treated1 750,000 (750)

Notes:

1) Increase concrete thickness by 1” in lieu of lime treated subgrade.

7.0 GENERAL CONSTRUCTION CONSIDERATIONS

Some areas may become unstable when wet necessitating stabilization or removal and replacement to facilitate construction. The optimal approach is best determined during construction after visual inspection by a representative of ETTL.

The application of dry lime in an area surrounded by buildings (as is the case at this site) can create clouds of lime particulate in the air that settle out on surrounding objects. The application of a lime slurry as described herein can prevent this somewhat.

8.0 LIMITATIONS

Geotechnical design work is characterized by the presence of a calculated risk that soil and groundwater conditions may not have been fully revealed by the exploratory borings. This risk derives from the practical necessity of basing interpretations and design conclusions on a limited sampling of the subsoil stratigraphy at the project site. The number of borings and spacing is chosen in such a manner as to decrease the possibility of undiscovered anomalies, while considering the nature of loading, size and cost of the project. The recommendations given in this report are based upon the conditions that existed at the boring locations at the time they were drilled. The term

"existing groundline" or "existing subgrade" refers to the ground elevations and soil conditions at the time of our field operations.

It is conceivable that soil conditions throughout the site may vary from those observed in the exploratory borings. If such discontinuities do exist, they may not become evident until construction begins or possibly much later. Consequently, careful observations by the geotechnical engineer must be made of the construction as it progresses to help detect significant and obvious deviations of actual conditions throughout the project area from those inferred from the exploratory borings.

Should any conditions at variance with those noted in this report be encountered during

Geotechnical Investigation ETTL Job No. G 4393-15 construction, this office should be notified immediately so that further investigations and supplemental recommendations can be made.

Construction plans and specifications should be submitted to ETTL for review prior to issuance for construction to help verify that the recommendations of this report have been correctly understood and implemented.

This company is not responsible for the conclusions, opinions, or recommendations made by others based on the contents of this report. The recommendations made in this report are applicable only to the proposed scope of work as defined in SECTION 2.0 PROJECT DESCRIPTION and may not be used for any other work without the express written consent of ETTL Engineers. The purpose of this study is only as stated elsewhere herein and is not intended to comply with the requirements of

30 TAC 330 Subchapter T regarding testing to determine the presence of a landfill. Our professional services have been performed, our findings obtained, and our recommendations prepared in accordance with generally accepted geotechnical engineering principles and practices.

No warranties are either expressed or implied.

APPENDIX A

Field Operations

Subsurface conditions were defined by 4 sample core borings drilled to depths from 5 feet. ETTL personnel staked the boring locations based on a site plan provided by the client. The field boring logs were prepared as drilling and sampling progressed. The final boring logs are also included in the Appendix. Descriptive terms and symbols used on the logs are in accordance with the Unified

Soil Classification System (ASTM D 2487). A reference key is provided on the final page of this report.

A truck-mounted, GeoProbe® was used to advance the borings. Soils were sampled by means of a

3-inch O.D. by 24-inch long thick-walled Shelby Tube sampler. Using the GeoProbe® hydraulic pressure, the sampler was pushed smoothly into the bottom of the borehole. The consistency of these samples was measured in the field by a calibrated pocket penetrometer. These values, recorded in tons per square foot, are shown on the boring logs. Such samples were extruded in the field, logged, sealed to maintain in situ conditions, and packaged for transport to the laboratory.

All boreholes were backfilled with cuttings after collecting final groundwater readings. Samples obtained during our field studies and not consumed by laboratory testing procedures will be retained in our Tyler office free of charge for a period of 60 days. To arrange storage beyond this point in time, please contact the Tyler office.

CH

1" HMAC

5" Concrete

7" Flex Base

FAT CLAY(CH) very stiff; dark gray with light gray; moist; mottled

FAT CLAY(CH) very stiff; light gray with gray and light brown; moist; mottled

Bottom of Boring @ 5'

1 055 17 38 9726 P=4.0

P=2.8

P=4.0

P=3.2

LOG OF BORING B-1

PL F

R

E E

S W

E

LL

PI

7/28/15

SWELL

TEST

Perched:Est.:

Dry and open upon completion.

Qu (tsf)

P

LA

S T

IC

IT

Y

IN

D E

X

M

IN

U S

S

IE

V

E

P

LU

S

S

IE

V

E

P

LU

S

S

IE

V

E

PPR (tsf) Moisture Content

Plastic Limit

Natural Moisture Content and

Atterberg Limits

Liquid Limit

1.0 2.0 3.0 4.0

1.0 2.0 3.0 4.0

BLOW COUNT COMPRESSIVE

STRENGTH

Torvane (tsf)

20 40 60 80

D E

P T

H ft)

Water Level

S A

M P

LE

S USC

Measured:

W A

T E

R L

E V

E L

G E

O

LO

G

IC

U N

IT

Water Observations:

MAIN OFFICE

1717 East Erwin

Tyler, Texas 75702

(903) 595-4421

ETTL

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CONSULTANTS

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N T

DRILL RIG:

BORING TYPE:

F

IE

LD

S T

R E

N G

T H

D A

T A

DATE

SURFACE ELEVATION

ATTERBERG

LIMITS(%)

SIEVE

ANALYSIS

1 2 3 4

M O

IS

T

U R

E C

O N

T E

N T

20 40 60 80

C O

M P

R E

S S

IV

E

S T

R E

N G

T H ts f)

M O

IS

T

U R

E C

O N

T E

N T

LI

Q

U

ID

L

IM

IT

P

LA

S T

IC

L

IM

IT

MATERIAL DESCRIPTION

PROJECT:

PROJECT NO.:

LL

GPS Coordinates:

Key to Abbrevations: Notes:

Driller: Logger:

N33.585786°, W96.163415°

N - SPT Data (Blows/Ft)

P - Pocket Penetrometer (tsf)

T - Torvane (tsf)

L - Lab Vane Shear (tsf)

D R

Y D

E N

S

IT

Y pc f)

D R

Y D

E N

S

IT

Y pc f)

Z E

R O

S W

E

LL

P R

E S

S U

R E ps f)

W.E.S.T. Drilling, Inc. W.E.S.T. Drilling, Inc.

Sam Rayburn Memorial Veterans Center - Parking Upgrades Bonham, Texas

G4393-15

Geoprobe

Direct Push

1.5" HMAC

5" Concrete

3" Flex Base

FAT CLAY(CH) stiff; dark gray with light gray; moist; with trace roots

FAT CLAY(CH) stiff; gray with light brown; moist; mottled

Bottom of Boring @ 5'

0 058 16 42 97

P=3.0

P=3.2

P=2.6

P=2.7

LOG OF BORING B-2

PL F

R

E E

S W

E

LL

PI

7/28/15

SWELL

TEST

Perched:Est.:

Dry and open upon completion.

Qu (tsf)

P

LA

S T

IC

IT

Y

IN

D E

X

M

IN

U S

S

IE

V

E

P

LU

S

S

IE

V

E

P

LU

S

S

IE

V

E

PPR (tsf) Moisture Content

Plastic Limit

Natural Moisture Content and

Atterberg Limits

Liquid Limit

1.0 2.0 3.0 4.0

1.0 2.0 3.0 4.0

BLOW COUNT COMPRESSIVE

STRENGTH

Torvane (tsf)

20 40 60 80

D E

P T

H ft)

Water Level

S A

M P

LE

S USC

Measured:

W A

T E

R L

E V

E L

G E

O

LO

G

IC

U N

IT

Water Observations:

MAIN OFFICE

1717 East Erwin

Tyler, Texas 75702

(903) 595-4421

ETTL

ENGINEERS &

CONSULTANTS

M O

IS

T

U R

E C

O N

T E

N T

DRILL RIG:

BORING TYPE:

F

IE

LD

S T

R E

N G

T H

D A

T A

DATE

SURFACE ELEVATION

ATTERBERG

LIMITS(%)

SIEVE

ANALYSIS

1 2 3 4

M O

IS

T

U R

E C

O N

T E

N T

20 40 60 80

C O

M P

R E

S S

IV

E

S T

R E

N G

T H ts f)

M O

IS

T

U R

E C

O N

T E

N T

LI

Q

U

ID

L

IM

IT

P

LA

S T

IC

L

IM

IT

MATERIAL DESCRIPTION

PROJECT:

PROJECT NO.:

LL

GPS Coordinates:

Key to Abbrevations: Notes:

Driller: Logger:

N33.585513°, W96.163421°

N - SPT Data (Blows/Ft)

P - Pocket Penetrometer (tsf)

T - Torvane (tsf)

L - Lab Vane Shear (tsf)

D R

Y D

E N

S

IT

Y pc f)

D R

Y D

E N

S

IT

Y pc f)

Z E

R O

S W

E

LL

P R

E S

S U

R E ps f)

W.E.S.T. Drilling, Inc. W.E.S.T. Drilling, Inc.

Sam Rayburn Memorial Veterans Center - Parking Upgrades Bonham, Texas

G4393-15

Geoprobe

Direct Push

2" HMAC

4" Concrete

4" Flex Base

FAT CLAY(CH) stiff; dark gray with light gray; moist

Bottom of Boring @ 5'

1 053 16 37 96P=2.6

LOG OF BORING B-3

PL F

R

E E

S W

E

LL

PI

7/28/15

SWELL

TEST

Perched:Est.:

Dry and open upon completion.

Qu (tsf)

P

LA

S T

IC

IT

Y

IN

D E

X

M

IN

U S

S

IE

V

E

P

LU

S

S

IE

V

E

P

LU

S

S

IE

V

E

PPR (tsf) Moisture Content

Plastic Limit

Natural Moisture Content and

Atterberg Limits

Liquid Limit

1.0 2.0 3.0 4.0

1.0 2.0 3.0 4.0

BLOW COUNT COMPRESSIVE

STRENGTH

Torvane (tsf)

20 40 60 80

D E

P T

H ft)

Water Level

S A

M P

LE

S USC

Measured:

W A

T E

R L

E V

E L

G E

O

LO

G

IC

U N

IT

Water Observations:

MAIN OFFICE

1717 East Erwin

Tyler, Texas 75702

(903) 595-4421

ETTL

ENGINEERS &

CONSULTANTS

M O

IS

T

U R

E C

O N

T E

N T

DRILL RIG:

BORING TYPE:

F

IE

LD

S T

R E

N G

T H

D A

T A

DATE

SURFACE ELEVATION

ATTERBERG

LIMITS(%)

SIEVE

ANALYSIS

1 2 3 4

M O

IS

T

U R

E C

O N

T E

N T

20 40 60 80

C O

M P

R E

S S

IV

E

S T

R E

N G

T H ts f)

M O

IS

T

U R

E C

O N

T E

N T

LI

Q

U

ID

L

IM

IT

P

LA

S T

IC

L

IM

IT

MATERIAL DESCRIPTION

PROJECT:

PROJECT NO.:

LL

GPS Coordinates:

Key to Abbrevations: Notes:

Driller: Logger:

N33.585366°, W96.163200°

N - SPT Data (Blows/Ft)

P - Pocket Penetrometer (tsf)

T - Torvane (tsf)

L - Lab Vane Shear (tsf)

D R

Y D

E N

S

IT

Y pc f)

D R

Y D

E N

S

IT

Y pc f)

Z E

R O

S W

E

LL

P R

E S

S U

R E ps f)

W.E.S.T. Drilling, Inc. W.E.S.T. Drilling, Inc.

Sam Rayburn Memorial Veterans Center - Parking Upgrades Bonham, Texas

G4393-15

Geoprobe

Direct Push

1" HMAC

6" Concrete

4" Flex Base

FAT CLAY(CH) stiff; light gray with dark gray; moist; mottled; calcareous

--very stiff

--stiff

Bottom of Boring @ 5'

12 460 16 44 8619P=3.0

P=2.4

P=3.4

P=2.2

LOG OF BORING B-4

PL F

R

E E

S W

E

LL

PI

7/28/15

SWELL

TEST

Perched:Est.:

Dry and open upon completion.

Qu (tsf)

P

LA

S T

IC

IT

Y

IN

D E

X

M

IN

U S

S

IE

V

E

P

LU

S

S

IE

V

E

P

LU

S

S

IE

V

E

PPR (tsf) Moisture Content

Plastic Limit

Natural Moisture Content and

Atterberg Limits

Liquid Limit

1.0 2.0 3.0 4.0

1.0 2.0 3.0 4.0

BLOW COUNT COMPRESSIVE

STRENGTH

Torvane (tsf)

20 40 60 80

D E

P T

H ft)

Water Level

S A

M P

LE

S USC

Measured:

W A

T E

R L

E V

E L

G E

O

LO

G

IC

U N

IT

Water Observations:

MAIN OFFICE

1717 East Erwin

Tyler, Texas 75702

(903) 595-4421

ETTL

ENGINEERS &

CONSULTANTS

M O

IS

T

U R

E C

O N

T E

N T

DRILL RIG:

BORING TYPE:

F

IE

LD

S T

R E

N G

T H

D A

T A

DATE

SURFACE ELEVATION

ATTERBERG

LIMITS(%)

SIEVE

ANALYSIS

1 2 3 4

M O

IS

T

U R

E C

O N

T E

N T

20 40 60 80

C O

M P

R E

S S

IV

E

S T

R E

N G

T H ts f)

M O

IS

T

U R

E C

O N

T E

N T

LI

Q

U

ID

L

IM

IT

P

LA

S T

IC

L

IM

IT

MATERIAL DESCRIPTION

PROJECT:

PROJECT NO.:

LL

GPS Coordinates:

Key to Abbrevations: Notes:

Driller: Logger:

N33.585221°, W96.163377°

N - SPT Data (Blows/Ft)

P - Pocket Penetrometer (tsf)

T - Torvane (tsf)

L - Lab Vane Shear (tsf)

D R

Y D

E N

S

IT

Y pc f)

D R

Y D

E N

S

IT

Y pc f)

Z E

R O

S W

E

LL

P R

E S

S U

R E ps f)

W.E.S.T. Drilling, Inc. W.E.S.T. Drilling, Inc.

Sam Rayburn Memorial Veterans Center - Parking Upgrades Bonham, Texas

G4393-15

Geoprobe

Direct Push

APENNDIX B

Laboratory Testing

Upon return to the laboratory, a geotechnical engineer visually examined all samples and several specimens were selected for representative identification of the substrata. By determining the

Atterberg liquid and plastic limits (ASTM D 4318) and percentage of fines passing the No. 200 sieve

(ASTM D 1140), field classification of the various strata was verified. Also conducted were natural moisture content tests (ASTM D 2216). These results are presented in the individual log of boring provided in Appendix A.

APPENDIX C

SpectraPave4 Pro Report

SpectraPave4 PRO™ Pavement Optimization Design Analysis

Design Parameters for AASHTO (1993) Equation

Reliability (%)

Standard Normal Deviate

Standard Deviation

= 85

= -1.036

= 0.49

Initial Serviceability

Terminal Serviceability

Change in Serviceability

= 4.2

= 2.0

= 2.2

Aggregate fill shall conform to following requirement:

D50 <= 27mm (Base course)

Unstabilized Section Material Properties

Layer Description Cost

($/ton) Layer coefficient Drainage factor

ACC1

Asphalt Wearing

Course 70 0.420 N/A

ABC

Aggregate Base

Course 20 0.140 .94

SBC Subbase Course 16 0.080 .94

Stabilized Section Material Properties

Layer Description Cost

($/ton) Layer coefficient Drainage factor

ACC1

Asphalt Wearing

Course 70 0.420 N/A

MSL

Mechanically

Stabilized Base Cour 20 0.644 .94

None Subbase Course 16 0.080 .94

Unstabilized Pavement

ACC1 2.00 (in)

ABC 6.00 (in)

SBC 8.00 (in)

Subgrade Modulus = 4,500 (psi) Structural Number = 2.231 Calculated Traffic (ESALs) = 27,000

Stabilized Pavement

ACC1 2.00 (in)

MSL 6.00 (in)

Tensar TX7 (Overlap=1.7ft)

Subgrade Modulus = 4,500 (psi) Structural Number = 4.472 Calculated Traffic (ESALs) = 2,808,000

LIMITATIONS OF THE REPORT

The designs, illustrations, information and other content included in this report are necessarily general and conceptual in nature, and do not constitute engineering advice or any design intended for actual construction. Specific design recommendations can be provided as the project develops.

Project Name SRM Veterans Center - Parking Upgrades

Company Name ETTL Engineers & COnsultants, Inc.

Designer Owen Sanderson Date 8/14/2015

This document was prepared using SpectraPave4 PRO™ Software Version 4.6.1 Developed by Tensar International Corporation

Copyright 1998 - 2014, All Rights Reserved.

P ri nt ed o n

-1

4-

C

T en sa r In te rn at io na l

C o rp o ra ti o n\

S pe ct ra

P av e4 P

R O

\P av em en t D es ig n.

sp

4p T hi n

A sp ha lt

P av em en t

T W

H E di ti o n

Design Parameters for AASHTO (1993) Equation

Reliability (%)

Standard Normal Deviate

Standard Deviation

= 85

= -1.036

= 0.49

Initial Serviceability

Terminal Serviceability

Change in Serviceability

= 4.2

= 2.0

= 2.2

Aggregate fill shall conform to following requirement:

D50 <= 27mm (Base course)

Unstabilized Section Material Properties

Layer Description Cost

($/ton) Layer coefficient Drainage factor

ACC1

Asphalt Wearing

Course 70 0.420 N/A

ABC

Aggregate Base

Course 20 0.140 .94

SBC Subbase Course 16 0.080 .94

Stabilized Section Material Properties

Layer Description Cost

($/ton) Layer coefficient Drainage factor

ACC1

Asphalt Wearing

Course 70 0.420 N/A

MSL

Mechanically

Stabilized Base Cour 20 0.582 .94

None Subbase Course 16 0.080 .94

Unstabilized Pavement

ACC1 3.00 (in)

ABC 8.00 (in)

SBC 8.00 (in)

Subgrade Modulus = 4,500 (psi) Structural Number = 2.914 Calculated Traffic (ESALs) = 150,000

Stabilized Pavement

ACC1 3.00 (in)

MSL 8.00 (in)

Tensar TX7 (Overlap=1.7ft)

Subgrade Modulus = 4,500 (psi) Structural Number = 5.637 Calculated Traffic (ESALs) = 15,754,000

LIMITATIONS OF THE REPORT

The designs, illustrations, information and other content included in this report are necessarily general and conceptual in nature, and do not constitute engineering advice or any design intended for actual construction. Specific design recommendations can be provided as the project develops.

Project Name SRM Veterans Center - Parking Upgrades

Company Name ETTL Engineers & COnsultants, Inc.

Designer Owen Sanderson Date 8/14/2015

This document was prepared using SpectraPave4 PRO™ Software Version 4.6.1 Developed by Tensar International Corporation

Copyright 1998 - 2014, All Rights Reserved.

P ri nt ed o n

-1

4-

C

T en sa r In te rn at io na l

C o rp o ra ti o n\

S pe ct ra

P av e4 P

R O

\P av em en t D es ig n.

sp

4p S ta nd ar d

A sp ha lt

P av em en t

T W

H E di ti o n

Design Parameters for AASHTO (1993) Equation

Reliability (%)

Standard Normal Deviate

Standard Deviation

= 85

= -1.036

= 0.49

Initial Serviceability

Terminal Serviceability

Change in Serviceability

= 4.2

= 2.0

= 2.2

Aggregate fill shall conform to following requirement:

D50 <= 27mm (Base course)

Unstabilized Section Material Properties

Layer Description Cost

($/ton) Layer coefficient Drainage factor

ACC1

Asphalt Wearing

Course 70 0.420 N/A

ACC2

Dense-graded Asphalt Course

70 0.400 N/A

ABC

Aggregate Base

Course 20 0.140 .94

SBC Subbase Course 16 0.080 .94

Stabilized Section Material Properties

Layer Description Cost

($/ton) Layer coefficient Drainage factor

ACC1

Asphalt Wearing

Course 70 0.420 N/A

ACC2

Dense-graded Asphalt Course

70 0.400 N/A

MSL

Mechanically

Stabilized Base Cour 20 0.608 .94

None Subbase Course 16 0.080 .94

Unstabilized Pavement

ACC1 2.00 (in)

ACC2 2.50 (in)

ABC 7.00 (in)

SBC 8.00 (in)

Subgrade Modulus = 4,500 (psi) Structural Number = 3.363 Calculated Traffic (ESALs) = 389,000

Stabilized Pavement

ACC1 2.00 (in)

ACC2 2.50 (in)

MSL 7.00 (in)

Tensar TX7 (Overlap=1.7ft)

Subgrade Modulus = 4,500 (psi) Structural Number = 5.841 Calculated Traffic (ESALs) = 20,738,000

LIMITATIONS OF THE REPORT

The designs, illustrations, information and other content included in this report are necessarily general and conceptual in nature, and do not constitute engineering advice or any design intended for actual construction. Specific design recommendations can be provided as the project develops.

Project Name SRM Veterans Center - Parking Upgrades

Company Name ETTL Engineers & COnsultants, Inc.

Designer Owen Sanderson Date 8/14/2015

This document was prepared using SpectraPave4 PRO™ Software Version 4.6.1 Developed by Tensar International Corporation

Copyright 1998 - 2014, All Rights Reserved.

P ri nt ed o n

-1

4-

C

T en sa r In te rn at io na l

C o rp o ra ti o n\

S pe ct ra

P av e4 P

R O

\P av em en t D es ig n.

sp

4p S ta nd ar d

A sp ha lt

P av em en t

T W

H E di ti o n