A04_1_9_5_Geotechnial_Engineering_Report(3).pdf

REPORT

GEOTECHNICAL INVESTIGATION

PROPOSED HEADQUARTER AND SHOP BUILDINGS

1206 APC NWR ROAD

EAGLE LAKE, TEXAS 77434

All-Terra Project No.: AE21-1056

PREPARED FOR:

US Fish and Wildlife Service P.O. Box 1306

Albuquerque, NM 87103-1306

PREPARED BY:

All-Terra Engineering, Inc.

6200 Rothway, Suite 140 Houston, Texas 77041

(713) 574-2371 (office)

(713) 574-2372 (fax)

April 12, 2021

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6200 Rothway, Suite 140, Houston, TX 77041 Tel: 713-574-2371 Fax: 713-574-2372

TBPE Firm No. 9770 All-Terra Engineering, Inc.

Geotechnical Engineering * Construction Materials Testing

April 12, 2021

US Fish and Wildlife Service P. O. Box 1306 Albuquerque, NM 87103-1306

Attn: Mr. Robert C. Rayner

Re: Report Geotechnical Investigation

Proposed Headquarter and Shop Buildings 1206 APC NWR Road Eagle Lake, Texas 77434

Project No.: AE21-1056

Dear Mr. Rayner:

All-Terra Engineering, Inc. is pleased to transmit our report of the geotechnical investigation for the above-referenced project. The report provides data, analyses results, and recommendations that may be used for the design and construction of the proposed buildings and associated pavements.

We appreciate the opportunity to perform this geotechnical investigation and look forward to continued participation during the design and construction phases of this project. If you have any questions pertaining to this report or if we may be of further service, please contact me at your convenience.

Respectfully submitted, All-Terra Engineering, Inc.

Bonifacio F. Musngi, Jr., P.E.

Senior Geotechnical Engineer

File: c://2021/AE21-1056_report.docx

04-12-2021

Project No. AE21-1056 April 12, 2021

TABLE OF CONTENTS

Page No.

1.0 Introduction and Summary

1.1 Introduction

1.2 Summary of Findings

1.2.1 Subsurface Soil Strata

1.2.2 Groundwater Condition

1.2.3 Potential for Vertical Rise

1.3 Summary of Recommendations

1.3.1 Recommended Site and Subgrade Preparation – Proposed

Buildings

1.3.2 Foundation Recommendations

1.3.3 Recommended Site and Subgrade Preparation/Stabilization – Proposed Pavements

1.3.4 Design Recommendations for Proposed Pavements

2.0 Field Investigation

3.0 Laboratory Testing

4.0 Foundation Maintenance

5.0 Construction Considerations

6.0 Closing Remarks

APPENDIX

Plate No. 1 Vicinity Map Plate No. 2 Locations of Borings Plate Nos. 3 - 6 Boring Logs (Boring Nos. B-1 through B-4) Plate No. 7 Key to Symbols Used in Boring Logs

April 12, 2021 Page: 1

REPORT

GEOTECHNICAL INVESTIGATION

PROPOSED HEADQUARTER AND SHOP BUILDINGS

1206 APC NWR ROAD

EAGLE LAKE, TEXAS 77434

1.0 INTRODUCTION AND SUMMARY

1.1 Introduction

This report presents the results of the geotechnical investigation that may be used to support the design and construction of the proposed headquarter and shop buildings as well as the associated pavements that are being planned/designed for construction at 1206 APC NWR Road in Eagle Lake, Texas. The areas for the proposed development project are relatively flat with an existing concrete slab within the proposed shop building and vegetation consisting of scattered trees and well-trimmed grasses within the proposed office building. The site location for the proposed development is shown on Plate No. 1.

It is our understanding that the proposed project consists of a single story office building (footprint area of about 6,400 square feet, loadings to be typical of a commercial construction), a pre-engineered steel shop buildings (footprint area of about 4,000 square feet, loadings typical of pre-engineered moment frame building), and associated pavements (concrete or asphalt) for access drives and parking spaces. The objectives of this geotechnical investigation were to define the subsurface soils and groundwater conditions within the project area and provide data, parameters, and recommendations that may be used for the proposed buildings and associated pavements.

This geotechnical investigation was performed by All-Terra Engineering, Inc. for US Fish and Wildlife Service in accordance with All-Terra Proposal No. APE21-784 dated February 18, 2021 and signed authorization by Mr. Robert C. Rayner on February 24, 2021.

The scope of work for this geotechnical investigation consisted of the following activities:

Drill and sample a total of four (4) geotechnical borings to a depth of 20 feet beneath the surface within the project areas as shown on the attached Plate No. 2.

Obtain disturbed soil samples from the borings with continuous samples being taken from the ground surface to a depth of 12 feet and at 5-foot intervals thereafter.

Measure the depth to groundwater during drilling and approximately 15 minutes after the completion of drilling.

Backfill the bore holes with soil cuttings after the completion of the drilling activities.

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Perform laboratory soil tests on samples obtained during the drilling of the borings in order to determine the physical and engineering properties of the soil. Laboratory testing included Atterberg limits tests, moisture content tests, and percent soil finer than the No. 200 sieve tests.

Prepare boring logs based upon visual soil classifications and the results of laboratory tests.

Characterize the site subsoil and groundwater conditions.

Perform potential vertical rise of the site soils within the project areas as well as bearing capacity and settlement analyses for foundations which may be used to support the loads of the proposed buildings.

Provide uplift and lateral load parameters for the recommended foundations.

Provide recommendations pertaining to subgrade preparation as well as foundation, floor slab design, and construction for the proposed buildings.

Provide pavement section recommendations as well as subgrade preparation/stabilization recommendations for the proposed access drives and parking areas.

Prepare and submit an electronic file of the report that presents the data, findings, and recommendations of the geotechnical investigation.

1.2 Summary of Findings

The pertinent findings of this geotechnical investigation pertaining to the design and construction of the proposed buildings are provided below.

1.2.1 Subsurface Soil Strata

The subsurface soil strata at the boring locations within the proposed development are described by the laboratory test results and the boring logs for Boring Nos. B-1 through B-4 as shown on Plate Nos. 3 through 6.

Data from the 4 geotechnical borings drilled suggest that the upper 20 feet of the overburden soils are composed of one (1) soil layer as described below.

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Layer Depth *

(ft) Soil Description

I 0 - 20 Tan, brown, and dark brown SILTY SAND (SM) and POORLY GRADED SAND WITH SILT (SP-SM), loose to medium dense.

* Measured below the ground surface at the time of our field exploration activities.

Laboratory testing was performed on selected samples of the subsurface materials obtained to classify the soils in accordance with ASTM D 2487 and to define the engineering properties of the soils. Portions of the test results indicating the high and low values of specific testing are provided in the table below:

LAYER DEPTH

(FT)

LIQUID

LIMIT

PLASTICITY

INDEX

MOISTURE

CONTENT

PASSING NO.

200 SIEVE

HIGH LOW HIGH LOW HIGH LOW HIGH LOW

I 0 - 20 Non-Plastic 23.0 4.0 28.4 6.8

1.2.2 Groundwater Condition

Groundwater was encountered at depths ranging from 8.0 to 9.0 feet beneath the surface during the drilling of the borings and the borings caved at depths ranging from 8.0 to 8.5 feet beneath the surface approximately 15 minutes after the completion of drilling. The bore holes were immediately backfilled with soil cuttings after the completion of the drilling activities.

1.2.3 Potential for Vertical Rise

The results of laboratory plasticity tests indicated that the site soils within the development area consisted of sandy soils that exhibited no plasticity and shrink/swell potential. Potential Vertical Rise (PVR) was evaluated using the Texas Department of Transportation (TxDOT) Method (TEX-124-E).

1.3 Summary of Recommendations

The recommendations, as summarized below, are provided for use in the design and construction of the proposed buildings and associated pavements.

1.3.1 Recommended Site and Subgrade Preparation – Proposed Buildings To provide adequate foundation support to the proposed buildings, where a slab-on-grade floor is being considered, it is vital that the proposed building areas be properly prepared. The contractor should establish and maintain positive site drainage throughout the construction period because surface

April 12, 2021 Page: 4 soils are sensitive to moisture. Wet soil conditions during and following rainy weather will adversely affect construction activities. If the surface soils become overly saturated and unable to support construction activity, or rut and pump under equipment traffic, construction should not proceed until the surface conditions have improved or have been remediated. Remediation typically involves disking, drying, and recompaction during dry weather;

excavation and replacement; or treatment with a chemical additive.

Chemical treatment (stabilization) of the building pad subgrade before fill placement is effective in creating a firm/stable subgrade on which construction may proceed if construction commences during or after a wet period. It is then recommended that site and subgrade preparation include the following activities.

Establish positive site drainage and install storm water drainage structures, as needed.

Remove existing concrete slab, as applicable, and strip vegetation, organic topsoil to a depth of at least 6 inches and as necessary to achieve the desired grade.

Proofroll the exposed subgrade soils with a 15-ton roller or equivalent suitable equipment as approved by the engineer, observing the soils during proofrolling so as to detect any wet, soft, loose, or unstable/pumping soils and treating such soils with suitable drying or stabilizing agents or removing the unsuitable soils and replacing with properly compacted select fill. Proofrolling should extend at least 5 feet beyond the building limits. The geotechnical engineer or an experienced soil technician should observe proofrolling operations to delineate areas that require remediation, if any. The proofrolling activities should be properly documented to ensure that the building areas had been properly prepared prior to the placement of the building pad fill soils.

Compact the exposed subgrade soils to an in-place dry density equal to at least 95% of the maximum standard dry density (ASTM D 698) at a moisture content within 2% of the optimum moisture content.

Place at least 2.0 feet of properly compacted select fill and as necessary to achieve the desired grade elevation. Fill placement should extend at least 5 feet beyond the building limits.

Select fill should consist of inactive lean clays (classified as CL soils) or clayey sands (classified as SC soils) with a maximum liquid limit of 35 and a plasticity index range of 8 to 20. The select fill should be placed in 8-inch thick loose lifts (6-inch compacted lifts) and compacted to an in-place dry density equal to at least 95% of the maximum standard dry density (ASTM D

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698) at a moisture content within 2% of the optimum moisture content.

Testing of each 6-inch thick lift of select fill should be at a frequency of one in-place density and moisture content test for each 2,000 square feet or less with a minimum of three tests per lift. The site sandy soil exhibited no plasticity and not suitable as select fill material for the building pad.

Depending upon weather conditions, difficulty may be encountered in adequately densifying/compacting the surficial site soils. If the surficial soils are unsuitably wet, excess pore pressures (“pumping”) may develop and excessive displacement of the subgrade soils may occur during site and subgrade preparation. If the site subgrade soils become unsuitably wet, the construction contractor should:

bring the subgrade soils to within 2% of the optimum moisture content by discing/raking these materials, or dry the soils by blending a stabilizing agent (lime or fly ash) with the unsuitably wet soils, or remove the unsuitably wet soils and replace with properly compacted select fill having an acceptable moisture content.

Additional Considerations for Slab-on-Grade Floors:

Vapor retarder not less than 10 mils thick should be placed under the concrete floor slab-on-grade to reduce the transmission of water vapor from the foundation soil through the concrete slab. For slabs exposed to ambient conditions of temperature and humidity, a vapor retarder also reduces the amount of water that will condense on the slab during periods of high relative humidity. Local practice is to place the concrete floor directly on the vapor retarder. The vapor retarder should function as a slip-sheet to reduce subgrade drag friction. The vapor retarder should be installed according to the guidelines of ASTM E 1643.

1.3.2 Foundation Recommendations

The loads of the proposed buildings may be supported on foundations systems as provided below.

Shallow Spread Footings Provided the site and subgrade preparation recommendations provided in Section 1.3.1 of this report are followed and at least 2.0 feet of properly compacted select fill is placed over the foundation area and to a distance of at least five (5) feet beyond the perimeters of the foundation, it is our opinion that the planned building construction can be supported by shallow spread footings. The shallow spread footings should have a maximum width of about 6 feet, be founded at a depth of at least 3 feet below the desired

April 12, 2021 Page: 6 finished grade, and be designed for maximum allowable net bearing pressures of 2,400 psf for axial compression dead loads plus sustained live loads and 3,600 psf for axial compression dead loads plus sustained and transient live loads.

Uplift Capacity of Footings. The uplift capacity of footings will generally consist of the dead load of the footings plus the weight of the backfill (130 pcf for select fill soil backfill) above them. Use a factor of safety of 2.0 to obtain the allowable uplift capacity of the footings.

Lateral Resistance of Footings. The lateral resistance of footings consists of sliding resistance between the base of the foundation and the foundation soils plus the passive resistance of the foundation soils against the footings.

At a depth of at least 3 feet for the footings where the footing is seated on the sandy soil, the coefficient of friction that may be used is 0.45 to obtain frictional resistance underneath the base of the footing. The passive resistance is due to the weight of equivalent fluid of the site soil of about 250 psf per foot of depth. To aid in resisting lateral loads, a keywall or turn down at the base of the spread footing may be provided to make use of the passive resistance of the soil against the face of the keywall or turn down.

The weight of the footing and the weight of the soil backfill (130 pcf for select fill soil backfill) above the footing should also be used to counter the effect of overturning of the footing foundation. For design purposes, the footings should be designed for factors of safety values of 1.5 and 2.0 against sliding and overturning failure, respectively.

If a cluster of closely spaced footings (i.e., if the center to center spacing of the footings is less than two times the width of the footing) are planned, All-Terra Engineering, Inc. should be contacted to calculate the amount of settlement.

Footing foundations should be prepared by excavating the overburden soils to the final foundation grade elevation, compacting the foundation subgrade soils to an in-place dry density equal to at least 95% of the maximum dry density at a moisture content within 2% of the optimum moisture content as determined by ASTM D 698. A tamping plate hand compactor or other suitable impact compactor may be used to perform the compaction. Without proper compaction of the spread footing foundation soils, settlement of the shallow spread footings could exceed 1 inch. The foundation excavations should be observed by a representative of All-Terra Engineering, Inc. or a qualified personnel prior to steel or concrete placement to assess that the foundation materials are capable of supporting the design loads and are consistent with the materials discussed in this report. Soft, loose, or unstable soil zones encountered at the bottom of the footing excavations should be removed and replaced with properly compacted select fill as directed by the geotechnical engineer. To prevent cave-ins of the walls of the foundation excavations, temporary forms may be necessary.

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After opening, footing excavations should be observed and concrete placed as quickly as possible to avoid exposure of the footing bottoms to wetting and drying. Surface run-off water should be drained away from the excavations and not be allowed to pond. The foundation concrete should be placed during the same day the excavation is made. If it is required that footing excavations be left open for more than one day, they should be protected to minimize evaporation or entry of moisture.

Grade beams should be at least 12 inches wide, extend at least 1.5 feet below finished grade, and be founded on the spread footings. Carton forms to create a void beneath the grade beams and the subgrade soils are not required. Grade beams may be formed directly on the properly prepared building pad soils.

The floor for the proposed buildings may consist of a slab-on-grade floor with site preparation performed as described in Section 1.3.1 of this report. An allowable net bearing pressure of 600 psf can be used for slab-on-grade bearing on properly compacted select fill.

Continuous Footings/Grade Beams Provided the site and subgrade preparation recommendations provided in Section 1.3.1 of this report are followed and at least 2.0 feet of properly compacted select fill is placed over the foundation area and to a distance of at least five (5) feet beyond the perimeters of the foundation, it is our opinion that the planned building construction can also be supported on a conventional continuous footing and/or grade beam foundation system. Foundations should be placed at least two (2) feet below finished grade and be designed for net allowable bearing pressures of 2,000 psf for dead load plus sustained live loads and 3,000 psf for dead loads plus sustained and transient live loads, whichever results in a larger bearing area. These values consider a safety factor of at least 3 and 2, respectively, against a bearing capacity failure.

Uplift Capacity of Footings. The uplift capacity of footings will generally consist of the dead load of the footings plus the weight of the backfill (130 pcf for select fill soil backfill) above them. Use a factor of safety of 2.0 to obtain the allowable uplift capacity of the footings.

Lateral Resistance of Footings. The lateral resistance of footings consists of sliding resistance between the base of the foundation and the foundation soils plus the passive resistance of the foundation soils against the footings.

At a depth of at least 2 feet for the footings where the footing is seated on the sandy soil, the coefficient of friction that may be used is 0.45 to obtain frictional resistance underneath the base of the footing. The passive resistance is due to the weight of equivalent fluid of the site soil of about 250 psf per foot of depth. To aid in resisting lateral loads, a keywall or turn down at the base of the footing may be provided to make use of the passive

April 12, 2021 Page: 8 resistance of the soil against the face of the keywall or turn down. The weight of the footing and the weight of the soil backfill (130 pcf for select fill soil backfill) above the footing should also be used to counter the effect of overturning of the footing foundation. For design purposes, the footings should be designed for factors of safety values of 1.5 and 2.0 against sliding and overturning failure, respectively.

Footing foundations should be prepared by excavating the overburden soils to the final foundation grade elevation, compacting the foundation subgrade soils to an in-place dry density equal to at least 95% of the maximum dry density at a moisture content within 2% of the optimum moisture content as determined by ASTM D 698. A tamping plate hand compactor or other suitable impact compactor may be used to perform the compaction. Without proper compaction of the continuous footing/grade beam foundation soils, settlement of the continuous footings/grade beam footings could exceed 1 inch.

The foundation excavations should be observed by a representative of All- Terra Engineering, Inc. or qualified personnel prior to steel or concrete placement to assess that the foundation materials are capable of supporting the design loads and are consistent with the materials discussed in this report.

Soft, loose, or unstable soil zones encountered at the bottom of the footing excavations should be removed and replaced with properly compacted structural fill as directed by the geotechnical engineer.

After opening, footing excavations should be observed and concrete placed as quickly as possible to avoid exposure of the footing bottoms to wetting and drying. Surface run-off water should be drained away from the excavations and not be allowed to pond. The foundation concrete should be placed during the same day the excavation is made. If it is required that footing excavations be left open for more than one day, they should be protected to minimize evaporation or entry of moisture. To prevent cave-ins of the walls of the foundation excavations, temporary forms may be necessary.

The floor for the proposed buildings may consist of a slab-on-grade floor with site preparation performed as described in Section 1.3.1 of this report. An allowable net bearing pressure of 600 psf can be used for slab-on-grade bearing on properly compacted select fill.

1.3.3 Recommended Site and Subgrade Preparation/Stabilization – Proposed Pavements Initial site preparation within the pavement areas requires removal of any vegetation, wet, soft, loose, unstable/pumping soils at the ground surface.

The depth of removal of the natural soils, typically to a depth of about 6 inches, may vary across the development area and could be as much as 2 feet

April 12, 2021 Page: 9 especially in areas where wet, soft, loose, or pumping/unstable soils are encountered. The exposed soils should be proof-rolled using a 15-ton roller or equivalent equipment to detect any soft, unstable areas under the supervision of the soil consultants or a qualified personnel. The exposed soils should be proof-rolled and compacted to at least 95% of the maximum dry density at a moisture content within 2% of the optimum moisture content as determined by ASTM D-698.

To provide a stable foundation for the proposed new pavements, any wet, soft, loose, unstable/pumping soils encountered should be processed by:

drying the soils to within 2% of the optimum moisture content by raking/discing/aerating these materials, drying the soils by blending a stabilizing agent such as lime or fly ash with the unsuitably wet soils, or removing the unsuitably wet soils and replacing with properly compacted suitable earth fill or select fill having an acceptable moisture content.

Suitable earth fill may consist of on-site soils that are clean and free of organics and deleterious substances. Select fill should consist of inactive lean clays (classified as CL soils) or clayey sands (classified as SC soils) with a maximum liquid limit of 35 and a plasticity index range of 8 to 20. The suitable earth fill or select fill should be placed in 8-inch thick loose lifts (6-inch compacted lifts) and compacted to an in-place dry density equal to at least 95% of the maximum standard dry density (ASTM D 698) at a moisture content within 2% of the optimum moisture content.

Based on the results of our field and laboratory tests, the surficial soils generally consisted of sandy soils. Therefore, to improve strength, maintain compaction, and provide improved performance of the pavements, the subgrade soils will require stabilization. The exposed subgrade soils, could be easily handled, retain compaction, and minimize or eliminate rutting if stabilized by the addition of 3% lime and 8% fly ash, expressed as percent of the dry weight of the exposed soils. Using a unit dry weight of 110 pounds per cubic foot for the site surfical soils, the amounts of stabilization should be about 15 pounds of lime per square yard for a depth of 6 inches and 40 pounds of fly ash per square yard for a depth of 6 inches (for a subgrade thickness of 8 inches, use 20 pounds of lime per square yard and 53 pounds of fly ash per square yard). The blended soil-lime-fly ash mixture should be compacted to an in-place dry density equal to at least 95% of the maximum standard dry density (ASTM D 698).

Stabilization procedures may be performed in accordance with Item 265 titled “Fly Ash or Lime-Fly Ash Treatment (Road-Mixed)” of the 2014 Texas

April 12, 2021 Page: 10

Department of Transportation Specifications, or the applicable guidelines and requirements of the governing agency (city of Eagle Lake or Colorado County) within the project area.

Lime-fly ash stabilization should extend a minimum of 1 foot beyond the edges of the pavement in order to preclude edge failure of the pavement. It is recommended that the percentages of lime and fly ash for use in stabilization be determined on the exposed pavement subgrade soils during construction.

In lieu of the use of lime and fly ash for stabilization, cement may also be used to stabilize the site sandy soils. Subgrade stabilization may be performed using 7% cement, expressed as percent of the dry weight of the exposed soils. Using a unit dry weight of 110 pounds per cubic foot for the site soils, the amounts of stabilization should be about 35 pounds of lime per square yard for a depth of 6 inches (for a subgrade thickness of 8 inches, use 46 pounds of cement per square yard). The blended soil-cement mixture should be compacted to an in-place dry density equal to at least 95% of the maximum standard dry density (ASTM D 558). Stabilization procedures may be performed in accordance with Item 275 titled “Cement Treatment (Road- Mixed)” of the 2014 Texas Department of Transportation Specifications or the applicable requirements and guidelines of the governing agency (city of Eagle Lake or Colorado County) within the project area.

For pavement areas that are relatively small and stabilization of the existing subgrade is not cost effective, cement stabilized sand may be used. It will require that the existing subgrade be excavated to the grade that will allow the layer of cement stabilized sand to be placed.

1.3.4 Design Recommendations for Proposed Pavements

The proposed pavements that are associated with the proposed development project should consist of the following:

RIGID PAVEMENTS:

Material Traffic A (inches)

Traffic B (inches)

Traffic C (inches)

Reinforced Concrete Pavement 6.0* 7.0 8.0

Stabilized Subgrade 6.0 6.0 8.0

* For parking spaces, concrete thickness may be reduced to 5 inches.

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FLEXIBLE PAVEMENTS:

Material Traffic A (inches)

Traffic B (inches)

Traffic C (inches)

Asphalt Surface Type D 1.5 2.0 3.0

Crushed Aggregate Course* 8.0 8.0 10.0

Stabilized Subgrade 6.0 8.0 8.0

* crushed concrete base material may be used as an option

Traffic classifications A, B, and C are as follows:

Traffic A - passenger cars and light to medium duty traffic.

Traffic B - trash pickup areas and other areas where heavy haul and heavy duty trucks are allowed to operate.

Traffic B - frequent/normal heavy duty traffic use such as heavy haul trucks, 18-wheelers, and other heavy loaded multi-axle trucks.

Pavement subgrade soil preparation should comply with the recommendations provided in Section 1.3.3 of this report.

All related civil design factors such as drainage, cross-sectional configurations, surface elevations, and environmental factors that will significantly affect the service life of the pavement should be included in the preparation of the construction drawings and specifications.

2.0 FIELD INVESTIGATION

For this geotechnical investigation, four (4) geotechnical borings (Boring Nos. B-1 through B-

4) were drilled and sampled on March 9, 2021 at the locations as shown on Plate No. 2.

Drilling, sampling, and testing were performed in accordance with applicable ASTM procedures using a tractor-mounted drill rig and conventional auger drilling methods. Soil sampling during the drilling of the geotechnical borings consisted of continuous sampling to a depth of 12 feet and on 5-foot intervals thereafter with disturbed samples being obtained.

Disturbed samples of soil were taken through the flight auger of the sampler or in conjunction with standard penetration test procedures. The standard penetration test (SPT) blow count is defined as the number of SPT hammer blows that are required to advance a split spoon sampler 1 foot into the soil. One SPT hammer blow consists of a 140-pound hammer free

April 12, 2021 Page: 12 falling for a distance of 30 inches. The results of the standard penetration test provide a basis for estimating the relative strength and compressibility of the soil profile components.

The samples recovered were removed from the flight auger of the sampler or the split spoon sampler and placed into airtight plastic bags.

All samples were transported to All-Terra laboratory for purposes of performing laboratory tests on selected samples.

3.0 LABORATORY TESTING

For the current geotechnical study, a laboratory testing program was conducted to obtain engineering properties for use in performing engineering analyses and to adjust field soil classifications. The following laboratory tests were performed:

LABORATORY TEST TEST STANDARD

Moisture Content of Soils ASTM D 2216

Percent Soil Particles Passing a No. 200 Sieve ASTM D 1140

Liquid Limit, Plastic Limit, and Plasticity Index of Soils ASTM D 4318

The number of tests and the test results are presented in the attached boring logs for Boring Nos. B-1 through B-4 in the Appendix. All tests were performed in accordance with applicable ASTM procedures and methods and soil classifications were completed in accordance with the procedures and guidelines of ASTM D 2487 and ASTM D 2488.

4.0 FOUNDATION MAINTENACE

Differential movements usually result from non-uniform changes in soil moisture that may result from climatic and non-climatic factors. Design methods for slab-on-grade construction consider only climatic factors and are based on average climatic conditions being present before construction and throughout the structure life. Maintaining balanced soil moisture conditions throughout the life of the structure reduces the potential for differential movements.

Factors unrelated to climate may result in soil movements that may be greater than those resulting only from climatic influence. The presence or absence of many non-climatic factors is generally beyond the direct influence of the design team. The non-climatic factors are often manifested during the structure life.

Non-climatic factors that affect soil moisture include trees (present and removed) and landscaping, inadequate or altered drainage during the structure life, and the availability of moisture from unplanned sources such as roof drains, air conditioning drains, or below-

April 12, 2021 Page: 13 grade utility or irrigation system leaks. Non-climatic factors and their potential effects on structure performance are discussed in the following paragraphs.

Trees and Landscaping

Trees and other landscaping have dynamic effects on soil moisture content. As a tree or other landscaping grows and matures, an increasing amount of moisture is needed to sustain its growth. If sufficient moisture in unavailable from infiltration of water from the surface, either through rainfall or irrigation, the moisture within the soil becomes the available source resulting in decreases in the soil moisture content and soil shrinkage adjacent to trees. The lower moisture contents generally are observed throughout the area of influence of the tree's root system. The lateral extent where moisture changes occur is generally taken as canopy width of the tree.

A uniform reduction in moisture usually does not occur; the changes in moisture content are often greatest near the tree and decrease with distance from the tree. The vertical extent of moisture changes caused by trees is not well defined since little information is known about the suction potential of trees in the area. From forensic investigations, the depth of influence appears to extend below 6 feet to 8 feet and may extend to 12-foot to 15-foot depths for large, mature trees. Trees should be located a distance away from the foundation at least equal to the mature height of the tree. Tree selection should consider the water capacity needed to sustain a mature tree. Irrigation systems may not be effective in supplying sufficient water for growth.

Drainage for Structures

Improper drainage can have significant negative effects on structure performance, especially if the structure was constructed during or immediately after a dry period. The following are general notes concerning proper drainage considerations:

Positive drainage away from the structure must be designed, constructed, and maintained throughout the structure life.

Landscaping systems must be laid out to provide/maintain positive drainage away from the structure and not permit water to impound adjacent to the structure.

Downspouts from roof drainage systems should be designed to discharge water away from the structure foundation.

Drainage for Pavements

Drainage is an important structural characteristic which affects the predicted performance of a pavement system. A Cd value of 1.0 is typically used as an input parameter for pavements. A Cd value of 1.0 corresponds to 'Good Drainage'. AASHTO defines 'Good Drainage' as "the ability to remove water from the pavement within one (1) day".

Therefore, “proper drainage maintenance” is necessary to ensure continued 'Good

April 12, 2021 Page: 14

Drainage' and minimize the inundation and weakening of the subgrade soils under the proposed pavements.

5.0 CONSTRUCTION CONSIDERATIONS

The following recommendations should be followed with regard to construction of the proposed development:

Fill material and fill compaction should comply with the recommendations provided in Section 1.3.1 of this report.

Construction operations should be monitored by a representative of the design engineer/owner/geotechnical engineer.

Materials testing should be performed to assure that acceptable materials and construction methods are provided by the contractor.

6.0 CLOSING REMARKS

All-Terra Engineering, Inc. has performed a geotechnical investigation pertaining to the design and construction of the proposed headquarter and shop buildings as well as the associated pavements that are being planned/designed for construction at 1206 APC NWR Road in Eagle Lake, Texas. This report has been prepared for the exclusive use of US Fish and Wildlife Service and its authorized representatives in accordance with generally accepted soil and foundation engineering practices. No other warranty, expressed or implied, is made.

In the event that changes are made in the nature, design, or location of the proposed development, the conclusions, parameters, and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the findings/recommendations of this report are modified or verified in writing. The analyses and recommendations presented in this report are based upon data obtained from 4 geotechnical borings drilled on March 9, 2021. The nature and extent of variations within the subsurface materials may not become evident until after construction is initiated. If significant variations in the subsurface materials are encountered during construction, it may be necessary to re-evaluate the recommendations provided in this report.

APPENDIX

Plate Nos. 1 through 7

04/09/21

Project No:

AE21-1056

Plate No. 16200 Rothway, Ste 140 Houston, Texas 77040 Date:

Proposed Headquarter and Shop Buildings 1206 APC NWR Road Eagle Lake, Texas 77434

VICINITY MAP

SITE LOCATION

6200 Rothway, Ste 140 Houston, Texas 77040 Date: 04/09/21 LOCATIONS OF BORINGS Plate No. 2

Proposed Headquarter and Shop Buildings Project No:

1206 APC NWR Road AE21-1056Eagle Lake, Texas 77434

- Geotechnical borings drilled for the study.

B-4

B-3

B-2B-1

PROJECT: Proposed Headquarter and Shop Buildings BORING NO.: B-1 BORING LOCATION: See Plate No. 2

PROJECT LOCATION: 1206 APC NWR Road BORING TYPE: Auger:

Eagle Lake, Texas 77434 APPROX. ELEVATION: ft-MSL

PROJECT NO.:

CLIENT: US Fish and Wildlife Service DATE:

LL PL PI

POORLY GRADED SAND WITH

1 SILT (SP-SM), loose to medium dense, brown

- tan at 2'

10 4'

SILTY SAND (SM), loose, tan

- no recovery at 18'

20 20'

GPS Coordinates of Boring:

Non-Plastic

J

J

10.8

17.0

5-5-6 15.8

8.3

3-5-6 8.4

7.5 6.8Non-Plastic

March 9, 2021

D R Y D

EN

SI

TY

(P C F)

PA

SS

#2

SI

EV

E, C O M

PR

ES

SI

VE

ST

R

EN

G

TH

(T

SF

NA

AE21-1056

D

EP

TH

,F T.

SA

M

PL

E

G R O U N D W

AT

ER

SO

IL

TY

PE

LOG OF BORING

H

AN

D

PE

N

R

EA

D

IN

G (T

SF

SP

T

BL

O W S

(P

ER

6"

M O

IS

TU

R E

C O N

TE

N T, DESCRIPTION OF STRATUM

ATTERBERG LIMITS

5-5-5 16.1

5-6-6 16.3

19.8J

( Boring terminated at 20' ) N 29.881478º / W -95.436441º

Groundwater = 8.5' during drilling and the boring caved at a depth of 8.0' approx. 15 minutes after drilling completion. The boring was backfilled w/ soil cuttings after the drilling activities. Plate No. 3

PROJECT: Proposed Headquarter and Shop Buildings BORING NO.: B-2

PROJECT LOCATION: 1206 APC NWR Road BORING TYPE: Auger:

Eagle Lake, Texas 77434 APPROX. ELEVATION: ft-MSL

PROJECT NO.:

CLIENT: US Fish and Wildlife Service DATE:

LL PL PI

POORLY GRADED SAND WITH

1 SILT (SP-SM), loose, tan and brown

4 4'

SILTY SAND (SM), loose to medium 5 dense, tan

15 15'

20 20'

GPS Coordinates of Boring:

J

J

Non-Plastic

Non-Plastic

J

23.0

25.04-6-6 17.5

4-5-7 13.9

5-4-4 5.8

6.0

NA

AE21-1056

PA

SS

#2

SI

EV

E, D R Y D

EN

SI

TY

(P C F)

C O M

PR

ES

SI

VE

ST

R

EN

G

TH

(T

SF

LOG OF BORING

March 9, 2021

SP

T

BL

O W S

(P

ER

6"

M O

IS

TU

R E

C O N

TE

N T, ATTERBERG LIMITS

D

EP

TH

,F T.

SA

M

PL

E

G R O U N D W

AT

ER

SO

IL

TY

PE

DESCRIPTION OF STRATUM

H

AN

D

PE

N

R

EA

D

IN

G (T

SF

28.4

5-5-7 16.4

17.9

J 17.1

Groundwater = 8.0' during drilling and the boring caved at a depth of 8.0' approx. 15 minutes after drilling completion. The boring was backfilled w/ soil cuttings after the drilling activities. Plate No. 4

N 29.881512º / W -95.436220º

PROJECT: Proposed Headquarter and Shop Buildings BORING NO.: B-3

PROJECT LOCATION: 1206 APC NWR Road BORING TYPE: Auger:

Eagle Lake, Texas 77434 APPROX. ELEVATION: ft-MSL

PROJECT NO.:

CLIENT: US Fish and Wildlife Service DATE:

LL PL PI

SILTY SAND (SM), loose to medium 1 dense, brown

4 4'

POORLY GRADED SAND WITH

5 SILT (SP-SM), medium dense, brown

8 8'

SILTY SAND (SM), loose, brown

20 20'

GPS Coordinates of Boring:

Groundwater = 9.0' during drilling and the boring caved at a depth of 8.5' approx. 15 minutes after drilling completion. The boring was backfilled w/ soil cuttings after the drilling activities. Plate No. 5

N 29.881512º / W -95.436220º

Non-Plastic

Non-Plastic

J 17.0

J 18.0

J 18.6

5-6-7 17.8 24.3

10.7

4-6-6 13.8

4-6-6 13.8

15.3

5-5-7 4.0

J 4.5

SP

T

BL

O W S

(P

ER

6"

M O

IS

TU

R E

C O N

TE

N T, ATTERBERG LIMITS

PA

SS

#2

SI

EV

E, D R Y D

EN

SI

TY

(P C F)

C O M

PR

ES

SI

VE

ST

R

EN

G

TH

(T

SF

D

EP

TH

,F T.

SA

M

PL

E

G R O U N D W

AT

ER

SO

IL

TY

PE

DESCRIPTION OF STRATUM

H

AN

D

PE

N

R

EA

D

IN

G (T

SF

LOG OF BORING

NA

AE21-1056

March 9, 2021

PROJECT: Proposed Headquarter and Shop Buildings BORING NO.: B-4

PROJECT LOCATION: 1206 APC NWR Road BORING TYPE: Auger:

Eagle Lake, Texas 77434 APPROX. ELEVATION: ft-MSL

PROJECT NO.:

CLIENT: US Fish and Wildlife Service DATE:

LL PL PI

POORLY GRADED SAND WITH

1 SILT (SP-SM), loose to medium dense, dark brown

4 4'

SILTY SAND (SM), loose to medium 5 dense, tan

- no recovery at 18'

20 20'

GPS Coordinates of Boring:

Groundwater = 8.5' during drilling and the boring caved at a depth of 8.0' approx. 15 minutes after drilling completion. The boring was backfilled w/ soil cuttings after the drilling activities. Plate No. 6

N 29.881512º / W -95.436220º

J 18.8

J 15.5 13.0

6-6-7 16.3

5-6-6 15.2 Non-Plastic 12.6

4-5-7 15.1

5-6-6 6.5 Non-Plastic

J 9.3

SP

T

BL

O W S

(P

ER

6"

M O

IS

TU

R E

C O N

TE

N T, ATTERBERG LIMITS

PA

SS

#2

SI

EV

E, D R Y D

EN

SI

TY

(P C F)

C O M

PR

ES

SI

VE

ST

R

EN

G

TH

(T

SF

D

EP

TH

,F T.

SA

M

PL

E

G R O U N D W

AT

ER

SO

IL

TY

PE

DESCRIPTION OF STRATUM

H

AN

D

PE

N

R

EA

D

IN

G (T

SF

LOG OF BORING

NA

AE21-1056

March 9, 2021

Slickensided ------- Having planes of weakness that appear slick and glossy. The degree of slickensidedness depends upon the spacing of slickensides and the ease of breaking along these planes.

Fissures ------------- Containing shrinkage or relief cracks, often filled with fine sand or silt; usually more or less vertical.

Pocket --------------- Inclusion of material of different texture that is smaller than the diameter of the sample.

Parting --------------- Inclusion less than 1/8 inch thick extending through the sample. NO JAR Seam ----------------- Inclusion 1/8 inch to 3 inches thick extending through the sample. SAMPLE SAMPLE Layer ----------------- Inclusion greater than 3 inches thick extending through the sample.

Laminated ---------- Soil sample composed of alternating partings or seams of different soil types.

Interlayered---------- Soil sample composed of alternating layers of different soil types.

Intermixed ---------- Soil sample composed of pockets of different soil types and layered or laminated structure is not evident. SHELBY SPT Calcareous--------- Having appreciable quantities of carbonate. TUBE

Number of blows for each 6-inch increment of split spoon penetration.

Number of blows of split spoon penetration for the indicated depth of penetration in inches.

MAJOR LETTER TYPICAL

DIVISIONS SYMBOL DESCRIPTIONS

GRAVEL & CLEAN WELL GRADED GRAVEL, GRAVEL-SAND Degree Plasticity Index COARSE GRAVELY GRAVEL MIXTURES WITH LITTLE OR NO FINES None - - - - - - 0 - 4 GRAINED SOILS (LITTLE OR POORLY GRADED GRAVEL, GRAVEL-SAND Slight - - - - - - 5 - 10

SOILS LESS THAN NO FINES) MIXTURES WITH LITTLE OR NO FINES Medium - - - - - - 11 - 20 LESS 50% PASSING W/ APPRECIABLE SILTY GRAVEL, GRAVEL-SAND-SILT MIXTURES High - - - - - - 21 - 40 THAN NO. 4 SIEVE FINES GC CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES Very High - - - - - - > 40

50% SANDS CLEAN SANDS SW WELL GRADED SAND, GRAVELY SAND (LITTLE FINES)

PASSING MORE THAN LITTLE FINES SP POORLY GRADED SANDS, GRAVELY SAND (L.FINES)

NO. 200 50% PASSING SANDS WITH SM SILTY SANDS, SAND-SILT MIXTURES Very Soft - - - - - - < 0.25 ksf SIEVE NO. 4 SIEVE APPRECIABLE FINES SC CLAYEY SANDS,SAND-CLAY MIXTURES Soft - - - - - - ksf

INORGANIC SILTS & VERY FINE SANDS,ROCK FLOUR Firm - - - - - - ksf FINE SILTS AND CLAYS SILTY OR CLAYEY FINE SANDS OR CLAYEY SILT W/ LOW PI Stiff - - - - - - ksf

GRAINED LIQUID LIMIT INORGANIC CLAY OF LOW TO MEDIUM PI LEAN CLAY Very Stiff - - - - - - ksf SOILS LESS THAN 50 GRAVELY CLAYS, SANDY CLAYS, SILTY CLAYS Hard - - - - - - ksf

LESS OL ORGANIC SILTS & ORGANIC SILTY CLAYS OF LOW PI

THAN INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS

50% SILTS AND CLAYS FINE SANDY OR SILTY SOILS, ELASTIC SILTS

PASSING LIQUID LIMIT INORGANIC CLAYS OF HIGH PLASTICITY

NO. 200 50 OR GREATER FAT CLAYS SPT (bpf) SIEVE OH ORGANIC CLAYS OF MED TO HIGH PI, ORGANIC SILT Very Loose 0 - 4 0 - 0.50

PEAT AND Loose 5 - 10 0.50 - 1.50 OTHER HIGHLY ORGANIC SOILS Med. Dense 11 - 30 1.50 - 4.00

Dense 31 - 50 Very Dense > 50

3/4"

BOUL- GRAVEL SAND

-DERS

152 76.2 19.1 4.76 2.0 0.42 0.074

NOTES:

The boring logs and related information depict subsurface conditions only at the specific locations and dates indicated. Soil conditions and water levels at other locations may differ from conditions occuring at these boring locations. Also the passage of time may result in a change in the conditions at these boring locations.

REFERENCES:

(1) Soil Mechanics in Engineering Practice, Terzhagi and Peck, 1967

(2) ASTM D 422

0.005 0.001

GRAIN SIZE IN MM

Plate No. 7

No.200

COBBLES SILT CLAYCOARSE FINE COARSE MEDIUM FINE

bpf = blows/ft

CLASSIFICATION OF GRANULAR SOILS (2)

U.S. STANDARD SIEVE SIZE(S)

6" 3" No.4 No.10 No.40

CH Density/Consistency PP (tsf)

HIGHLY ORGANIC SOIL PT

UNCLASSIFIED FILL MATERIALS ARTIFICIALLY DEPOSITED AND OTHER UNCLASSIFIED SOILS AND MANMADE

SOIL MIXTURES

4.00 - 4.50 > 4.50

CL

2.00 - 4.00

> 4.00

MH GRANULAR SOILS (1)

B) Unconfined Compressive Strength

0.25 - 0.50

ML

0.50 - 1.00

1.00 - 2.00

UNIFIED SOIL CLASSIFICATION SYSTEM - ASTM D 2487

COHESIVE SOILS (1)

A) Degree of Plasticity

GW

GP

GM

SPLIT-SPOON SAMPLER DRIVING RECORD GROUNDWATER DATA

Blows Per Foot Water Level after 24 hours.8-10-12

50/5" Water level during drilling.

TERMS AND SYMBOLS USED ON BORING LOGS

SOIL STRUCTURE SAMPLER TYPE

J