Atch 7 Repair Transient Parking Ramp Geotechnical Report 96 pages 20190612.pdf

REPORT COVER PAGE

Geotechnical Engineering Report

Reconstruction of Transient Apron Marietta, Cobb County, Georgia

June 12, 2019 Terracon Project No. 49185336

Prepared for:

Mead & Hunt

Denver, Colorado

Prepared by:

Terracon Consultants, Inc.

Atlanta, Georgia

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REPORT TOPICS

INTRODUCTION

SITE CONDITIONS

PROJECT DESCRIPTION

GEOTECHNICAL CHARACTERIZATION

GEOTECHNICAL OVERVIEW

EARTHWORK

PAVEMENTS

GENERAL COMMENTS

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

ATTACHMENTS

EXPLORATION AND TESTING PROCEDURES

SITE LOCATION AND EXPLORATION PLANS

EXPLORATION RESULTS

SUPPORTING INFORMATION

Note: Refer to each individual Attachment for a listing of contents.

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INTRODUC TION

Geotechnical Engineering Report Reconstruction of Transient Apron

Dobbins Air Reserve Base Marietta, Cobb County, Georgia

Terracon Project No. 49185336 June 12, 2019

INTRODUCTION

This report presents the results of our subsurface exploration and geotechnical engineering services performed for the proposed reconstruction of transient apron located at Dobbins Air Reserve Base in Marietta, Cobb County, Georgia. The purpose of these services is to provide information and geotechnical engineering recommendations relative to:

■ Subsurface soil conditions ■ Groundwater conditions

■ Site preparation and earthwork ■ Pavement design and construction

■ Excavation considerations

The geotechnical engineering Scope of Services for this project included the advancement of 20 test borings to depths of 10 feet below existing site grades.

Maps showing the site and boring locations are shown in the Site Location and Exploration Plan sections, respectively. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included on the boring logs in the Exploration Results section.

SITE CONDITIONS

The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps.

Item Description

Parcel Information

The project is located at Dobbins Air Reserve Base in Marietta, Cobb County, Georgia.

55,196 square yards (496,764 square feet) Approximate Coordinates: 33.917333°N / -84.51176°W (See Site Location)

Existing Improvements Existing aircraft parking apron.

Reconstruction of Transient Apron Marietta, Cobb County, Georgia June 12, 2019 Terracon Project No. 49185336

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Item Description

Current Ground Cover

Concrete pavement. According to the provided Airfield Pavement Evaluation the existing concrete pavement has a joint spacing on an approximately 25’ x 25’ grid with thicknesses ranging from about 7 ½” to 15 ½” in the Transient Apron area.

Existing Topography Relatively level Geology Piedmont

PROJECT DESCRIPTION

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

GEOTECHNICAL CHARACTERIZATION

Site Geology

The project site is located in the Piedmont Physiographic Province of Georgia which is characterized by medium to high grade metamorphic rocks and scattered igneous intrusions. The term metamorphic describes rocks that have been subjected to high temperatures and/or pressures, usually deep within the earth’s crust. These high temperatures and pressures cause the textural and mineralogical characteristics of the original rock to be altered and can also cause certain rock types to fully melt, becoming what is known as magma. Magma is less dense than the surrounding solidified rock and tends to move upward through fractures and joints, displacing the surrounding rock. This rock type is known as an igneous intrusion. Metamorphic rocks are

Item Description

Information Provided Our understanding of the project is based upon email correspondence and telephone conversations with you, as well as our site visits.

Electronic files were provided in various emails describing existing conditions, required scope of work, and access requirements.

Project Description The project encompasses the reconstruction of approximately 55,196 square yards of rigid airfield pavement designated as the Transient Apron.

Pavement Construction

The proposed replacement pavement section consists as follows:

■ 17 inches PCC

■ 6 inches stabilized drainage layer

■ 6 inches of subgrade material compacted to 100% modified

Proctor

■ Up to 24 inches of underlying material compacted to 95% modified

Proctor Joint spacing is 20 feet x 20 feet.

Grading Expected to match existing grades Below-Grade Areas None anticipated

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Responsive Resourceful Reliable 4 predominant in this region but, due to erosion and uplift, both of these rocks will eventually become exposed at the land surface.

The subsurface bedrock in this region has undergone differing rates of weathering, which often produces a considerable variation in depth to competent rock over short horizontal distances. It is also not unusual for lenses and boulders of hard rock and zones of partially weathered rock to be present within the soil mantle above the general bedrock level. The typical residual soil profile consists of clayey soils near the surface, where soil weathering is more advanced, underlain by sandy silts and silty sands, which often consist of saprolites (native soils which maintain the original fabric of the parent rock). Generally, the soil becomes harder with depth to the top of parent crystalline rock or “massive bedrock” which occurs at depth.

The boundary between soil and rock is typically not sharply defined. A transitional zone termed "partially weathered rock" is normally found overlying bedrock. Partially weathered rock (PWR) is defined for engineering purposes as residual material with a standard penetration resistance exceeding 100 blows per foot (bpf).

According to “Geology of the Greater Atlanta Region” by McConnell and Abrams, Department of Natural Resources, Environmental Protection Division, Georgia Geologic Survey, Bulletin 96, 1984, the site is underlain by biotic gneiss, mica schist, and amphibolite.

Typical Subsurface Profile

The borings drilled at the site generally encountered layer of concrete pavement underlain by residual soils.

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

Description Approximate Depth to Bottom of Stratum

Material Encountered Consistency/Density

Stratum 11 6 to 20 inches Concrete --

Stratum 2 To Boring Termination Depth of 10 feet

RESIDUUM –

Sandy SILT (ML)

Silty SAND (SM)

Medium Stiff to Very Stiff

Very Loose to Medium Dense

1. A layer of topsoil was encountered in Borings B-16 and B-20 at thicknesses of 3 and 6 inches, respectively.

Laboratory tests were conducted on selected soil samples and the test results are presented in Exploration Results. We conducted moisture content test, grain size analysis, Atterberg limits, standard proctor compaction, corrosivity series tests, and California Bearing Ratio (CBR) for four

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Responsive Resourceful Reliable 5 samples obtained by combining auger cuttings from several borings. The results are presented in Exploration Results. Specific conditions encountered at each boring location are indicated on the individual boring 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.

Infiltration Testing Results

The in-situ infiltration testing was performed using the Aardvark infiltration testing equipment. See Exploration Results for the attached report that describes the testing along with the data and results. The results are summarized here:

Test Location INF-1: Testing at approximately 5 feet below the existing ground surface. Testing was performed within residual soils. The measured in-place, saturated hydraulic conductivity (KSAT) value is 0.47 inch per hour.

Test Location INF-2: Testing at approximately 5 feet below the existing ground surface. Testing was performed within residual soils. The measured KSAT value is 0.78 inch per hour

Groundwater

The boreholes were observed while drilling and after completion for the presence and level of groundwater. Groundwater was not observed in the borings while drilling, or for the short duration that the borings were allowed to remain open. However, this does not necessarily mean the borings terminated above groundwater. Long term observations in piezometers or observation wells sealed from the influence of surface water are often required to define groundwater levels in materials of this type.

Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. In addition, perched water can develop over low permeability soil or rock strata. Therefore, groundwater levels during construction or at other times in the life of the pavement may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project.

GEOTECHNICAL OVERVIEW

The purpose of this study was to assess general subsurface conditions relative to their potential impact on the proposed development. We advanced twenty borings in the existing Transient Apron and performed two infiltration tests. We visually classified soils in accordance with the United Soil Classification system (USCIS) and performed laboratory tests in accordance with Chapter 5 of UFC 3-260-02.

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There was a presence of 6 to 20 inches of concrete pavement in the borings. The concrete layer was underlain by residual soil consisting of sandy SILTS (ML) and silty SANDS (SM) with standard penetration resistance (N) values ranging from 2 to 22 blows per foot.

The moisture content of the samples obtained ranged from 14.4% to 28.8%, which was 0% to 13% higher than the samples optimum moisture. We recommend proof-rolling the exposed subgrade prior to drainage layer placement. Drying of these soils may be needed depending upon the moisture contents and behavior under proof-roll at the time of construction. Drying is typically performed by disc harrow or bulldozer/motor grader blade to turn the soils. Any unstable areas should be undercut and replaced or stabilized in place. We recommend using modified proctor test to determine the dry density and optimum water content of soils being used as fill. Refer to earthwork section for more specific details regarding fill.

Liquid Limit (LL) of the samples ranged from 46 to 50, and the Plasticity Index (PI) ranged from 15 to 20. According to UFC 3-260-02, LL>40 and PI>15 are considered as expansive soils. However, based upon our experience the residual soils in this area is not susceptible to swell and shrinkage.

The corrosivity tests indicated that the soils can be moderately corrosive to cast/ductile iron, and very corrosive to steel. The risk of corrosion can be mitigated by ensuring proper concrete coverage is maintained around the steel reinforcing.

Upon reviewing the results obtained from laboratory test results of the California Bearing Ratio, we recommend a CBR value of 4 for pavement design. This CBR value corresponds to a k value of 125 pci.

The General Comments section provides an understanding of the report limitations.

EARTHWORK

Earthwork is anticipated to include removal of concrete pavement, grubbing and fill placement.

Installation of underground storm water drainage lines may be included as part of the reconstruction effort. The following sections provide recommendations for use in the preparation of specifications for the work

Earthwork on the project should be observed and evaluated by a qualified geotechnical engineer.

The evaluation of earthwork should include observation and testing of engineered fill, subgrade preparation, foundation bearing soils, and other geotechnical conditions exposed during the construction of the project.

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Site Preparation

We anticipate construction will be initiated by removing existing concrete pavement. Engineered fill can be placed to bring the subgrade up to the design elevations.

Prior to performance of any excavation, all underground utilities should be identified, and the depth of these utilities determined to avoid potential conflicts. If needed, the utilities should be rerouted or deepened.

The fine-grained soils encountered in the borings will be sensitive to disturbance from construction activity and water seepage. If precipitation occurs prior to or during construction, the near-surface silty soils could increase in moisture content and become more susceptible to disturbance.

Construction activity should be monitored and curtailed if the construction activity is causing subgrade disturbance. A qualified geotechnical engineer can help with monitoring and developing recommendations to aid in limiting subgrade disturbance.

The topsoil layer encountered beneath the pavement section in Borings B-16 and B-20 should be removed during pavement demolition and subgrade preparation operations. Any existing fills that may be associated with underground utilities should also be evaluated at the time of construction to assess if undercutting and replacement or in-place stabilization is necessary. We recommend a contingency be carried in the contact for undercutting and replacement of unstable materials if they are encountered.

After stripping, the exposed subgrade should be proof-rolled with heavy rubber tire construction equipment such as a fully loaded tandem-axle dump truck. A qualified geotechnical engineer or his representative should observe proof-rolling to aid in locating unstable subgrade materials.

Proof-rolling should be performed after a suitable period of dry weather to avoid degrading an otherwise acceptable subgrade and to reduce the amount of undercutting / remedial work required. Unstable materials identified should be stabilized as directed by the engineer based on conditions observed during construction. Undercut and replacement and densification in-place are typical remediation methods.

Excavation Conditions

After comparison of the boring data and the proposed finished grades, we do not anticipate that materials requiring difficult excavation techniques will be encountered during mass grading operations. The encountered residual soils should be excavatable with conventional backhoes, front-end loaders, and tracked excavators.

Groundwater Conditions

Groundwater was not encountered in any of the borings during our exploration. Based on our understanding of the proposed development, we do not expect groundwater to affect construction. If

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Responsive Resourceful Reliable 8 groundwater is encountered during construction, some form of temporary or permanent dewatering may be required. Conventional dewatering methods, such as pumping from sumps, should likely be adequate for temporary removal of any groundwater encountered during excavation at the site. Well points would likely be required for significant groundwater flow, or where excavations penetrate groundwater.

Fill Material Types

Fill required to achieve design grade should be classified as structural fill and general fill.

Structural fill is material used below, or within 10 feet of pavements. General fill is material used to achieve grade outside of these areas. Soils used for structural and general fill should meet the following material property requirements:

Soil Type 1,2,3 USCS Classification Acceptable Parameters (for Structural Fill)

Fine Grain CL and ML

LL < 45 / PI < 25

Less than 25% retained on No. 200 sieve

Granular SP, SM, SC, and SW Note specific parameters here if any

On-Site Soils SM and ML Drying of on-site soils may be needed. In-situ moisture should be verified at the time of construction.

1. Structural and general fill should consist of approved materials free of organic matter, debris, and particles larger than about 4 inches. Frozen material should not be used, and fill should not be placed on a frozen subgrade. A sample of each material type should be submitted to the Geotechnical Engineer for evaluation prior to use on this site.

2. All fill should have a maximum dry density of at least 95 pounds per cubic foot (pcf) as determined by the modified Proctor test (ASTM D1557).

3. Any materials proposed as fill from off-site sources should be tested for compliance with these criteria before being hauled to the site.

Fill Compaction Requirements

Structural and general fill should meet the following compaction requirements.

Material Type and Locations1,2 Minimum Compaction Requirement (%)

Range of Moisture Contents for Compaction3

Minimum Maximum Per the Modified Proctor Test (ASTM D 1557)

Acceptable soil or approved imported fill soils:

Beneath pavements: 95 -2% +3% 12 inches directly below pavements: 98 -2% +3%

Per the Modified Proctor Test (ASTM D 1557)

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Aggregate base (beneath pavements) 98 -3% +3%

1. Engineered fill materials should be placed in horizontal, loose lifts not exceeding 9 inches in thickness and should be thoroughly compacted. Where light compaction equipment is used, as is customary within a few feet of retaining walls and in utility trenches, the lift thickness may need to be reduced to achieve the desired degree of compaction. Soils removed which will be used as engineered fill should be protected to limit an increase in moisture content due to rain.

2. We recommend that engineered fill be tested for moisture content and compaction during placement. Should the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved.

3. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to be achieved without pumping when proof-rolled. Based on the laboratory testing soils appear to be were wet of their optimum moisture content. Therefore, some moisture conditioning should be expected during fill placement and subgrade preparation.

Grading and Drainage

Adequate positive drainage should be provided during construction and maintained throughout the life of the project to prevent an increase in moisture content of the pavement and backfill materials. Surface water drainage should be controlled to prevent undermining of fill slopes and structures during and after construction.

Earthwork Construction Considerations

Upon completion of filling and grading, care should be taken to maintain the subgrade water content prior to construction of pavement. Construction traffic over the completed subgrades should be avoided. The site should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. Water collecting over or adjacent to construction areas should be removed. If the subgrade freezes, desiccates, saturates, or is disturbed, the affected material should be removed, or the materials should be scarified, moisture conditioned, and recompacted prior to floor slab construction.

Surface water should not be allowed to pond on the site and soak into the soil during construction.

Construction staging should provide drainage of surface water and precipitation away from the building and pavement areas. Any water that collects over or adjacent to construction areas should be promptly removed, along with any softened or disturbed soils. Surface water control in the form of sloping surfaces, drainage ditches and trenches, and sump pits and pumps will be important to avoid ponding and associated delays due to precipitation and seepage.

All excavations should be sloped or braced as required by Occupational Safety and Health Administration (OSHA) regulations to provide stability and safe working conditions. Temporary excavations will probably be required during grading operations. The grading contractor, by his contract, is usually responsible for designing and constructing stable, temporary excavations and should shore, slope or bench the sides of the excavations as required to maintain stability of both

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Responsive Resourceful Reliable 10 the excavation sides and bottom. All excavations should comply with applicable local, state and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards.

Construction site safety is the sole responsibility of the contractor who controls the means, methods, and sequencing of construction operations. Under no circumstances shall the information provided herein be interpreted to mean Terracon is assuming responsibility for construction site safety, or the contractor's activities; such responsibility shall neither be implied nor inferred.

Construction Observation and Testing

The earthwork efforts should be monitored under the direction of the Geotechnical Engineer.

Monitoring should include documentation of adequate removal of pavement, proof-rolling, and mitigation of unstable areas delineated by the proof-roll.

Each lift of compacted fill should be tested, evaluated, and reworked, as necessary, until approved by the Geotechnical Engineer or his representative prior to placement of additional lifts. In addition to the documentation of the essential parameters necessary for construction, the continuation of the Geotechnical Engineer into the construction phase of the project provides the continuity to maintain the Geotechnical Engineer’s evaluation of subsurface conditions, including assessing variations and associated design changes.

PAVEMENTS

Recommended CBR Value

Pavement design is not within the scope of this report. After analyzing the test data, we recommend a CBR value of 4 for use in pavement design. The CBR value corresponds to a k value of 125 pci. The CBR value is based upon the modified Proctor compaction test in accordance with UFC 3-260-02.

Shrink / Swell Potential

Liquid Limit (LL) of the samples ranged from 46 to 50, and the Plasticity Index (PI) ranged from 15 to 20. According to UFC 3-260-02, LL>40 and PI>15 are considered as expansive soils. However, based upon our experience the residual soils in this area is not susceptible to swell and shrinkage.

Therefore, the potential for shrinkage and swelling of the subgrade residual soils when wetted and dried is expected to be low.

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Corrosivity

The corrosivity tests indicated that the soils can be moderately corrosive to cast/ductile iron, and very corrosive to steel. The risk of corrosion can be mitigated by ensuring proper concrete coverage is maintained around the steel reinforcing.

Aggregate Reactivity

Our experience indicates that the granite and amphibolite aggregate used in concrete in the northwest part of the state are more or less chemically inert. In addition to our experience, we also reviewed the GDOT Qualified Products List for aggregate suppliers. The magnesium sulfate soundness test is part of the battery of tests on the supplier’s aggregate samples. Magnesium sulfate soundness test results on Group II aggregates (granite and amphibolite) from quarries for various suppliers (Vulcan, Martin Marietta, etc.) showed aggregate loss in the range of 0.2% to 1%.

Therefore, we consider the granite and amphibolite aggregate from nearby quarries that will likely be used in the concrete pavement to have a low reactivity.

Pavement Drainage

Pavements should be sloped to provide rapid drainage of surface water. Water allowed to pond on or adjacent to the pavements could saturate the subgrade and contribute to premature pavement deterioration. In addition, the pavement subgrade should be graded to provide positive drainage within the granular base section. Appropriate sub-drainage or connection to a suitable daylight outlet should be provided to remove water from the granular subbase.

Based on the possibility of shallow and/or perched groundwater, we recommend installing a pavement subdrain system to control groundwater, improve stability, and improve long-term pavement performance.

Pavement Maintenance

Preventive maintenance should be planned and provided for through an on-going pavement management program. Maintenance activities are intended to slow the rate of pavement deterioration and to preserve the pavement investment. Maintenance consists of both localized maintenance (e.g., crack and joint sealing and patching) and global maintenance (e.g., surface sealing). Preventive maintenance is usually the priority when implementing a pavement maintenance program. Additional engineering observation is recommended to determine the type and extent of a cost-effective program. Even with periodic maintenance, some movements and related cracking may still occur, and repairs may be required.

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GENERAL COMMENTS

Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Natural variations will occur between exploration point locations or due to the modifying effects of construction or weather.

The nature and extent of such variations may not become evident until during or after construction.

Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations.

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

Our services and any correspondence or collaboration through this system are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third-party beneficiaries intended. Any third-party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client.

Reliance upon the services and any work product is limited to our client, and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. No warranties, either express or implied, are intended or made.

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

Site safety, and cost estimating including, excavation support, and dewatering requirements/design are the responsibility of others. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing.

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ATTACHMENTS

June 12, 2019 Terracon Project No. 49185336

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EXPLORATION AND TESTING PROCEDURES

Field Exploration

Number of Borings Boring Depth (feet) Planned Location

20 10 or auger refusal pavement

Boring Layout and Elevations: Borings were field located using survey techniques by Lowe Engineers working under the direction of Mead & Hunt. Elevations were obtained by interpolating between the contours on the provided topographic plan.

Subsurface Exploration Procedures: We advanced the borings with a track-mounted rotary drill rig using continuous flight hollow stem augers. Four samples were obtained in the upper 10 feet of each boring. In the split-barrel sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon was driven into the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value.

The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths. Several bulk samples were obtained from the auger cuttings for laboratory testing. We observed and recorded groundwater levels during drilling and sampling. For safety purposes, all borings were backfilled with auger cuttings after their completion. Pavements were patched with concrete as appropriate.

The sampling depths, penetration distances, and other sampling information was recorded on the field boring logs. The samples were placed in appropriate containers and taken to our soil laboratory for testing and classification by a Geotechnical Engineer. Our exploration team prepared field boring logs as part of the drilling operations. These field logs included visual classifications of the materials encountered during drilling and our interpretation of the subsurface conditions between samples. Final boring logs were prepared from the field logs. The final boring logs represent the Geotechnical Engineer's interpretation of the field logs and include modifications based on observations and tests of the samples in our laboratory.

Laboratory Testing

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

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■ ASTM D2216 Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

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

■ ASTM D422 Standard Test Method for Particle-Size Analysis of Soils

■ ASTM D1557 Modified Proctor

■ ASTM D1883 California Bearing Ratio

■ Corrosivity series tests (pH, Sulfates, Chloride Ion, Electrical Resistivity)

The laboratory testing program often included examination of soil samples by an engineer. Based on the material’s texture and plasticity, we described and classified the soil samples in accordance with the Unified Soil Classification System.

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SITE LOCATION AND EXPLORATION PLANS

Contents:

Site Location Plan Exploration and Boring Plan

Note: All attachments are one page unless noted above.

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EXPLORATION RESULTS

Contents:

Boring Logs (B-1 through B-20) Concrete Core Photographs (10 pages) Summary of Testing Results Moisture Content Particle Size Analysis/Grain Size Distribution (4 pages) Atterberg Limits (4 pages) Modified Proctor (4 pages) Corrosivity (4 pages) CBR (17 pages) Infiltration Testing Results (3 pages)

Concrete Core Photographs Dobbins ARB Transient Apron Marietta, Georgia June 12, 2019 Terracon Project No. 49185336

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Photo 1 – B1 Core

Photo 2 – B2 Core

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Photo 3 – B3 Core

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Su m m ar y of

T es tin g

R es ul ts

Sa m pl e

ID

M oi st ur e

Cl as si fic at io n

At te rb er g Li m its

St an da rd

P ro ct or

Co rr os iv ity

CB

R At

.1 in

LL

PL

PI

M ax

D ry

De ns ity (p cf

O pt im um

M oi st ur e pH M in . S oi l

Re si tiv ity

(o hm

-c m

Ch lo rid e

M et ho d

B Su lfa te

(s ol ub le

Bl ow s

Pe r

La ye r pp m

(m g/ kg pp m (m g/ kg

.8 Sa nd y

Si lt

(M L)

3.

.8

6.

.0

0.

.8 Sa nd y

Si lt

(M

5.

.1

6.

.0

<1

.4 Sa nd y

Si lt

(M

4.

.9

6.

.0

.0

.8 Sa nd y

El as tic Si lt (M

H

4.

.5

5.

.0

<1

<0 .0

Client: Terracon Consultants, Inc.

Project: Transient Apron Reconstruction Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: --- Depth : ---

Sample Type: --- Test Date: 04/23/19 Test Id: 302537

Tested By: twh Checked By: jm

Moisture Content of Soil and Rock - ASTM D2216 printed 5/7/2019 9:11:09 AM

Boring ID Sample ID Depth Description Moisture Content,%

B- 1&B-12, B-3&B-7

B- 5&IT1,

B-13&B-9

B- 15&B-20, B-15&B-20

B- 16&B-11, B-8&B-5

0-10 ft

0-10 ft

0-10 ft

0-10 ft

Moist, reddish brown sandy silt

Moist, reddish brown sandy silt

Moist, reddish brown sandy silt

Moist, reddish brown sandy silt

28.8

23.8

14.4

22.8

Notes: Temperature of Drying : 110º Celsius

Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: B-1&B-12, B-3B-7 Depth : 0-10 ft

Sample Type: bag Test Date: 04/23/19 Test Id: 302535

Tested By: twh Checked By: jm

Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Particle Size Analysis - ASTM D6913 printed 5/7/2019 9:11:52 AM

1i n

3/ 4i n 1/

2i n

3/ 8i n

Sieve Name Sieve Size, mm Percent Finer Spec. Percent Complies

1in

3/4in

1/2in

3/8in

#4

#10

#20

#40

# 60

#100

#140

#200

25.00

19.00

12.50

9.50

4.75

2.00

0.85

0.42

0.25

0.15

0.11

0.075

Coefficients D =0.4550 mm85

D =0.0849 mm60

D =N/A50

D =N/A30

D =N/A15

D =N/A10

C =N/Au C =N/Ac

Classification ASTM Sandy SILT (ML)

AASHTO Clayey Soils (A-7-6 (10))

Sample/Test Description Sand/Gravel Particle Shape : ANGULAR

Sand/Gravel Hardness : HARD

Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: B-5&IT1, B-13B-9 Depth : 0-10 ft

Sample Type: bag Test Date: 04/23/19 Test Id: 302534

Tested By: twh Checked By: jm

Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Particle Size Analysis - ASTM D6913 printed 5/7/2019 9:11:53 AM

1i n

3/ 4i n 1/

2i n

3/ 8i n

Sieve Name Sieve Size, mm Percent Finer Spec. Percent Complies

1in

3/4in

1/2in

3/8in

#4

#10

#20

#40

# 60

#100

#140

#200

25.00

19.00

12.50

9.50

4.75

2.00

0.85

0.42

0.25

0.15

0.11

0.075

Coefficients D =0.5262 mm85

D =0.1153 mm60

D =N/A50

D =N/A30

D =N/A15

D =N/A10

C =N/Au C =N/Ac

Classification ASTM Sandy SILT (ML)

AASHTO Clayey Soils (A-7-5 (7))

Sample/Test Description Sand/Gravel Particle Shape : ---

Sand/Gravel Hardness : ---

Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: B-15&B-20, B-15B-20 Depth : 0-10 ft

Sample Type: bag Test Date: 04/23/19 Test Id: 302532

Tested By: twh Checked By: jm

Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Particle Size Analysis - ASTM D6913 printed 5/7/2019 9:11:55 AM

1i n

3/ 4i n 1/

2i n

3/ 8i n

Sieve Name Sieve Size, mm Percent Finer Spec. Percent Complies

1in

3/4in

1/2in

3/8in

#4

#10

#20

#40

# 60

#100

#140

#200

25.00

19.00

12.50

9.50

4.75

2.00

0.85

0.42

0.25

0.15

0.11

0.075

Coefficients D =0.5923 mm85

D =0.1207 mm60

D =N/A50

D =N/A30

D =N/A15

D =N/A10

C =N/Au C =N/Ac

Classification ASTM Sandy SILT (ML)

AASHTO Clayey Soils (A-7-6 (7))

Sample/Test Description Sand/Gravel Particle Shape : ANGULAR

Sand/Gravel Hardness : HARD

Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: B-16&B-11, B-8B-5 Depth : 0-10 ft

Sample Type: bag Test Date: 04/23/19 Test Id: 302533

Tested By: twh Checked By: jm

Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Particle Size Analysis - ASTM D6913 printed 5/7/2019 9:11:56 AM

1i n

3/ 4i n 1/

2i n

3/ 8i n

Sieve Name Sieve Size, mm Percent Finer Spec. Percent Complies

1in

3/4in

1/2in

3/8in

#4

#10

#20

#40

# 60

#100

#140

#200

25.00

19.00

12.50

9.50

4.75

2.00

0.85

0.42

0.25

0.15

0.11

0.075

Coefficients D =0.6135 mm85

D =0.1177 mm60

D =N/A50

D =N/A30

D =N/A15

D =N/A10

C =N/Au C =N/Ac

Classification ASTM Sandy Elastic SILT (MH)

AASHTO Clayey Soils (A-7-5 (7))

Sample/Test Description Sand/Gravel Particle Shape : ---

Sand/Gravel Hardness : ---

Project No: GTX-309826 Sample Type: bag Test Date: 04/25/19 Test Id: 302531

Tested By: twh Checked By: jm

Location: Dobbins Air Reserve Base Boring ID: --- Sample ID: B-1&B-12, B-3 B-7 Depth : 0-10 ft Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Atterberg Limits - ASTM D4318 printed 5/7/2019 9:04:31 AM

MH or OH

Symbol Sample ID Boring Depth Natural Moisture

Content,%

Liquid Limit

Plastic Limit

Plasticity Index

Liquidity Index

Soil Classification

B-1B-12, B-3B-7 --- 0-10 ft 29 49 29 20 0 Sandy SILT (ML)

Sample Prepared using the WET method

16% Retained on #40 Sieve

Dry Strength: HIGH

Dilatancy: NONE

Toughness: MEDIUM

Project No: GTX-309826 Sample Type: bag Test Date: 04/25/19 Test Id: 302530

Tested By: twh Checked By: jm

Location: Dobbins Air Reserve Base Boring ID: --- Sample ID: B-5&IT1, B-13 B-9 Depth : 0-10 ft Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Atterberg Limits - ASTM D4318 printed 5/7/2019 9:04:32 AM

MH or OH

Symbol Sample ID Boring Depth Natural Moisture

Content,%

Liquid Limit

Plastic Limit

Plasticity Index

Liquidity Index

Soil Classification

B-5IT1, B-13B-9 --- 0-10 ft 24 48 30 18 -0.3 Sandy SILT (ML)

Sample Prepared using the WET method

18% Retained on #40 Sieve

Dry Strength: MEDIUM

Project No: GTX-309826 Sample Type: bag Test Date: 04/25/19 Test Id: 302528

Tested By: twh Checked By: jm

Location: Dobbins Air Reserve Base Boring ID: --- Sample ID: B-15&B-20, B-15 B-20 Depth : 0-10 ft Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Atterberg Limits - ASTM D4318 printed 5/7/2019 9:04:33 AM

MH or OH

Symbol Sample ID Boring Depth Natural Moisture

Content,%

Liquid Limit

Plastic Limit

Plasticity Index

Liquidity Index

Soil Classification

B-15B-20, B-15B-20

--- 0-10 ft 14 46 29 17 -0.9 Sandy SILT (ML)

Sample Prepared using the WET method

19% Retained on #40 Sieve

Dry Strength: MEDIUM

Project No: GTX-309826 Sample Type: bag Test Date: 04/25/19 Test Id: 302529

Tested By: twh Checked By: jm

Location: Dobbins Air Reserve Base Boring ID: --- Sample ID: B-16&B-11, B-8 B-5 Depth : 0-10 ft Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Atterberg Limits - ASTM D4318 printed 5/7/2019 9:04:34 AM

MH or OH

Symbol Sample ID Boring Depth Natural Moisture

Content,%

Liquid Limit

Plastic Limit

Plasticity Index

Liquidity Index

Soil Classification

B-16B-11, B-8B-5 --- 0-10 ft 23 50 35 15 -0.8 Sandy Elastic SILT (MH)

Sample Prepared using the WET method

20% Retained on #40 Sieve

Dry Strength: MEDIUM

Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: B-1&B-12, B-3B-7 Depth : 0-10 ft

Sample Type: bag Test Date: 04/24/19 Test Id: 302543

Tested By: twh Checked By: jm

Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Compaction Report - ASTM D1557 printed 5/7/2019 9:12:32 AM

10 15 20 25 30

D ry

D en si ty pc f

Water Content, % zero air voids line

Data Points Point 1 Point 2 Point 3 Point 4

Dry density, pcf

Moisture Content, %

111.2

13.3

113.3

15.9

111.2

18.1

106.4

20.7

Method : A

Preparation : WET

As received Moisture :29 %

Rammer : Manual

Zero voids line based on assumed specific gravity of 2.65

Maximum Dry Density= 113.3 pcf Optimum Moisture= 15.8 %

Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: B-5&IT1, B-13B-9 Depth : 0-10 ft

Sample Type: bag Test Date: 04/30/19 Test Id: 302542

Tested By: twh Checked By: jm

Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Compaction Report - ASTM D1557 printed 5/7/2019 9:13:28 AM

5 10 15 20 25

D ry

D en si ty pc f

Water Content, % zero air voids line

Data Points Point 1 Point 2 Point 3 Point 4

Dry density, pcf

Moisture Content, %

111.8

11.7

114.8

13.5

113.1

16.4

109.9

18.7

Method : A

Preparation : WET

As received Moisture :24 %

Rammer : Manual

Zero voids line based on assumed specific gravity of 2.65

Maximum Dry Density= 115.0 pcf Optimum Moisture= 14.1 %

Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: B-15&B-20, B-15B-20 Depth : 0-10 ft

Sample Type: bag Test Date: 04/24/19 Test Id: 302540

Tested By: twh Checked By: jm

Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Compaction Report - ASTM D1557 printed 5/7/2019 9:14:00 AM

10 15 20 25 30

D ry

D en si ty pc f

Water Content, % zero air voids line

Data Points Point 1 Point 2 Point 3 Point 4

Dry density, pcf

Moisture Content, %

112.5

12.7

114.9

15.0

112.9

16.7

107.9

19.3

Method : A

Preparation : WET

As received Moisture :14 %

Rammer : Manual

Zero voids line based on assumed specific gravity of 2.65

Maximum Dry Density= 114.9 pcf Optimum Moisture= 14.9 %

Location: Dobbins Air Reserve Base Project No: GTX-309826 Boring ID: --- Sample ID: B-16&B-11, B-8B-5 Depth : 0-10 ft

Sample Type: bag Test Date: 04/23/19 Test Id: 302541

Tested By: twh Checked By: jm

Test Comment: --- Visual Description: Moist, reddish brown sandy silt Sample Comment: ---

Compaction Report - ASTM D1557 printed 5/7/2019 9:14:23 AM

5 10 15 20 25

D ry

D en si ty pc f

Water Content, % zero air voids line

Data Points Point 1 Point 2 Point 3 Point 4

Dry density, pcf

Moisture Content, %

113.5

12.4

114.6

14.6

112.4

17.0

106.9

19.6

Method : A

Preparation : WET

As received Moisture :23 %

Rammer : Manual

Zero voids line based on assumed specific gravity of 2.65

Maximum Dry Density= 114.6 pcf Optimum Moisture= 14.5 %

Project Name: Transient Apron Reconstruction Project Location: Dobbins Air Reserve Base

GTX #: 309826

Test Date: 04/23/19 Tested By: twh Checked By: jm

Boring ID Sample ID Depth, ft pH

--- B-1&B-12, B- 3&B-7 0-10 6.04

--- 'B-5&IT-1, B-

13&B-9 0-10 6.03

--- 'B-15&B-20, B- 15&B-20 0-10 6.75

--- 'B-16&B-11, B- 8&B-5 0-10 5.07

Notes:

pH by AASHTO T 289

Description

Moist, reddish brown sandy silt

Moist, reddish brown sandy silt

Moist, reddish brown sandy silt

Project Location: Dobbins Air Reserve Base

GTX #: 309826

Test Date: 04/24/19 Tested By: twh Checked By: jm

Boring ID Sample ID Depth, ft.

Minimum

Soil Resistivity, ohm-cm

--- B-1&B-12, B-3&B- 7 0-10 2,497

--- B-5&IT-1, B-

13&B-9 0-10 4,246

--- B-15&B-20, B- 15&B-20 0-10 3,144

--- B-16&B-11, B- 8&B-5 0-10 14,796

Comments: Test Equipment: Nilsson Model 400 Soil Resistance Meter, MC Miller Soil Box Test conducted in standard laboratory atmosphere: 68-73 F

Moist, reddish brown sandy silt

Sample Description

Moist, reddish brown sandy silt

Minimum Laboratory Soil Resistivity by AASHTO T 288

GEOTESTING EXPRESS INCORPORATED

2358 PERIMETER PARK DRIVE

SUITE 320

ATLANTA, GA 30341-1315

USA

Analysis No.

Report Date

Date Sampled

Date Received

Where Sampled

Sampled By

TS-A1907899

24 April 2019

22 April 2019

23 April 2019

Atlanta, GA USA

Client

This is to attest that we have examined: Soil for Project Name: Transit Apron Reconstruction; Site Location:

Dobbins Air Reserve Base; Job Number: GTX-309826

When examined to the applicable requirements of:

AASHTO T-291-13 “Standard Method of Test for Determining Water-Soluble Chloride Ion Content in Soil” Method B

AASHTO T-290-16 “Standard Method of Test for Determining Water-Soluble Sulfate Ion

Content in Soil”

Results:

AASHTO T-291 – Chloride Method B

Sample Results

Detection Limit ppm (mg/kg) %1

B1 + B-12, B-3 + B-7

44. 0.0044

10.

- 0 – 10’ B-15 + B-20, B-15 + B-20

38. 0.0038

- 0 – 10’

B-16 + B-11, B-8 + B-5

18. 0.0018

- 0 – 10’

B-5 + IT-1, B-13 + B-9

265. 0.0265

- 0 – 10’

NOTE: 1Percent by weight as received

PO Box 572455 / Salt Lake City UT 84157-2455 / USA TEL +1 801 262 2448 ∙ FAX +1 801 262 9870 ∙ www.TEi-TS.com

Analysis TS-A1907899 GeoTesting Express, Inc.

Report Date: 24 April 2019

CERTIFICATE OF ANALYSIS

© 2019 by Testing Engineers International, Inc. This certificate may not be reproduced except in full, without the expressed written consent of TEi- Testing Services, LLC. Note: The values in this certificate are the values obtained under standard test conditions as reported in the appropriate Report of Test and thus may be used for purposes of demonstrating compliance or for comparison with other units tested under the same standard.

The results do not indicate the function of the sample(s) under nonstandard or field conditions. This certificate gives the characteristics of the sample(s) submitted for testing only. It does not and may not be used to certify the characteristics of the product, nor to imply that the product in general meets the requirements of any standard, nor its acceptability in the marketplace. TEi-Testing Services is a wholly owned LLC of Testing Engineers International, Inc.

3455 South 500 West Salt Lake City, UT 84115-4234 USA

TEL: +1 801 262 2448

FAX: +1 801 262 9870

AASHTO T-290 - Sulfate (soluble)

Sample Results

Detection Limit ppm (mg/kg) %1

B1 + B-12, B-3 + B-7

14. 0.0014

10.

- 0 – 10’

B-15 + B-20, B-15 + B-20 <10. <0.0010

- 0 – 10’

B-16 + B-11, B-8 + B-5

12. 0.0012

- 0 – 10’

B-5 + IT-1, B-13 + B-9

<10. <0.0010

- 0 – 10’ NOTE: 1Percent by weight as received

END OF ANALYSIS

USEPA Laboratory ID UT00930

Project Location: Dobbins Air Reserve Base

GTX #: 309826 Tested By: ajn

Test Date: Checked By: jm

Boring ID: ---

Sample ID: B-1&B-12, B-3&B-7

Depth, ft. 0-10

Description: Moist, reddish brown sandy silt Preparation:

Comments: See attached CBR test reports for additional sample information Plotted CBR values are at 0.1 inch

93.7 99.7 107.6

California Bearing Ratio by ASTM D1883

Three test specimens compacted using 10, 25, and 56 blows per layer at the optimum moisture content (15.8%)

04/23/19

Blows per Layer Dry Density, pcf CBR at 0.1 in

Dry Density vs. Soaked CBR at 0.1 inches

85 90 95 100 105 110 115 120

S oa ke d

C B R

C or re ct ed

Dry Density, pcf

Project Location: Dobbins Air Reserve Base

GTX #: 309826 Tested By: trm

Test Date: Checked By: jm

Boring ID: ---

Sample ID: B-5&IT-1, B-13&B-9

Depth, ft. 0-10

Description: Moist, reddish brown sandy silt Preparation:

Comments: See attached CBR test reports for additional sample information Plotted CBR values are at 0.1 inch

93.0 105.3 113.5

California Bearing Ratio by ASTM D1883

Three test specimens compacted using 10, 25, and 56 blows per layer at the optimum moisture content (14.1%)

04/23/19

Blows per Layer Dry Density, pcf CBR at 0.1 in

Dry Density vs. Soaked CBR at 0.1 inches

85 90 95 100 105 110 115 120

S oa ke d

C B R

C or re ct ed

Proj…