Appendix_A_-_UES_Limited_Geotechnical_Engineering_Exploration_Report.pdf

ITB PW 45-26

Project Opal

Bid Package #2 Phase 1 Improvements

APPENDIX A

UES Limited Geotechnical Engineering

Exploration Report

June 2, 2025

LIMITED GEOTECHNICAL ENGINEERING EXPLORATION REPORT

PROPOSED SHOAL RIVER RANCH MANUFACTURING FACILITY – PHASE 1

MASON CEMETERY ROAD

CRESTVIEW, OKALOOSA COUNTY, FLORIDA

UES PROJECT NO. 1730.2500009.0000

UES REPORT NO. 2149379

JUNE 2, 2025

Prepared For:

AVCON, Inc.

320 Bayshore Drive, Ste. A

Niceville, Florida 32578

Prepared By:

UES Professional Solutions, LLC 1985 Cope Lane

Pensacola, Florida 32526

June 2, 2025

AVCON, Inc.

320 Bayshore Drive, Ste. A Niceville, Florida 32578

Attention: Ms. Tonia D. Nation, P.E.

TDNation@AVCONInc.com

Reference: Limited Geotechnical Engineering Exploration Report Proposed Shoal River Ranch Manufacturing Facility – Phase 1 Mason Cemetery Road

Crestview, Okaloosa County, Florida UES Project Number 1730.2500009.0000

UES Report Number 2149379

Ms. Nation:

UES Professional Solutions, LLC (UES) has completed a limited/preliminary geotechnical engineering exploration of the above referenced site in Crestview, Okaloosa County, Florida. These services were performed in general accordance with the authorized UES Proposal Number 2140521 dated April 3, 2025 and subsequent emails with the Client on April 15 and 17, 2025.

The following report has presented the results of the completed limited/preliminary geotechnical engineering exploration, and a geotechnical engineering interpretation of the exploration results with respect to the project characteristics provided to UES. UES’ limited/preliminary geotechnical engineering recommendations and/or evaluations for foundation design, pavement considerations, stormwater management, site preparation, and construction related services have been included in the report.

UES has appreciated the opportunity to have worked with the Client on this project and looks forward to a continued association. Please contact UES if there are any questions concerning this report or if UES may be of further assistance as the project plans proceed.

Respectfully Submitted, UES PROFESSIONAL SOLUTIONS, LLC

Certificate of Authorization Number 549

Travis W. Monsalvatge, P.E. Michael A. Johnson, P.E.

Pensacola Branch Manager Senior Geotechnical Engineer Florida P.E. Number 82244 Florida P.E. Number 35974

This item has been electronically signed and sealed by Travis W. Monsalvatge, P.E. using a digital signature. Printed Copies of this document are not considered signed and sealed, and the signature must be verified on any electronic copies.

mailto:TDNation@AVCONInc.com

TABLE OF CONTENTS

1.0 INTRODUCTION

2.0 SCOPE OF SERVICES

2.1 PROJECT DESCRIPTION

2.2 PURPOSES

2.3 GEOTECHNICAL EXPLORATION

2.4 FIELD EXPLORATION

2.5 LABORATORY TESTING

2.5.1 Visual Classification

2.5.2 Laboratory Soils Testing

3.0 FINDINGS

3.1 USDA NRCS SOIL SURVEY

3.2 SURFACE CONDITIONS

3.3 SUBSURFACE CONDITIONS

3.4 CALIFORNIA BEARING RATIO (CBR) AND MODIFIED PROCTOR TEST RESULTS

3.5 ESTIMATED CBR AND MODULUS OF SUBGRADE REACTION VALUES BASED ON

DCP TESTING

4.0 LIMITED/PRELIMINARY RECOMMENDATIONS AND/OR EVALUATIONS

4.1 GEOTECHNICAL ASSESSMENT

4.2 GROUNDWATER CONSIDERATIONS

4.3 BUILDING NO. 1 FOUNDATIONS

4.3.1 General

4.3.2 Allowable Net Soil Bearing Pressure

4.3.3 Foundation Size

4.3.4 Bearing Depths

4.3.5 Bearing Materials

4.3.6 Settlement Estimates

4.3.7 Foundation Evaluations

4.4 FLOOR SLABS

4.5 PRELIMINARY EVALUATIONS FOR FLEXIBLE (ASPHALT) PAVEMENTS

4.5.1 Stabilized Subgrade

4.5.2 Base Course

4.5.3 Hot Mix Asphalt (HMA) Surface Course

4.5.4 Effects of Groundwater

4.5.5 Curbing

4.5.6 Construction Traffic

4.6 PRELIMINARY EVALUATIONS FOR RIGID (CONCRETE) PAVEMENTS

4.6.1 Subgrade Preparation

4.6.2 Concrete Placement

4.6.3 Effects of Groundwater

4.7 PRELIMINARY STORMWATER MANAGEMENT CONSIDERATIONS

4.7.1 Western Pond

4.7.2 Northeastern Pond

4.7.3 Southeastern Pond

4.8 SITE PREPARATION

4.8.1 Temporary Groundwater Control

4.8.2 Nearby Structures and Vibrations

4.8.3 Existing Underground Utilities

4.8.4 Site Preparation and Grading

4.8.5 Fill Placement

4.8.6 Earth Fill Materials

4.8.7 Compaction Recommendations

4.8.8 Test Criteria to Evaluate Fill and Compaction

4.9 CONSTRUCTION RELATED SERVICES

4.10 EXCAVATION AND SAFETY

5.0 LIMITATIONS

LIST OF APPENDICES

SITE VICINITY MAP .................................................................................................................................................. A USDA NRCS SOIL SURVEY MAP ......................................................................................................................... A

BORING LOCATION PLAN .................................................................................................................................... B BORING LOGS ......................................................................................................................................................... B BORING PROFILES .................................................................................................................................................. B KEY TO BORING LOGS ......................................................................................................................................... B REPORTS OF DCP TEST RESULTS (PCASE 7.03) ........................................................................................... B FIELD PROCEDURES .............................................................................................................................................. B

REPORTS OF CBR (ASTM D1883) AND PROCTOR (ASTM D1557) TEST RESULTS ................................ C LABORATORY TESTING PROCEDURES ........................................................................................................... C

GEOTECHNICAL BUSINESS COUNCIL (GBC) DOCUMENT ....................................................................... D CONSTRAINTS AND RESTRICTIONS ................................................................................................................. D GENERAL CONDITIONS ........................................................................................................................................ D

1.0 INTRODUCTION

In this report, UES has presented the results of the limited/preliminary geotechnical engineering exploration of the site for Phase 1 of the proposed Shoal River Ranch manufacturing facility project. This report has been divided into the following sections:

• SCOPE OF SERVICES – Discusses what we did,

• FINDINGS – Discusses what we encountered,

• PRELIMINARY EVALUATIONS/RECOMMENDATIONS – Presents preliminary geotechnical engineering related information regarding the proposed development

• LIMITATIONS – Discusses the restrictions inherent in this report,

• APPENDICES – Presents support materials referenced in this report.

2.0 SCOPE OF SERVICES

2.1 PROJECT DESCRIPTION

Project information was provided to UES by the Client via email and phone correspondence between April 1 and May 12, 2025. Included in this correspondence were several documents for our use in the performance of this geotechnical exploration and the preparation of this report.

• Concept Option #3 (undated) prepared by the Client and provided on April 1, 2025

• Concept Option #2 (undated) prepared by the Client and provided on April 15, 2025

• Okaloosa County Project Opal at Shoal River Ranch Topographic Survey prepared by

Gustin, Cothern & Tucker, Inc. and dated April 11, 2025

• Conceptual Grading Plan (undated DWG file) prepared by the Client and provided on

May 12, 2025

The project site was located west of Mason Cemetery Road (also known as Jericho Road) in Crestview, Okaloosa County, Florida. The site entailed a 112-acre portion of one parcel totaling approximately 331 acres identified by the Okaloosa County Property Appraiser as Parcel ID 20-3N-22-0000-0001-0040. At the time of UES’ field exploration, the project site was moderately to heavily wooded timber land with one building located within the northern portion of the site.

UES’ geotechnical services proposal was prepared on the basis of Concept Option #3 which depicted three stormwater management ponds (hereafter referenced as the western, northeastern, and southeastern ponds), a bunker type building structure in the southwest end of the site, four 250,000 square foot (sq. ft) single-story manufacturing building structures near the middle of the site, and perimeter access drives and parking areas.

Following the performance of soil borings SW-1, SW-2, SW-4, and SW-5, UES was informed that the owner would move forward with Concept Option #2 instead. The western pond depicted in Concept Option #2 was significantly smaller and the western border of the pond was moved further east. As such, these borings would no longer be applicable to the project.

UES has included the Boring Logs for SW-1, SW-2, SW-4, and SW-5 in Appendix B for reference only. Additional borings (SW-22, SW-23, SW-24, and SW-25) were authorized by the Client and some of the remaining borings planned for the western pond were relocated to accommodate the Concept Option #2 configuration.

On May 12, 2025, UES was provided with a conceptual grading plan which presented additional differences from the previously referenced Concept Option #3 and Concept Option #2 plans. Some of the differences have been summarized below:

• The western pond was shifted slightly east of the previously depicted locations. The planned southern boundary of the western pond was located further north than previously understood and the planned bottom of pond elevation was established at 200 feet-NAD83 (North American Datum 1983). Based on these changes, Borings SW- 1, SW-2, and SW-4 through SW-10 would no longer be applicable to the western pond.

• The northeastern pond was generally similar to what was depicted on Concept Option #2. The planned bottom of pond elevation was established at 203 feet-NAD83.

• The southeastern pond southern boundary extended slightly further south than previously understood. The planned bottom of pond elevation was established at 203 feet-NAD83.

• The alignment of the four 250,000 sq. ft buildings was shifted slightly east and the planned finished floor elevation was established at 213 feet-NAD83. Approach drives for truck loading/unloading to the west of each of these buildings would incorporate a retaining wall along the north side of each access drive.

• The bunker type building structure, associated parking and drive areas, and earthen berm were relocated to the northern end of the proposed development. This building structure has a planned footprint of approximately 20,000 sq. ft and finished floor elevation of 216 feet-NAD83. The earthen berm has planned bottom elevations of 215 and 220 feet-NAD83 and a top of berm elevation of 228 feet-NAD83.

Per the Client’s request, the authorized UES’ geotechnical proposal dated April 3, 2025, and additional work authorized via email on April 15 and 17, 2025, this geotechnical exploration addressed the proposed northernmost manufacturing building (Building No. 1), stormwater ponds, the parking lot immediately east of Building No. 1, and associated perimeter access drives as depicted on Concept Option #3 and Concept Option #3 plans. In addition, the Client requested UES to advance one boring, designated X-1, within the subject parcel and south of the proposed development. Other proposed developments indicated on Concept Option #2 and the conceptual grading plan such as future building areas and/or earthen berms/dams were beyond the requested geotechnical scope.

Based on correspondence with the Client, the interior floor slab for the proposed manufacturing buildings would be subjected to heavy loads including forklift traffic. UES understood that a pit would be constructed within Building No. 1. UES further understood that others will be responsible for the design of the interior floor slab and pavements for the project site. UES was requested to provide estimated CBR and modulus of subgrade reaction values for evaluated surficial soils for the Civil and/or Structural Engineer’s use in their design(s).

The limited/preliminary scope of UES’ geotechnical services was to provide limited/preliminary geotechnical recommendations and/or evaluations for the northernmost manufacturing building (Building No. 1), stormwater management areas of the site, site preparation, and construction related services, as well as present/provide CBR values based on testing and CBR and modulus of subgrade reaction values estimated using dynamic cone penetrometer (DCP) test results.

Structural loading information was not provided to UES. Based on experience with similar construction, UES assumed for the purposes of this exploration that the proposed Building No.

1 structure would be supported on conventional shallow foundations with a maximum structural loading condition of 6 kips per linear foot for load-bearing walls and 200 kips for columns.

UES understood, based on the provided conceptual grading plan, the maximum proposed depths of excavation or fill required to achieve finished site grades were as follows:

• Up to 5 feet of excavation and 2 feet of fill for the proposed Building No. 1 area

• Up to 10 feet of excavation for the proposed northeastern pond

• Up to 6 feet of excavation and 2 feet of fill for the proposed southeastern pond

• Up to 20 feet of excavation for the proposed western pond

• Up to 8 feet of excavation and 7 feet of fill for the proposed pavement areas.

This limited/preliminary geotechnical report is preliminary in nature. Additional geotechnical explorations should be performed to sufficiently address the changes to project information discussed in this report.

No other site or project facilities should be designed using the soil information contained herein. As such, UES would not be responsible for the performance of any other site improvements designed using the data in this report.

2.2 PURPOSES

The purposes of this limited/preliminary exploration program were:

• To explore the general site and subsurface conditions in the proposed Building No. 1, perimeter access drive and parking area associated with Building No. 1, and stormwater management areas of the site;

• To interpret and review the site and subsurface conditions with respect to the proposed development;

• To perform a series of laboratory tests on selected subsurface soil samples to assist with engineering soil classification and to establish relevant soil engineering characteristics; and

• To provide limited/preliminary geotechnical engineering recommendations and/or evaluations for foundation and pavement design, site preparation, and construction related services.

• To provide limited geotechnical engineering evaluations of the sites of the proposed stormwater management areas.

This report has presented an evaluation of site conditions based on traditional geotechnical engineering procedures for site characterization. The recovered samples were not examined, either visually or analytically, for chemical composition or environmental hazards. UES would be pleased to provide the Client with a proposal for these services, if desired.

The exploration was confined to the zone of soil likely to be stressed by the proposed construction. The exploration has not addressed the potential for surface expression of deep geological conditions. Such an evaluation would require a more extensive scope of field services than was performed for this exploration. UES would be pleased to provide a proposal for an exploration to evaluate the probable effect of the regional geology upon the proposed construction, if desired.

2.3 GEOTECHNICAL EXPLORATION

The field exploration program was initiated on April 13, 2025 and completed on May 6, 2025.

The approximate boring locations have been shown on the attached Boring Location Plan in Appendix B. The approximate boring locations were determined in the field using the provided conceptual site plans (Concept Option #3 and Concept Option #2), a hand-held GPS, Google Earth aerial imagery and GPS information, and existing field reference points on and adjacent to the site. The boring locations should be considered accurate only to the degree implied by the method of measurement used.

UES was provided with topographic information for the project site. As such, the elevations at the boring locations have been estimated to the nearest whole foot and presented on the Boring Logs in Appendix B and/or discussed in this report. If the existing ground surface elevations should be considered critical for design, we have recommended that a professional surveyor be retained by the Client.

During the performance of the field testing and sampling, recovered soil samples were placed in labeled plastic containers, sealed, and transported to the laboratory where the samples were examined by members of the UES geotechnical engineering staff. Various samples of the soils were then selected for specific laboratory testing. The recovered soil samples not used for laboratory testing would be held in the UES laboratory for the Client’s inspection for a time period of 90 days following the issue date of this report. The samples would then be discarded unless UES has been notified and other arrangements have been made.

2.4 FIELD EXPLORATION

Based on our experience and understanding of the previously discussed project information, our field exploration consisted of the following:

• Performing 9 Standard Penetration Test (SPT) borings within/near the proposed Building No. 1 area. Two borings were drilled to approximately 100 feet below existing grade (BEG) and the remainder of the borings were drilled to approximately 50 feet

BEG.

• Performing 9 SPT borings (SW-1, SW-2, and SW-4 through SW-10) within the area previously understood to be within the western pond area. These borings were drilled to approximate depths of 30 or 40 feet BEG. As previously noted, these borings would no longer be applicable to the western pond area.

• Performing 8 SPT borings (SW-3, SW-11 through SW-13, and SW-22 through SW-25) within/near the proposed western pond area. Each boring was drilled to approximate depths of 30 or 40 feet BEG.

• Performing 4 SPT borings (SW-14 through SW-17) within the northeastern pond area.

Each boring was drilled to approximate depths of 30 or 40 feet BEG.

• Performing 4 SPT borings (SW-18 through SW-21) within the southeastern pond area.

Each boring was drilled to approximate depths of 30 or 25 feet BEG.

• Performing 13 SPT borings, each boring drilled to approximate depths of 6 or 15 feet BEG, within/near the proposed pavement areas.

• Performing 1 SPT boring (X-1) , as requested by the Client, drilled to an approximate depth of 50 feet BEG.

• Performing Dynamic Cone Penetrometer (DCP) testing at 4 locations to depths of approximately 3 feet BEG.

• Collecting 4 samples for California Bearing Ratio (CBR)(ASTM D1883) and modified Proctor (ASTM D1557) testing.

Descriptions of the field procedures performed have been presented in the Field Procedures attachment in Appendix B.

2.5 LABORATORY TESTING

2.5.1 Visual Classification

In the laboratory, the soil samples recovered from the field exploration were visually and physically examined by members of the UES geotechnical engineering staff. Approximate soil classifications were estimated in general accordance with the Unified Soil Classification System (ASTM D2487). The resulting soil descriptions and estimated soil classifications have been presented on the Boring Logs in Appendix B. Where applicable, the descriptions and classifications presented on the Boring Logs have been revised to reflect the results of any laboratory testing performed on the samples.

2.5.2 Laboratory Soils Testing

Laboratory testing was performed on selected representative soil samples to aid in the USCS classification of the soils and to help in the evaluation of pertinent geotechnical engineering characteristics/properties of the soils. The laboratory testing completed for this project consisted of performing the following procedures/tests in general accordance with the methods listed.

• Natural Moisture Content Tests – ASTM D2216

• Percent -200 Soil Fines Content Tests – ASTM D1140

• Atterberg Limits Tests – ASTM D4318

• California Bearing Ratio Tests – ASTM D1883

• Modified Proctor Tests – ASTM D1557

• Remolded Falling-Head Permeability Tests – FM 5-513

Detailed descriptions of these test procedures have been presented in the Laboratory Testing Procedures attachment in Appendix C. The results of the tests have been summarized on the Boring Logs attached in Appendix B, presented on individual reports in Appendix C, and/or discussed subsequently in this report.

3.0 FINDINGS

3.1 USDA NRCS SOIL SURVEY

Based on the published and Web Soil Surveys for Okaloosa County, Florida, as prepared by the United States Department of Agriculture Natural Resources Conservation Service (USDA NRCS), the predominant, pre-development soil type at the site has been identified as: 12 – Lakeland sand, 0 to 5 percent slopes. A summary of the characteristics of the soil type within the area to be developed was obtained from the Soil Surveys and has been included in Table

1. Please note the soil type presented in the following table would be the pre-development soil type and may have been altered during past development of the site.

Table 1 – Summary of USDA NRCS Soil Survey Information

Soil Type Constituents (Depth-in.)

Internal Drainage

Hydrologic Soil Group

Soil Permeability Seasonal High

Water Table

(ft)

Corrosion Potential

Depth

(in)

Perm

(in/hr)

Uncoated

Steel Concrete

12 – Lakeland sand, 0 to 5% slopes

SP-SM

(0-49)

SP, SP-SM

(49-80)

Excessively drained

A 0-49

49-80

6.0-20

6.0-20 >6.7 Low Moderate

Based on the boring data obtained, the shallow subsurface soil and groundwater conditions encountered were generally similar to those presented in Table 1.

3.2 SURFACE CONDITIONS

UES personnel visited the project site during the performance of the field exploration. At the time of the field exploration program, the site was moderately to heavily wooded timber land.

One building with associated concrete sidewalks was located within the northern portion of the site.

As discussed previously, UES was provided with topographic information for the project site.

Based on available elevation information, elevations on the site ranged from approximately 197 to 225 feet. Based on observation, the site appeared to be relatively level to gently sloping.

3.3 SUBSURFACE CONDITIONS

The general subsurface conditions encountered during the field exploration have been described in Tables 2, 3, and 4. For more detailed soil descriptions and stratifications at the boring locations, the Boring Logs attached in Appendix B should be reviewed. Also, see the Key to Boring Logs in Appendix B for further explanation of the symbols and placement of data on the Boring Logs.

The Boring Logs represent UES’ interpretation of the subsurface conditions based on a review of the field logs, an engineering examination of the recovered soil samples, and a limited number of laboratory tests. The horizontal stratification lines designating the interface between various strata represented approximate boundaries. Transition between different strata in the field may be gradual in both the horizontal and vertical directions. Groundwater, or lack thereof, encountered in the borings, and noted on the Boring Logs, represented conditions only at the time of the exploration.

Table 2 – General Soil Profile (Building No. 1 and Pavement Borings)

Stratum No.

Typical depth (ft) Soil Descriptions

Range of SPT “N” Blow Counts From To

1 0 0.1 Sandy TOPSOIL1 ---

2 0.1 100 2 Very loose to dense SAND [SP], SAND with silt [SP-SM], silty SAND [SM], and occasionally clayey SAND [SC] 2 to 33

1 Topsoil is a term used to describe organic soils, which are usually dark in color, and typically suitable for the support of plant life.

2 Termination depth of the deepest borings (B-1 and B-9).

[ ] Brackets indicate Unified Soil Classification System (ASTM D2487)

Groundwater was encountered in the building borings at approximate depths of 21 to 22 ½ feet BEG (190 to 195 ½ feet-NAD83) either during drilling or immediately upon completion of the borings. Groundwater was not encountered in the pavement borings.

Table 3 – General Soil Profile (Western Pond Borings) SW-3, SW-11 through SW-13, and SW-22 through SW-25

Stratum No.

Typical depth (ft) Soil Descriptions Range of SPT “N”

Blow Counts From To

1 0 0.1 Sandy TOPSOIL1 ---

2 0.1 40 2 Very loose to medium dense SAND [SP], SAND with silt [SP-SM], and silty and/or clayey SAND [SM, SC-SM]

3 to 29

1 Topsoil is a term used to describe organic soils, which are usually dark in color, and typically suitable for the support of plant life.

2 Termination depth of the borings.

Groundwater was encountered in the western pond borings at approximate depths of 19 ½ to 26 ½ feet BEG (187 to 197 ½ feet-NAD83) either during drilling or immediately following completion of the borings.

Table 4 – General Soil Profile (Northeastern and Southeastern Pond Borings) SW-14 through SW-17 and SW-18 through SW-21

Stratum No.

Typical depth (ft) Soil Descriptions

Range of SPT “N” Blow Counts From To

1 0 0.1 to 0.2 Sandy TOPSOIL1 ---

2 0.1 to 0.2 402 Very loose to dense SAND [SP], SAND with silt [SP-SM], and occasionally silty SAND [SM]

2 to 32

1 Topsoil is a term used to describe organic soils, which are usually dark in color, and typically suitable for the support of plant life.

2 Termination depth of the deepest borings (SW-14 and SW-15).

At the time of the field exploration, groundwater was encountered at approximate depths of 17 to 21 feet BEG (181 to 193 ½ feet-NAD83) in the borings associated with the proposed northeastern and southeastern ponds.

3.4 CALIFORNIA BEARING RATIO (CBR) AND MODIFIED PROCTOR TEST RESULTS

Four California Bearing Ratio (CBR) tests and four moisture-density relations of soils (also known as modified Proctor compaction tests) were performed for bulk samples of soils.

Information regarding the specific locations and sample depths have been presented in Table

5. The CBR testing was performed in general accordance with ASTM D1883. The moisture-density relations of soils testing was performed in general accordance with ASTM D1557. A summary of the test results has been presented in Table 5, and the test reports have been presented in Appendix C.

Table 5 Summary of CBR (ASTM D1883) and Moisture-Density Relations of Soils (ASTM D1557) Test Results

Sample Number/ Location/Ground Surface Elevation

Sample Depths

BEG

(inches)

Material Description/Estimated

USCS Soil Classification

Dry Density of Test

Specimen (lbs./ft.3)

Compaction Moisture Content (% by dry soil wt.)

Corrected CBR at 0.1 in

Percent Compaction

CBR -1 / West Pond (±210 ft-

NAD83)

6 to 12 Tan Brown SAND with silt [SP-SM] 106.1 10.8 9.3 96

6 to 12 Tan Brown SAND with silt [SP-SM] 107.6 11.1 14 97

6 to 12 Tan Brown SAND with silt [SP-SM] 110.3 10.9 15 99

Table 5 Summary of CBR (ASTM D1883) and Moisture-Density Relations of Soils (ASTM D1557) Test Results

Sample Number/ Location/Ground Surface Elevation

Sample Depths

BEG

(inches)

Material Description/Estimated

USCS Soil Classification

Dry Density of Test

Specimen (lbs./ft.3)

Compaction Moisture Content (% by dry soil wt.)

Corrected CBR at 0.1 in

Percent Compaction

CBR-2/ Building No. 1

(±217.5 ft-NAD83)

6 to 12 Tan Brown SAND with silt [SP-SM]

105.2 10.9 15 95

6 to 12 Tan Brown SAND with silt [SP-SM]

107.2 10.9 22 97

6 to 12 Tan Brown SAND with silt [SP-SM]

109.5 10.8 26 99

CBR-3/

Northeast Pond (±211 ft-NAD83)

6 to 12 Tan Brown SAND with silt [SP-SM]

104.8 11.3 12 96

6 to 12 Tan Brown SAND with silt [SP-SM]

106.1 11.4 18 97

6 to 12 Tan Brown SAND with silt [SP-SM] 108.3 11.4 36 99

CBR-4/

Southeast Pond

(±206.5 ft-

NAD83)

6 to 12 Tan Brown SAND with silt [SP-SM] 104.9 11.1 12 95

6 to 12 Tan Brown SAND with silt [SP-SM] 106.3 11.4 18 97

6 to 12 Tan Brown SAND with silt [SP-SM] 108.5 11.4 36 99

Table 5 Notes:

CBR-1: Maximum Dry Density (MDD) of 110.9 pounds per cubic foot (pcf) at an optimum moisture of 11.0 percent for a sand with 7.2 percent passing the number 200 sieve (fines) by soil dry weight CBR-2: MDD of 110.5 pcf at an optimum moisture of 10.7 percent for a sand with 7.1 percent fines CBR-3: MDD of 109.2 pcf at an optimum moisture of 11.5 percent for a sand with 6.8 percent fines CBR-4: MDD of 109.9 pcf at an optimum moisture of 11.4 percent for a sand with 5.9 percent fines

* Compaction percentage based on MDD and optimum moisture values for each CBR sample.

**Estimated ground surface elevations based on provided conceptual grading plan

3.5 ESTIMATED CBR AND MODULUS OF SUBGRADE REACTION VALUES BASED ON DCP

TESTING

Dynamic cone penetrometer (DCP) testing was performed at four locations extending from at or near the ground surface down to an approximate depth of 36 inches BEG. The testing was performed in general accordance with ASTM D6951 and procedures established in the U.S.

Army Engineer Research and Development Center (ERDC) publication, “Evaluation of In Situ Pavement Layers with Dynamic Cone Penetrometer (DCP)” dated April 9, 2007.

The field DCP data was correlated with CBR values based on established relationships noted in the aforementioned documents. Graphical representations of the field data as they relate to estimated CBR values have been presented in Appendix B of this report. In addition, UES utilized the Pavement Computer Aided Structural Engineering (PCASE) software program to further evaluate the field data and determine the estimated modulus of subgrade reaction values for the subgrade soils evaluated.

The CBR values and layer thicknesses for the first layer estimated using the field DCP data at each test location have been summarized in Table 6. The modulus of subgrade reaction values determined using the PCASE software program have also been presented in Table 6.

Table 6 CBR and Modulus of Subgrade Reaction Estimates Based on Field DCP Test Data

Boring Number/Location

Estimated Ground Surface Elevation (ft-

NAD83)

Estimated First Layer Thickness

(in.)

Estimated First Layer CBR (%)

Estimated First Layer Modulus of Subgrade

Reaction (pounds per cubic inch)

DCP-1 215 6 1.8 74

DCP-2 216.5 8 2.6 92

DCP-3 208 6 3.7 113

DCP-4 202 6 2.8 96

Table 6 Notes:

Estimated ground surface elevations based on provided conceptual grading plan.

PCase DCP-CBR data correlation reports have been presented in Appendix B

4.0 LIMITED/PRELIMINARY RECOMMENDATIONS AND/OR EVALUATIONS

4.1 GEOTECHNICAL ASSESSMENT

In this section of the report, UES has presented limited/preliminary recommendations and/or evaluations for foundation design of Building No. 1, pavement design, site preparation, stormwater management, and construction related services. The following recommendations and/or evaluations were developed on the basis of the previously described project characteristics and the site and subsurface conditions encountered by the field exploration.

If there should be any changes in these project criteria, including building and pond locations on the site, such information should promptly be reported to UES such that adjustments to planned future geotechnical explorations can be accomplished prior to completion of proposed work.

Once final design plans have become available, a general review by UES will be required to determine what additional information and services will be required to provide final geotechnical engineering design recommendations for the provided final plans.

4.2 GROUNDWATER CONSIDERATIONS

The groundwater level would fluctuate seasonally depending upon local rainfall. The typical wet season groundwater level has been defined as the highest groundwater level sustained for a period of 2 to 4 weeks during the "wet" season of the year, for existing site conditions, in a year with average normal rainfall amounts. Based on historical data and the Web Soil Survey, the rainy season in Northwest Florida would typically be between June and September and may include the winter months of any given year.

At the time of the field exploration, phreatic groundwater levels were encountered in most of the borings at approximate depths of 17 to 26 ½ feet BEG (181 to 197 ½ feet-NAD83). The pavement borings were terminated at approximate depths of 6 to 15 feet BEG and groundwater was not encountered in these borings during drilling operations. UES has estimated the normal stabilized seasonal high phreatic groundwater levels at the building and pond boring locations to be at approximate depths of 15 to 24 ½ feet BEG (183 to 199 ½ feet-NAD83). The presented estimates for seasonal high phreatic groundwater levels have been based upon Okaloosa County Soil Survey information, data obtained from the UES exploration, regional hydrogeology, local climate/rainfall data, experience, and a review of USGS data.

It should be noted that the estimated seasonal high phreatic groundwater levels would not provide any assurance that groundwater levels would not be higher/shallower than the estimated levels in the future. Should impediments to surface water drainage be present, or should rainfall intensity, duration, and/or quantities, exceed the normally anticipated rainfall conditions, then groundwater levels could be higher/shallower than our seasonal high estimates. Furthermore, it should be understood that changes in the surface hydrology and subsurface drainage from on-site, and/or off-site improvements could have significant effects on the normal and seasonal high groundwater levels.

UES has recommended that positive drainage be established and maintained on the site during construction. UES has further recommended that permanent measures be constructed to maintain positive drainage throughout the life of the project. All site improvement designs should incorporate the seasonal high groundwater levels as appropriate.

4.3 BUILDING NO. 1 FOUNDATIONS

4.3.1 General

Based on the results of our geotechnical exploration, we have considered the subsurface conditions at the site to be adaptable for support of the proposed structure when constructed on properly designed conventional shallow foundation systems. Provided the site preparation and earthwork construction recommendations outlined in Section 4.8 of this report have been performed, the following parameters may be used for the foundation design.

As noted previously, the building foundation recommendations provided in this report have been based on our understanding that 5 feet or less of excavation and 2 feet or less of fill would be necessary to achieve the desired finished grade elevation in the proposed Building No. 1 area, single-story manufacturing building type of construction, and assumed maximum structural loading conditions of 200 kips for columns and 6 kips per linear foot for load-bearing walls.

When the actual structural loads and final grading information have been determined, UES should be notified and new settlement estimates should be performed (if they exceed the structural loading estimates previously discussed above) or the recommendations presented herein are not considered valid.

4.3.2 Allowable Net Soil Bearing Pressure

The maximum allowable net soil bearing pressure for use in the shallow foundation design should not exceed 1,250 psf for the foundations for code dead and live loads plus any short duration loadings. This bearing pressure has been predicated on the bearing subgrade soils to a depth of 1 foot below the foundation bearing elevation(s) having been densified to at least 95 percent of the modified Proctor maximum dry density (ASTM D1557) prior to foundation construction.

Net bearing pressure has been defined as the soil bearing pressure at the base of the foundation in excess of the natural overburden pressure. The foundations should be designed based upon the maximum loads that could be imposed by all loading conditions.

Ground improvement techniques such as vibro-replacement and deep dynamic compaction may also be a consideration. A specialized geotechnical Contractor would provide design recommendations for the selected method and be responsible for both design and performance. Typically, the use of these methods would result in improved bearing capacities on the order of 3,000 to 5,000 psf depending on the technique and improvement method.

For vibro-replacement, either sand or aggregate may be utilized. However, it may be more advantageous to use sand instead of aggregate due to the planned pit in Building No. 1. This method uses vibration to displace and densify subsurface materials and then backfill the space created with a suitable material.

Deep dynamic compaction (DDC) would densify subsurface materials to certain depths depending on the type and size of pounder, height of drop, grid pattern, and number of passes. As a result of DDC, craters would be created near the ground surface which would have to be backfilled. Typically, 4 to 5 feet of fill would be required at the ground surface following performance of DDC but this amount may vary depending on the geotechnical Contractor’s design parameters.

4.3.3 Foundation Size

The minimum widths recommended for any isolated column foundations and continuous wall foundations would be 24 inches and 18 inches, respectively. Even though the maximum allowable net soil bearing pressure may not be achieved, these width recommendations would control the minimum size of the foundations to prevent “shear punch” deformations.

4.3.4 Bearing Depths

The exterior foundations should bear at a depth of at least 24 inches below the finished exterior grades, and the interior foundations should bear at a depth of at least 18 inches below the finish floor elevation, to provide confinement to the bearing level soils. Stormwater should be diverted from the building exteriors to reduce the possibility of erosion beneath the exterior foundations.

4.3.5 Bearing Materials

The foundations may bear in either compacted suitable new structural fill or on-site soils. The foundation excavation bottoms should be level or suitably benched and free of any loose soils that have been disturbed by seepage or the construction process. Furthermore, the foundation excavation bottoms should be free of ponded water. The bearing level soils, after compaction, should exhibit densities of at least 95 percent of the modified Proctor maximum dry density (ASTM D1557) to a depth of at least 1 foot below the foundation bearing level.

4.3.6 Settlement Estimates

Post-construction settlement of the proposed Building No. 1 structure will be influenced by several interrelated factors, such as: subsurface stratification and strength/compressibility characteristics; foundation sizes, bearing levels, applied loads, and resulting pressures beneath the foundations; and site preparation and earthwork construction techniques used by the Contractor. Our settlement estimates for the proposed structure have been based on the assumed structural loading information, and compliance with the site preparation/earthwork recommendations in Section 4.8 of this report. Any deviation from these recommendations could result in an increase in the estimated post-construction settlement of the structures.

Based on the subsurface/subsoil conditions encountered by the exploration and the recommended earthwork operations, UES would expect the majority of settlement to occur fairly rapidly during construction. Using the recommended maximum net allowable bearing pressure, the assumed maximum structural loading conditions, and the field data which has been correlated with geotechnical engineering strength and compressibility characteristics of the subsurface soils, UES has estimated that total settlement of the proposed structure would be approximately 1 inch or less.

Differential settlements result from differences in applied bearing pressures and variations in the compressibility characteristics of the subsurface soils. Because of the general uniformity of the subsurface conditions and the recommended site preparation and earthwork construction techniques outlined in Section 4.8, we have estimated that differential settlement of the proposed structure should be within tolerable magnitudes on the order of about ½ inch or less over a 40 feet long portion of continuous/strip foundation or between similarly spaced isolated foundations.

Based on experience, the estimated differential settlement would typically be considered structurally tolerable; however, aesthetic cracking in masonry and brick walls could occur. If such cracking was to be undesirable, then the Structural Engineer would need to design the wall/foundation system with sufficient stiffness to minimize such cracking.

4.3.7 Foundation Evaluations

Foundation excavations should be evaluated by the Geotechnical Engineer of Record, or his Representative, to determine that soils present at and immediately below the bearing level would be capable of supporting the recommended design bearing pressure. We have recommended that the bearing soils at the bottom of and below the foundation excavations be checked using a hand held steel probe rod and/or a dynamic cone penetrometer to assess the suitability of the soils. Foundation evaluations should be performed prior to steel reinforcement and concrete placement.

It should be anticipated that undercutting of select areas may be required because of variations in the soil matrix, fill quality, and/or Contractor means and methods. If unsuitable bearing soils should be encountered, these soils would need to be removed. The foundations could then be established at the new lower bearing elevation or back filled with lean concrete or flowable fill pending compaction of the upper 1 foot of soils at the newer bearing elevation.

If compacted structural fill should be used as backfill, then the undercut excavations to remove unsuitable materials should be centered beneath the foundations, and widened 1 foot for each foot of undercut depth. If No. 57 crushed stone, lean concrete or flowable fill should be used as backfill, then the foundation excavations need not be widened. If more than 6 inches of crushed stone were to be installed, then the crushed stone should be wrapped with a geotextile fabric to reduce the potential for soil migration into the stone.

4.4 FLOOR SLABS

UES understood that the floor slabs would be subjected to forklift traffic. Per correspondence with the Client, the design of the floor slabs would be performed by others, including recommendations for subgrade preparation. The slabs should be structurally isolated from other foundation elements or adequately reinforced to prevent distress due to differential movements.

According to established interrelationships published by the Portland Cement Association (PCA) in 1966, a modulus of subgrade reaction (k) value of 190 pounds per cubic inch would correlate with CBR value of 9 percent and a minimum compaction requirement of 96 percent of the modified Proctor (ASTM D1557) maximum dry density. Refer to Table 5 of this report for additional information regarding CBR test values and related degrees of compaction. The presented subgrade modulus obtained from the referenced publication has not incorporated a factor of safety. The Designer should apply a factor of safety as appropriate.

UES has recommended the use of a vapor barrier which covers the bearing soils beneath ground supported floor slabs in accordance with Florida Building Code (FBC) requirements.

The FBC recommends a minimum 6-mil thick polyvinyl chloride or polyethylene sheet membrane for this purpose. The performance of the vapor barrier would ultimately be dependent upon its proper installation, including lapping and sealing plus repair of tears and punctures prior to placement of concrete.

4.5 PRELIMINARY EVALUATIONS FOR FLEXIBLE (ASPHALT) PAVEMENTS

As previously discussed, UES understood that the design of the proposed flexible pavement sections would be the responsibility of others. Based on the DCP tests performed across the site, the near-surface soils had in-situ CBR values of approximately 1.8 to 3.7 percent (Section 3.5). Four bulk samples were obtained for CBR (ASTM D1883) and modified Proctor (ASTM D1557) testing. When prepared and compacted in accordance with the recommendations of this report, the tested materials should be capable of achieving CBR values of up to approximately 36 percent or Limerock Bearing Ratio (LBR) values of up to approximately 45 percent. However, as evident from the CBR testing performed, at least some of the on-site soils would not be capable of achieving a minimum LBR value of 40 percent.

In the following subsections, UES has presented general/typical recommendations regarding the various pavement section layers in accordance with latest version of the Florida Department of Transportation (FDOT) “Standard Specifications for Road and Bridge Construction” (SSRBC).

4.5.1 Stabilized Subgrade

The stabilized subgrade would be the top surface of a roadbed upon which the pavement structure and shoulders have been constructed. The primary function of the stabilized subgrade would be to provide a stable and firm platform for construction of the pavement without undue deflection that would impact the pavement’s performance. In addition, the stabilized subgrade would enhance the overall strength of the pavement section.

Beneath all base course materials, UES would typically recommend a stabilized subgrade having a minimum Limerock Bearing Ratio (LBR) (FM 5-515) of 40 percent, and a minimum compacted thickness of 12 inches as specified by the latest version of the FDOT SSRBC for Type B Stabilized Subgrade, Section 160 and Section 914. The stabilized subgrade material would be compacted to at least 98 percent of the modified Proctor maximum dry density (ASTM D1557) value at a moisture content within ±2 percent of the modified Proctor optimum moisture content.

For soils not meeting the LBR requirement, a stabilized subgrade could be constructed by blending the soils with a stabilizing agent such as limerock or soil fines. If a blend was to be proposed, UES would recommend that the Contractor perform a mix design to determine the optimum mix proportions. The need for a stabilizing agent to be mixed with either on-site existing fill soils or proposed imported fill soils to meet the required LBR of 40 percent for the stabilized subgrade would need to be verified by the Contractor before bidding and construction.

4.5.2 Base Course

The base course would be a layer or layers of select or specified material(s) of designed thickness(es) which have been placed on a subbase or stabilized subgrade to provide uniform and stable support for binder and surface courses. The base course would typically provide a significant portion of the structural capacity in a flexible pavement system.

Two of the most commonly used base materials in Northwest Florida are limerock and graded aggregate base (GAB). For this project, UES would typically recommend that the limerock base course consist of locally available limerock complying with the requirements of the FDOT SSRBC, Section 200 and Section 911. Alternatively, UES would recommend that the use of GAB be in accordance with Section 204 of the latest edition of the FDOT SSRBC. A minimum LBR of 100 would be used for limerock base and GAB courses, and the base material would need to be obtained from an FDOT approved source. Regardless of the material selected, the base course would need to be compacted to 98 percent of the modified Proctor (ASTM D1557) maximum dry density at a moisture content within +2 percent of the modified Proctor optimum moisture content.

4.5.3 Hot Mix Asphalt (HMA) Surface Course

The surface course would consist of FDOT SuperPave (SP fine) asphaltic concrete having a minimum field density of 93.5% of the laboratory maximum density (Gmm). Specific requirements for the SuperPave asphaltic concrete structural course have been outlined in the current edition of the FDOT SSRBC, Section 334.

The allowable layer thicknesses for Type SP Asphalt Concrete mixtures would 1 to 1-½ inches for Type SP-9.5, and 1-½ to 3 inches for Type SP-12.5. Type SP-9.5 has been limited to the top two (2) structural layers and has been limited to a maximum of two (2) layers.

Hot mix asphalt (HMA) mixes would need to be FDOT approved, assigned an FDOT Mix Design Number, and current. HMA mixes would have a “fine” gradation classification. UES would recommend the percent of Reclaimed Asphalt Pavement (RAP) be limited to less than 30 percent. The Asphalt Binder Grade for HMA with less than 20 percent RAP is PG 67-22. The Asphalt Binder Grade for HMA with 20 to 29 percent RAP is PG 64-22.

After placement and field compaction, the asphaltic concrete would need to be cored to evaluate material thickness and to perform laboratory densities. Cores would need to be obtained at frequencies of at least one core per 5,000 square feet of placed pavement, or a minimum of three cores per day’s production, whichever is greater.

4.5.4 Effects of Groundwater

One of the most critical factors influencing pavement performance in Northwest Florida has been the relationship between the pavement subgrade and the groundwater level.

Roadways and parking areas have been damaged as a result of deterioration of the base conditions and/or the base/surface course bond. UES would typically recommend that the seasonal high groundwater table and the bottom of the flexible pavement base course be separated by at least 24 inches.

4.5.5 Curbing

Typical curbing would be extruded and placed atop the pavement surface. This type of curbing would not act as a horizontal cutoff for lateral migration of storm and irrigation water into the base material. Because of this, it has been common for base and subgrade materials adjacent to these areas to become saturated, promoting subsequent localized pavement deterioration.