Appendix_C_-_Limited_Preliminary_Geotechnical_Engineering_Exploration_Report.pdf

ITB PW 45-26

Project Opal

Bid Package #2 Phase 1 Improvements

APPENDIX C

UES

Limited/Preliminary Geotechnical

Engineering Exploration Report

September 8, 2025

Added via Addendum #4

LIMITED/PRELIMINARY GEOTECHNICAL ENGINEERING EXPLORATION REPORT

PROPOSED

SHOAL RIVER RANCH MANUFACTURING MULTI-PHASE DEVELOPMENT

MASON CEMETERY ROAD

CRESTVIEW, OKALOOSA COUNTY, FLORIDA

UES PROJECT NO. A25144.00837.000

UES REPORT NO. 2156668

SEPTEMBER 8, 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

September 8, 2025

AVCON, Inc.

320 Bayshore Drive, Ste. A Niceville, Florida 32578

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

TDNation@AVCONInc.com

RReference: Limited/Preliminary Geotechnical Engineering Exploration Report Proposed Shoal River Ranch Multi-Phase Development

Mason Cemetery Road Crestview, Okaloosa County, Florida

UES Project Number A25144.00837.000 UES Report Number 2156668

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 2156580 dated September 5, 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, lateral earth parameters, 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.

DN: c=US, o=UNIVERSAL

ENGINEERING SCIENCES

INC.,

dnQualifier=A01410D0000

018C15CC74F10007EFE5,

cn=Travis Monsalvatge Date: 2025.09.08 16:03:00 -05'00'

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 FOUNDATIONS

4.3.1 Building No. 1 Foundations

4.3.2 Building No. 2

4.3.3 Preliminary Considerations for Foundation Support of Building Nos. 3 & 4

4.3.4 Preliminary Considerations for Building No. 5

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 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 LATERAL EARTH PRESSURES AND RETAINING WALL FOUNDATION SOIL

4.9.1 General Wall Foundation Considerations

4.9.2 Wall Foundation Settlement Estimates

4.9.3 Wall Foundation Soil Evaluations

4.10 CONSTRUCTION RELATED SERVICES

4.11 EXCAVATION AND SAFETY

55.0 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

11.0 INTRODUCTION

In this report, UES has presented the results of the limited/preliminary geotechnical engineering exploration of the site for 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, LIMITED/PRELIMINARY RECOMMENDATIONS AND/OR EVALUATIONS – Presents limited/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, phone, and Microsoft Teams correspondences between April 1 and August 11, 2025. Included in these correspondences 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. As part of the project requirements, portions of the existing Jericho Road dirt road were also included in the geotechnical scope discussed in this report. At the time of UES’ field exploration, the project site was recently cleared timberland with several wood piles. One building structure was in the northern portion of the site.

Based on the provided information, UES understood that the proposed development would include the following:

Building No. 1: 250,000 sq. ft warehouse building which would entail a press pit and 20-ton capacity crane and have a finished site elevation of 213.25 feet-NAD83 (North American Datum 1983), and maximum structural loading conditions of 245 kips for columns and 7 kips per linear foot for load-bearing walls. The press pit would be installed near the center of the building footprint, and the exact dimensions were unknown. UES further understood that up to approximately 5 feet of excavation and 2 feet of fill would be required to achieve the planned finished site elevation for the building pad.

BBuilding No. 2: 250,000 sq. ft warehouse building which would have a finished site elevation of 213.25 feet-NAD83, and maximum structural loading conditions of 100 kips (structure loads of 75 kips plus additional weight for mechanical systems) for columns and 7 kips per linear foot for load-bearing walls. UES further understood that up to approximately 1 foot of excavation and 2 feet of fill would be required to achieve the planned finished site elevation for the building pad.

Building No. 3: 250,000 sq. ft warehouse building which would have a finished site elevation of 213.25 feet-NAD83, and maximum structural loading conditions of 100 kips (structure loads of 75 kips plus additional weight for mechanical systems) for columns and 7 kips per linear foot for load-bearing walls. UES further understood that up to approximately 4 feet of fill would be required to achieve the planned finished site elevation for the building pad.

Building No. 4: 250,000 sq. ft warehouse building which would have a finished site elevation of 213.25 feet-NAD83, and maximum structural loading conditions of 100 kips (structure loads of 75 kips plus additional weight for mechanical systems) for columns and 7 kips per linear foot for load-bearing walls. UES further understood that up to approximately 11 feet of fill would be required to achieve the planned finished site elevation for the building pad.

Building No. 5: A bunker-type building which would have a finished site elevation of 216 feet-NAD83. Based on the conceptual grading plan, Building No. 5 is depicted to occupy approximately 20,000 sq. ft. The construction type and size of the building had not been finalized by the Owner as of the date of this report. Structural loading information was also not known. UES understood that up to approximately 5 feet of excavation would be required to achieve the planned finished site elevation for the building pad. The earthen berm surrounding Building No. 5 has planned bottom elevations of 215 and 222 feet-NAD83 and a top of berm elevation of 228 feet-NAD83.

Western Pond: The planned bottom of pond elevation was established at 200 feet- NAD83 (North American Datum 1983). The Client anticipated that this would be a dry stormwater drainage/management pond. UES understood that up to approximately 20 feet of excavation would be required to achieve the planned bottom of pond elevation.

Northeastern and Southeastern Ponds: The planned bottom of pond elevation for each pond was established at 203 feet-NAD83 (North American Datum 1983). The Client anticipated that these ponds would be constructed as dry stormwater drainage/management ponds. UES understood that up to approximately 10 feet of excavation would be required to achieve the planned bottom of pond elevation for the northeastern pond and up to approximately 6 feet of excavation and 2 feet of fill would be required to achieve the planned bottom of pond elevation for the southeastern pond.

Other On-site/Off-site Improvements: Retaining walls would be required for the loading/unloading approaches for each of the warehouse buildings. It was understood that the retaining walls would have planned wall heights of approximately 3 feet or less above surrounding site grades. Up to approximately 8 feet of excavation and 7 feet of fill would be required to achieve finished site grades for the on-site pavement areas. Finished site grades for the planned Jericho Road pavement areas were anticipated to generally conform to existing site grades (i.e., within ±2 feet of current site grades).

UES understood that the project site would be developed in phases. Phase 1 of development would include mass-grading the entire site, construction of stormwater pond areas, perimeter pavements, pavements associated with Building No. 1, and the Building No. 1 structure. During this phase the building pads for Building Nos. 2, 3, and 4 would be prepared (i.e., made pad-ready). Subsequent construction phases would be completed in accordance with the Owner’s requirements at a later date.

Based on correspondence with the Client, the interior floor slabs for the proposed manufacturing buildings would be subjected to heavy loads including forklift traffic. UUES further understood that others will be responsible for the design of the interior floor slabs 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).

Per the Client’s request, the limited/preliminary scope of UES’ geotechnical services was to provide limited geotechnical recommendations and/or evaluations for the Building Nos. 1 and 2, lateral earth parameters for the retaining walls associated with the warehouse buildings, 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. For Building Nos. 3 and 4 only preliminary evaluations for general construction feasibility were included. For Building No. 5 and the associated earthen berm only the presentation of boring data obtained was included.

UES prepared other limited and supplemental geotechnical reports (UES Report Nos. 2149379 and 2152229 dated June 2 and June 23, 2025, respectively) to support the ongoing changes in design. The pertinent and relevant information obtained and published in these previous reports have been reproduced and/or updated in this report to reflect the project understanding on the date of this limited/preliminary report. Some of the previous borings which are no longer relevant to the design have been omitted from this report and its appendices.

Portions of this evaluation and/or limited/preliminary geotechnical report are preliminary in nature. Additional geotechnical engineering exploration would be necessary, particularly for Building Nos. 3 and 4 following completion of site grading operations for the building pads and pending final designs of the buildings. Additional geotechnical exploration may also be required in other areas of the site (e.g., Building No. 5) once structural and grading plans have been finalized.

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, pavement, retaining wall, 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, lateral earth parameters, 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.

22.3 GEOTECHNICAL EXPLORATION

The field exploration program was initiated on April 14, 2025 and completed on August 2, 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 plan titled Concept Option #2 and the conceptual grading plan (DWG file), 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 methods of measurement and/or location 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 would recommend 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 dated of applicable limited and/or supplemental reports.

The samples would then be discarded unless UES has been notified and other arrangements have been made.

22.4 FIELD EXPLORATION

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

Performing 41 Standard Penetration Test (SPT) borings within/near the proposed building areas. Four 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 37 SPT borings within the on-site and off-site pavement areas. These borings were drilled to approximate depths of 6 or 15 feet BEG.

Performing 21 SPT borings (SW-3, SW-11 through SW-30) within/near the proposed stormwater drainage/management areas. These borings were drilled to approximate depths of 20, 25, 30, or 40 feet BEG.

Performing 3 SPT borings within the retaining wall areas. These borings were drilled to an approximate depth 35 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.

22.5.2 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

(fft)

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.

33.2 SURFACE CONDITIONS

UES personnel visited the project site during the performance of the field explorations. At the times of the field exploration program, the site was being cleared or was cleared of the planted trees. One building with associated concrete sidewalks was located within the northern portion of the site. The portion of Jericho Road which was included with the project was a dirt road.

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-NAD83. 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 interfaces 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 boring locations on the dates drilled.

Table 2 – General Soil Profile (Building, Pavement, Retaining Wall, and Berm 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 or clay

[SP-SM, SP-SC], and silty and/or clayey SAND [SM, SC- SM, SC]; Very stiff to hard CLAY [CL, CL/CH]

2 to 41

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, B-9, B-33, and B-36).

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

Groundwater was encountered in the building borings at approximate depths of 18 ½ to 27 ½ feet BEG (approximate elevations of 182 ½ to 197 feet-NAD83) either during drilling or immediately upon completion of the borings. Groundwater was not encountered in the pavement borings.

TTable 33 –– GGeneral Soil Profile ((Western Pond Borings) SSW--33, SW--111 through SW--113, and SW--222 through SW--2288

SStratum NNo.

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 silty clayey SAND [SM, SC-SM]

3 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 (SW-3, SW-11 through SW-15, and SW-22 through SW-25).

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

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

Table 44 –– GGeneral Soil Profile ((Northeastern and Southeastern Pond Borings) SW--14 through SW--211, SW--29, and SW--30

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).

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

At the time of the field exploration, groundwater was encountered at approximate depths of 17 to 21 feet BEG (approximate elevations of 181 to 193 ½ feet-NAD83) in the borings associated with the proposed northeastern and southeastern ponds. Groundwater was not encountered during drilling for Boring SW-30.

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.

TTable 55 SSummary of CCBBR (AASTM D1883)) and Moisture--DDensity Relations of Soils (AASTM D1557)) Test Results

SSample Number/ LLocation//Ground SSurface Elevation

SSample DDepths

BBEG

((iinches))

MMaterial Description/EEstimated

USCS Soil Classification

Dry Density of Test

Specimen (llbs./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

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.

TTable 66 CCBR and Modulus of Subgrade Reaction Estimates Based on Field DCP Test Data

BBoring 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 66 NNotes:

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 (approximate elevations of 181 to 197 ½ feet-NAD83). The pavement borings were terminated at approximate depths of 6 and 15 feet BEG and pond boring SW-30 was terminated at an approximate depth of 20 feet BEG.

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, except for Boring SW-30, to be at approximate depths of 15 to 24 ½ feet BEG (approximate elevations of 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.

44.3 BUILDING FOUNDATIONS

4.3.1 Building No. 1 Foundations

Based on the results of our geotechnical exploration, UES would consider the subsurface conditions at the site to be unacceptable for support of the proposed Building No. 1 structure on conventional shallow foundations. UES understood that the proposed building would have maximum structural loading conditions of 245 kips for columns and 7 kips per linear foot for load-bearing walls. UES further understood that up to approximately 5 feet of excavation and 2 feet of fill would be necessary to achieve the desired finished grade elevation of 213.25 feet-

NAD83.

Based on the boring data obtained, the provided structural loading conditions, and anticipated site grading, there would be significant risks and problems with total and differential settlements of the proposed Building No. 1 structure if supported on conventional shallow foundations. To alleviate the potential significant settlement risks and problems, ground improvement or modification would be recommended for support of the proposed structure. The presence of silty and/or clayey soils [SM, SC, SC-SM, CL, CL/CH] would generally prohibit the use of vibro-replacement with sand. For this project, UES would recommend the use of vibro-compaction (VC) “stone columns” for support of the proposed building.

The use of VC “stone columns” would necessitate the services of a specialty contractor experienced with this type of ground improvement. Using the data obtained from this exploration, the specialty contractor would perform the geotechnical engineering services that would be required to determine the design (i.e., number, pattern, and depth of columns, etc.) and construction/installation requirements for the stone columns. UES would be pleased to provide the Client with the names of specialty contractors who would be capable of providing and performing such services.

Regarding design requirements and performance criteria, UES would recommend that total settlement not exceed 1 inch, differential settlement not exceed ½ inch, and the design allowable bearing capacity be predicated on a minimum factor of safety of 2 with load testing. The improved bearing capacity must not be less than 3,000 pounds per square foot (psf).

Although other ground improvement and deep foundation techniques have been discussed with the Design team, UES understood that the Client’s preference and basis for the Structural Engineer’s foundation design was for vibro-compaction. If the Client wishes UES to consider other techniques and offer recommendations (if applicable), then UES would be pleased to provide such services for an additional fee.

44.3.2 Building No. 2

Based on the results of our geotechnical exploration, and anticipated construction challenges associated with undercutting and recompacting the subgrade soils, UES would consider the subsurface conditions at the site to be impractical for support of the proposed Building No. 2 structure on conventional shallow foundations. UES understood/assumed that the proposed building would have the maximum structural loading conditions of 100 kips (structure loads of 75 kips plus additional weight for mechanical systems) for columns and 7 kips per linear foot for load-bearing walls. UES further understood that up to approximately 1 foot of excavation and 2 feet of fill would be necessary to achieve the desired finished grade elevation of 213.25 feet-NAD83.

Based on the boring data obtained, the provided structural loading conditions, and anticipated site grading, there would be significant risks and problems with total and differential settlements of the proposed Building No. 2 structure if supported on conventional shallow foundations.

Due to the proximity of Building No.2 to Building No. 1, undercutting and recompacting the subgrade soils to improve the allowable bearing capacity would be challenging and may not be feasible. UES understood that Building No. 1 would be constructed before construction of Building No. 2 would commence. Therefore, UES has recommended that VC “stone columns” also be used for Building No. 2. The construction/installation of stone columns for Building No.

2 should be performed in conjunction with the ground improvement program for Building No. 1 (i.e., prior to starting vertical construction for Building No. 1).

The design and performance criteria for Building No. 1 would also apply for the VC program associated with Building No. 2.

44.3.3 Preliminary Considerations for Foundation Support of Building Nos. 3 & 4

UES understood that the building pads for Building Nos. 3 and 4 would be constructed as part of Phase 1 of the development. Based on the provided conceptual grading plan, UES further understood that up to approximately 4 feet of fill would be required to achieve finished grade for Building No. 3 pad and up to 11 feet of fill would be required to achieve finished grade for Building No. 4 pad. Structural loading conditions for each building were not anticipated to exceed 100 kips for columns and 7 kips per linear foot for load-bearing walls.

There would be two settlement loads associated with each building. One load would be the settlement associated with the proposed buildings, and the second load would be associated with the weight of the fill on the project site. UES understood that vertical construction of Building Nos. 3 and 4 would be delayed an undetermined number of years. Therefore, UES has recommended that a professional surveyor be retained to determine the as-constructed ground surface elevations of each pad immediately following completion of grading operations and immediately prior to construction of each building so that necessary adjustments could be made to achieve planned finished site grades. UES has also recommended that additional geotechnical engineering evaluation and/or exploration be performed to provide final geotechnical design recommendations for the building foundations following completion of site grading operations for the building areas.

4.3.4 Preliminary Considerations for Building No. 5

Sufficient information regarding Building No. 5 (i.e., construction type, finalized dimensions, structural loading conditions, etc.) was not available at the time of UES’ geotechnical exploration and this report. Based on the conceptual grading plan, up to approximately 6 feet of excavation would be required to achieve the finished site elevation of 216 feet-NAD83.

Due to the lack of pertinent information for the performance of a geotechnical evaluation, UES’ services were limited to the performance of borings within the planned building area. The subsurface conditions were generally similar to those encountered elsewhere on the site. For additional information, refer to the Boring Logs attached in Appendix B.

Following completion of necessary design development, UES would be pleased to perform a supplemental evaluation for foundation support of Building No. 5 for an additional fee.

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.

Based on CBR testing performed for this exploration and estimated correlations with soil classifications and CBR values 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 vvalue of 9 percent for a sand with silt [SP-SM] with 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.

44.5.2 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 10,000 square feet of placed pavement, or a minimum of three cores per day’s production, whichever is greater.

44.5.4 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.