Report of Geotechnical Engineering Investigation OIA SOUTH CELL LOT (W340) AID Project No. GOA16001 Orange County, Florida GEC Project No.

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1 Report of Geotechnical Engineering Investigation OIA SOUTH CELL LOT (W40) AID Project No. GOA16001 Orange County, Florida GEC Project No. 956G

2 July 6, 2017 American Infrastructure Development, Inc. 7 North Orange Avenue Suite 500 Orlando, Florida 2801 Attention: Subject: Mr. Mark Jansen, P.E., LEED BD+C Report of Geotechnical Engineering Investigation OIA SOUTH CELL LOT (W40) AID Project No. GOA16001 Orange County, Florida GEC Project No. 956G Dear Mr. Jansen: Geotechnical and Environmental Consultants, Inc. (GEC) is pleased to present this Report of Geotechnical Engineering Investigation for the above-referenced project. This study was performed in general accordance with our Proposal No. 858G dated March 15, The purpose of this study was to explore soil and groundwater conditions at the subject site and to use the information obtained to develop geotechnical engineering recommendations regarding site preparation and design of the structure foundations and pavement areas. This report describes our exploration procedures, exhibits the data obtained and presents our conclusions and recommendations regarding the geotechnical engineering aspects of the project. GEC appreciates the opportunity to be of service to you on this project and trusts that the information contained herein is sufficient for your current needs. Should you have any questions concerning the contents of this report, or if we may be of further assistance, please contact us.

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4 TABLE OF CONTENTS 1.0 SITE AND PROJECT DESCRIPTION NRCS SOIL SURVEY USGS POTENTIOMETRIC MAP DATA SUBSURFACE EXPLORATION Standard Penetration Test Borings Hand Auger Borings Manual Muck Probes Groundwater Measurement LABORATORY TESTING DESCRIPTION OF SUBSURFACE CONDITIONS Boring Results Groundwater Levels ANALYSIS AND DESIGN RECOMMENDATIONS Foundations Pavements Unpaved Access Road for Pond SAR-D Stormwater Pond Weir Structure Lateral Earth Pressures Uplift Resistance CONSTRUCTION ISSUES General Site Preparation Fill Selection, Placement and Compaction Foundation Subgrade Preparation Pavement Subgrade Preparation Temporary Dewatering Temporary Excavations USE OF THIS REPORT GEC Project No. 956G iii Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

5 APPENDIX Figure 1: Figure 2: Figures - 4: Figure 5: USGS Quadrangle and NRCS Soil Survey Maps Boring Location Plan Boring Results Muck Probe Location Plan and Results TABLES Table 7: Table 8: Summary of Laboratory Test Results Summary of Corrosion Series Test Results GEC Project No. 956G iv Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

6 1.0 SITE AND PROJECT DESCRIPTION The project site is located in south Orange County in Orlando, Florida. More specifically the site is located near the northeast corner of the intersection of Jeff Fuqua Boulevard and South Park Place approximately 2,500 feet south of the OIA Mid-Cross Field Taxiway. The project site is approximately 6-acres in area and is currently mostly undeveloped with dense tree coverage. The site is bordered to the east by the existing Red Lot, to the west by the new South Terminal currently under construction and to the south by an existing stormwater pond. The approximate site vicinity is shown on an excerpt of the United States Geological Survey (USGS) Pine Castle, Florida Quadrangle map on Figure 1 in the Appendix. Based on our review of the USGS Quadrangle map, the ground surface elevation across the site ranges from approximately +81 to +90 feet NGVD. the project will consist of a new cell phone parking lot new paved access roads reconstruction of the existing toll booths a new weir structure and shell access road GEC understands that the project will consist of the construction of a new cell phone parking lot with space for approximately 200 vehicles. In association with the new parking lot, approximately 1,200 feet of new paved access roads are planned. Also planned is the reconstruction of the existing toll booths for the adjacent Red Lot. The new toll booths will be reconstructed approximately 500 feet east of their current locations. In addition, a new weir structure and shell access road to the weir is planned at the southern end of the existing stormwater pond (SAR-D) south of South Park Place. The weir structure will be an approximately 48-foot long concrete structure bearing on stabilized subgrade soils in the southern portion of the existing pond. The structure will include skimmer poles anchored into the existing pond bottom. 2.0 NRCS SOIL SURVEY The Natural Resources Conservation Service (NRCS) Soil Survey of Orange County, Florida was reviewed to obtain surficial soil and groundwater information in the vicinity of the subject site. An excerpt of the NRCS Soil Survey map showing the approximate site area is presented on Figure 1 in the Appendix. The NRCS soils near the project site are summarized in the following Table 1: GEC Project No. 956G 1 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

7 Table 1 Orange County NRCS Soil Units Summary Soil Unit Soil Name Basinger fine sand, depressional, 0 to 1 percent slopes 26 Ona fine sand 4 44 Pomello fine sand, 0 to 5 percent slopes Smyrna fine sand, 0 to 2 percent slopes Depth (in) Soil Description Unified Soil Classification Depth to Seasonal High Groundwater (ft) Hydrologic Group 0-80 Fine sand SP-SM A/D Fine sand Fine sand, sand Fine sand, sand Fine sand Fine sand Fine sand Loamy fine sand, fine sand Fine sand SP, SP-SM SM, SP-SM SP, SP-SM SP-SM SP SP, SP-SM SP-SM, SM SP, SP-SM B/D A A/D The soils depicted on the NRCS Soil Survey across the majority of project site are Ona fine sand (Soil Unit 26) and Smyrna fine sand, 0 to 2 percent slopes (Soil Unit 44). In general the soil types across the project site are classified as fine sand with varying silt content (SP, SP-SM, SM) and are generally suitable for construction. The NRCS predicts seasonal high groundwater levels to range from 2 feet above the ground surface to.5 feet below the natural ground surface within the project vicinity. Information contained in the NRCS Soil Survey is very general and may be outdated. It may not, therefore, be reflective of actual soil and groundwater conditions, particularly if recent development in the site vicinity has modified soil conditions or surface/subsurface drainage. The information obtained from the soil borings provides a better characterization of actual site conditions..0 USGS POTENTIOMETRIC MAP DATA Based on our review of the USGS map entitled The Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, September, 2008 the potentiometric level of the Floridan aquifer in the vicinity of the subject site is approximately +49 feet NGVD. Since the existing ground surface elevations in the vicinity of the subject site ranges from approximately +81 to +90 feet NGVD, artesian flow conditions are not anticipated at this site. Artesian conditions were not encountered in our soil borings. GEC Project No. 956G 2 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

8 4.0 SUBSURFACE EXPLORATION In addition to consulting the sources of information previously discussed for regional and sitespecific soils data, GEC conducted a subsurface exploration to evaluate soil and groundwater conditions. GEC explored subsurface conditions at the subject site by performing borings at the locations listed in the following Table 2. Table 2 Summary of Field Investigation Program Project Element *Boring Type Boring No. Depth (ft) Figure No. Paved Parking/Drive Areas AB HA-1 to HA to 5.5 Toll Booth Structures SPT TB-1 and TB Weir Structure SPT B-1 and B * AB Auger boring, SPT Standard Penetration Test boring. In addition to the borings listed above, manual muck probes were performed along the proposed weir structure on an approximate 5-foot by 10-foot grid. Also, as requested two manual muck probes were performed within the existing triangular stormwater pond to help evaluate any organic removal needed for the stormwater pond expansion and backfilling. The approximate locations of the borings performed for this study are shown on Figure 2 in the Appendix. These locations were not surveyed, but rather by using a handheld, sub-meter accuracy global positioning satellite (GPS) unit (Trimble Geo XH Series). Although these locations are given only approximately, the methods used to locate them are, in GEC s opinion, sufficient to meet the intent of our study. If greater accuracy is desired, a registered Professional Land Surveyor should be retained to survey these locations. 4.1 Standard Penetration Test Borings SPT borings were drilled in general accordance with ASTM Procedure D The boreholes were advanced by the rotary wash method with bentonite-based mud used as the circulating fluid to stabilize the borehole. GEC s field crew obtained SPT samples continuously in the borings to a depth of 10 feet and at 5-foot depth intervals thereafter. A GEC engineering technician monitored the drilling operation, and collected, examined and visually classified each sample. He then packaged representative portions of each sample for transport to our laboratory for further examination and laboratory testing. GEC Project No. 956G Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

9 4.2 Hand Auger Borings Our engineering technician performed standard barrel hand auger borings, ASTM D-4700, by manually turning a -inch diameter, 6-inch long sampler into the soil until it was full. He then retrieved the sampler and visually examined and classified the soil. This procedure was repeated until the desired termination depth was achieved. Our technician collected representative samples for further visual examination and classification in our laboratory. 4. Manual Muck Probes Manual muck probes were performed by pushing a slender metal rod into the surficial soil and evaluating the relative resistance of the soil to manual penetration. Highly organic soils, such as muck and/or peat, are characteristically very soft and will easily yield to the manual probe. Manual probes, however, cannot detect peat or muck layers which are present beneath layers of sand or dense soils which cannot be penetrated by the probe. The probes can also penetrate to some extent in very loose sands which may be present beneath peat or muck layers. No soil samples are obtained for visual examination or laboratory testing when using this exploratory technique. The soil type being penetrated is inferred solely by evaluating the relative resistance of The probe data presented in this report should be evaluated with these limitations in mind. 4.4 Groundwater Measurement the soil to penetration. These limitations can lead to some under-estimation or over-estimation of peat or muck layer thicknesses. The probe data presented in this report should be evaluated with these limitations in mind. A GEC engineering technician measured the depth to groundwater in the boreholes at the time of drilling and again after approximately 24 hours. Once the 24-hour groundwater measurement was recorded, the boreholes were then backfilled with soil cuttings to prevailing ground surface. 5.0 LABORATORY TESTING Selected soil samples retrieved from the borings were tested in accordance with Florida Standard Testing Methods (FM). Florida Standard Testing Methods are adaptations of recognized standard methods, e.g., ASTM and AASHTO, which have been modified to accommodate Florida s geological conditions. The GEC laboratory is reviewed annually by the Construction Materials Engineering Council, Inc. (CMEC) to verify compliance with FM. Our laboratory testing program is summarized on the following table: GEC Project No. 956G 4 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

10 Table Summary of Laboratory Testing Program Number of Type of Test Tests Grain Size Analysis (FM 1-T 088) 5 Percent Fines (FM 1-T88) 8 Natural Moisture Content (FM 1-T 265) 1 Atterberg Limits (FM 1-T 89/90) 1 Corrosion Series (FM 5-550/551/552/55) 2 The results of our laboratory tests for the SPT borings are shown adjacent to the soil profiles on the SPT Boring Results sheet. The results of our laboratory testing for the auger borings are summarized on the Summary of Laboratory Test Results Table (Table 7) in the Appendix. Corrosion series tests were performed on representative soil and water samples obtained at the proposed weir structure to evaluate the substructure environmental classification. In accordance with the FDOT Structure Design Guidelines and the results of our corrosion series test results, the detailed corrosion test results are presented in Table 8 in the Appendix. 6.0 DESCRIPTION OF SUBSURFACE CONDITIONS Detailed records of subsurface conditions encountered in our auger and SPT borings are shown on Figures and 4 in the Appendix. The boring logs describe the soil layers using the Unified Soil Classification System (USCS) symbol (e.g., SP-SM) and ASTM soil descriptions (e.g., sand with silt). We based our soil classifications and descriptions on visual examination and the limited laboratory soil classification testing shown on the Boring Results sheets in the Appendix. The boring logs indicate subsurface conditions only at the specific boring locations at the time of our field exploration. Subsurface conditions, including groundwater levels, at other locations of the subject site may differ from conditions we encountered at the boring locations. Moreover, conditions at the boring locations can change over time. Groundwater levels fluctuate seasonally, and soil conditions can be altered by earthmoving operations. The depths and thicknesses of the subsurface strata indicated on the boring logs were interpolated between samples obtained at different depths in the borings. The actual transition between soil layers may be different than indicated. These stratification lines were used for our analytical GEC Project No. 956G 5 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

11 purposes. Earthwork quantity estimates based on the results of the borings will vary from the actual quantities measured during construction. 6.1 Boring Results In general, the SPT borings performed for the toll booth and weir structures typically encountered the following generalized subsurface profile. Table 4 Generalized Subsurface Profile for SPT Borings Soil Borings TB-1, TB-2, B-1 and B-2 Approximate Layer Depth (feet) Typical Soil Description Typical Range of N-Values (blows/foot) 0 to 27 Loose to medium dense fine sand with silt to silty fine sand (SP-SM, SM) with occasional trace organic material and roots 8 to to 0 Stiff to very stiff sandy lean clay (CL) 8 to 16 Notable exceptions to the generalized subsurface profile detailed in Table 4 include the following: Borings TB-1 and TB-2 were terminated at a depth of 15 feet below the existing ground surface. Boring TB-1 encountered dense to very dense (N-value of 29 to 54) fine sand with silt to silty fine sand (SP-SM, SM) from the ground surface to 1 feet below the existing ground surface. The auger borings performed within the paved parking/drive areas (HA-1 to HA-10) typically encountered sands with varying silt content (SP, SP-SM, SM) with occasional trace organic material and roots to the boring termination depths of 1.5 to 5.5 feet below the existing ground surface. The manual probes performed for the weir structure and stormwater pond expansion/backfilling encountered 0 to 5.5 feet of standing water underlain by 0.2 One of the manual probes to 1-foot of loose sands/soft sediments. One of the manual encountered 0.5 feet of surficial probes encountered 0.5 feet of surficial deleterious material deleterious material (muck) (muck); however the remainder of the probes did not GEC Project No. 956G 6 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

12 encounter any surficial deleterious organic material. The manual probes, however, cannot detect peat or muck layers which may be present beneath layers of sand or dense soils which cannot be penetrated by the probe. Please refer to the Boring Results sheets (Figures and 4) and the Muck Probe Location Plan with Results (Figure 5) in the Appendix for the specific subsurface profiles at the boring and probe locations. 6.2 Groundwater Levels Groundwater levels were encountered at the SPT and auger boring locations at depths ranging from approximately 0. to. feet below existing ground surface. However, at boring location HA- 1 groundwater was encountered at approximately 1-foot above the existing ground surface. At boring locations TB-1 and TB-2, groundwater was encountered at approximately 6 feet below the existing ground surface. Groundwater levels can vary seasonally and with changes in subsurface conditions between boring locations. Alterations in surface and/or subsurface drainage brought about by site development can also affect groundwater levels. Therefore, groundwater depths measured at different times or at different locations on the site can be expected to vary from those measured by GEC during this investigation. For purposes of this report, estimated seasonal high groundwater levels are defined as groundwater levels that are anticipated at the end of the wet season during a normal rainfall year under pre-development site conditions. We define a normal rainfall year as a year in which rainfall quantity and distribution were at or near historical averages. Seasonal high groundwater depths typically range from the ground surface to approximately 1-foot below existing ground Seasonal high groundwater depths were estimated at borings where groundwater was encountered and typically range from the ground surface to approximately 1-foot below existing ground at our boring locations. However, the seasonal high groundwater depth for borings HA-1, HA-2 and B-1 is estimated to be above the ground surface, indicated by AGS shown adjacent to the boring profile. Additionally, the seasonal high groundwater depth for borings TB-1 and TB-2 is estimated to be 4 feet below the existing ground surface. The encountered and estimated seasonal high groundwater levels are presented on the Boring Results sheets (Figures and 4) in the Appendix. GEC Project No. 956G 7 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

13 7.0 CONCLUSIONS AND DESIGN RECOMMENDATIONS The conclusions and design recommendations contained in this report are based in part on the data obtained from a limited number of soil samples and the groundwater measurements obtained from widely-spaced borings. The sampling methods used indicate subsurface conditions only at the specific boring locations where samples were obtained, only at the time they were obtained, and only to the depths penetrated. Borings cannot be relied upon to accurately reflect the variations that usually exist between boring locations and these variations may not become evident until construction. If variations from the subsurface conditions described in this report do become evident during construction or if the project characteristics described in this report change, GEC should be retained to reevaluate this report s conclusions and recommendations in light of such changes. 7.1 Foundations On the basis of the data obtained for this study, in our opinion the site is suitable for support of the proposed toll structures upon a system of conventional shallow isolated spread footings and/or continuous strip footings or thickened edge monolithic slabs. This conclusion is contingent upon the design engineer s and contractor's adherence to the following recommendations: Prepare the structure area in accordance with the recommendations in the General Site Preparation and Fill Selection, Placement and Compaction sections of this report after final site grading has been performed. Prepare footing subgrade soils in accordance with the recommendations presented in the Foundation Subgrade Preparation section of this report. Use a maximum net allowable soil bearing pressure of,000 pounds per square foot Use a maximum net allowable soil bearing pressure of,000 pounds per square foot in footing design. Use minimum footing dimensions of 24 inches for isolated spread footings and 18 inches for strip footings even though the maximum net soil bearing pressure may not be fully developed in all cases. GEC Project No. 956G 8 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

14 Design spread and/or strip foundations so that footings bear at least 18 inches below the adjacent finished exterior grades. Design monolithic slabs so that the bottom of thickened slab sections bear at least 12 inches below the adjacent finished exterior grade. Support floor slabs constructed on-grade on a compacted sand base (95% modified Proctor for 12 inches). Overexcavate excessively loose or disturbed soils encountered in the floor slab areas and replace with sands selected and compacted in accordance with the Fill Selection, Placement and Compaction section of this report. Our evaluation of the encountered subsurface conditions indicates that shallow foundations designed and constructed in accordance with the above recommendations, assuming supporting loads no heavier than those typical of a one-story building, will experience total settlements of less than approximately 1 inch and differential settlements between footings of less than ½ inch. 7.2 Pavements Our study results indicate that the site is suitable for support of conventional flexible or rigid pavement sections. Flexible pavements can incorporate a limerock base material if at least 2 feet of vertical separation is provided between the bottom of the limerock base and the seasonal high groundwater level. A soil-cement base, reclaimed concrete aggregate (RCA) base or asphalt base material (black base) should be used if this vertical clearance cannot be provided. Furthermore, pavement underdrains will be needed if seasonal high groundwater levels are within 1-foot of the bottom of base. These conclusions are contingent upon preparation of proposed pavement areas in accordance with GEC s recommendations in the General Site Preparation; Fill Selection, Placement and Compaction; and Pavement Subgrade Preparation sections of this report. This includes removing and replacing any organic soils, if encountered within 2 feet of the bottom of the pavement base. No deleterious organic soils were encountered at our boring locations shown on Figure 2. The following recommended minimum pavement sections are typical of similar projects in this area and are not based on any traffic loading information or formal pavement design, since such information is not available: GEC Project No. 956G 9 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

15 For light duty usage, such as automobile parking stalls, we recommend the following minimum pavement section: 1.5 inches of Structural Asphalt Surface Course. 6 inches of limerock (minimum LBR 100) or 8 inches of soil-cement (minimum 00 psi) or 6 inches of RCA (minimum LBR 150) base course. 12 inches of stabilized subgrade (LBR=40) if limerock or RCA is used. For heavy duty usage, such as interior parking lot driveways and perimeter roads, we recommend the following minimum pavement section: 2 inches of Structural Asphalt Surface Course. 8 inches of limerock (minimum LBR 100) or 10 inches of soil-cement (minimum 00 psi) or 8 inches of RCA (minimum LBR 150) base course. 12 inches of stabilized subgrade (LBR=40) if limerock or RCA is used. For heavy duty usage requiring a concrete pavement section, such as loading docks, we recommend the following: 6 inches of concrete, 4,000 psi (28-day minimum). Compact the 12-inch subgrade beneath the concrete to a minimum of 98% of ASTM D-1557 maximum density. Concrete pavement design, including jointing of the pavement, should comply with the specifications of the Portland Cement Association (PCA). Well-drained soils (unified classification SP) must be utilized beneath the concrete pavement. A minimum clearance of 18 inches must be maintained between the bottom of concrete pavement and the seasonal high water table. Reclaimed concrete aggregate base material should meet the specifications of the state or local jurisdiction. If a specification for reclaimed concrete aggregate base is not available, GEC recommends the following minimum specifications be included in the project specifications: Reclaimed concrete aggregate base material should meet the following gradation requirement: GEC Project No. 956G 10 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

16 Sieve Size Percent by Weight Passing 2 inch 100 /4 inch 65 to 95 /8 inch 40 to 85 No to 65 No to 50 No to 25 No to 10 The reclaimed concrete aggregate base should consist of crushed concrete material derived from the crushing of hard Portland cement concrete. Reclaimed concrete aggregate base should not contain plastic soils (i.e.; the minus mm (No. 40) sieve material should be non-plastic). Reclaimed concrete aggregate base should have a minimum limerock bearing ratio (LBR) of 120. Reclaimed concrete aggregate base should be free of all materials that fall under the category of solid waste or hazardous materials as defined by the state or local jurisdiction and should meet all Department of Environmental Protection (DEP) permit requirements which pertain to construction, demolition and recycling of these materials. Reclaimed concrete aggregate base should also be substantially free from other deleterious materials which are not classified as solid waste or hazardous materials and be asbestos free. The following limits should not be exceeded: Deleterious Material Percent by Weight Bituminous Concrete 1 Bricks 1 Wood and other Organic Substances 0.1 Heavy Metals (except Lead) 0.1 Lead 5 ppm Reinforcing Steel and Welded Wire Fabric 0.1 Plaster and Gypsum Board 0.1 The reclaimed concrete aggregate base supplier should have DEP permit requirements section or be qualified as a clean debris source under DEP rules. GEC Project No. 956G 11 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

17 7. Unpaved Access Road for Pond SAR-D Our study results indicate that the site can be made suitable for the proposed unpaved driveway that is located along the southern end of Pond SAR-D. Our conclusions are contingent upon preparation of proposed pavement areas in accordance with GEC s recommendations in the General Site Preparation; Fill Selection, Placement and Compaction; and Pavement Subgrade Preparation sections of this report. We understand that the following section will be used for the unpaved driveway. 4 inches of sand stabilized with limerock, shell and/or clay (LBR 100) compacted to 98% of the modified proctor (ASTM D-1557) maximum density. 12 inches of stabilized subgrade (LBR=40). A minimum vertical clearance of 18 inches between the bottom of the stabilized layer and the seasonal high groundwater level is recommended. Provide adequate grading for positive surface drainage to promote drainage of surface water from the roadway to reduce water ponding. Unpaved roadways will likely need more maintenance (i.e.; regrading, leveling, etc.). 7.4 Stormwater Pond Weir Structure GEC understands the proposed 48-foot long concrete weir structure will be constructed on 12 inches of stabilized subgrade (LBR 40). We recommend that the weir footprint area be prepared in accordance with GEC s recommendations in the General Site Preparation; Fill selection, Placement and Compaction; and Foundation Subgrade Preparation section of this report. Soil and groundwater corrosion series test results at the weir structure are presented in Table 8 in the Appendix. GEC understands the skimmer poles will be designed using subsurface data and soil strength parameters provided in this report. Based on our boring results, the soils appear appropriate for construction of the skimmer poles. The soil parameters shown below can be used in designing the skimmer poles. GEC Project No. 956G 12 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

18 Table 5 Soil Parameters for Design of Skimmer Poles Soil Type Depth Below Existing Ground Surface (feet) Soil Unit Weight (pcf) Moist Saturated Effective Soil Angle of Internal Friction (φ) Cohesion (psf) General N-Value Range Average N Value (blows/foot) Sand Clay , Estimated Seasonal High Groundwater Table Depth (feet) AGS 1. AGS denotes the groundwater level is estimated to be above the existing ground surface. The height to which water may rise above the ground surface should be determined by the drainage engineer. 7.5 Lateral Earth Pressures This section is for use in design of the proposed below ground structures included in the site design. These recommendations are applicable for structures embedded in the surficial sandy soils encountered above about 20 feet deep at the site. Lateral earth pressure for design of below grade structures can be calculated using a hydrostatic pressure distribution from an equivalent fluid having varying densities for various conditions. These values assume sandy soil with an angle of internal friction of about 0 degrees, a moist unit weight of 110 pcf and a saturated unit weight of 115 pcf. The table below summarizes the recommended equivalent fluid densities for active, passive and at-rest conditions and drained or undrained conditions. The actual lateral earth pressure will be a function of both the soil unit weight (submerged or moist) and the depth below ground surface. Table 6 Lateral Earth Pressures Lateral Earth Pressure Condition Equivalent Fluid Density Undrained (pcf) Equivalent Fluid Density Drained (pcf) Active 79 6 Passive* At-Rest *Note This value is a recommended conservative Equivalent Fluid Density that does not allow the hydrostatic pressure to contribute to passive earth pressure. Undrained conditions assume that full water pressure can develop behind the structure, in addition to the retained earth pressure. This condition should be used if groundwater can occur at the elevation of the top of the structure. Drained conditions assume no hydrostatic (water) GEC Project No. 956G 1 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

19 pressure can develop due to positive drainage behind the structure, and includes only the moist soil earth pressure. Frictional resistance at the bottom of the structures to limit sliding can be calculated by multiplying the bottom contact pressure by a coefficient of friction of 0.5. We note that the values for earth pressure and frictional resistance do not contain a factor of safety. We have conservatively assumed that hydrostatic pressure does not contribute to passive earth pressure. Appropriate factors of safety should be selected by the structural engineer providing the structural design. 7.6 Uplift Resistance Permanent structures submerged below the water table will be subjected to uplift forces caused by buoyancy. The components resisting this buoyancy include: 1) the total weight of the structure divided by an appropriate factor of safety; 2) the buoyant weight of soil overlying the structure; and ) the shearing forces that act on shear planes that radiate vertically upward from the edges of the structure to the ground surface. The allowable unit shearing resistance may be determined by the following formula: Where: Allowable Unit Shearing Resistance, F = K o γ m h (2/ tanφ)/s.f. (Above groundwater table) Allowable Unit Shearing Resistance, F = K o (γ s - γ W ) h (2/ tanφ)/s.f. (Below groundwater table) F = unit shearing resistance (psf) K o = coefficient of earth pressure at rest = 0.5 γ m = unit weight of moist soil = 110 pcf γ s = saturated unit weight of soil = 115 pcf γ W = unit weight of water = 62.4 pcf h = vertical depth below grade at which shearing resistance is determined Φ = angle of internal friction of the soil = 0 degrees S.F. = safety factor = 1.5 GEC Project No. 956G 14 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

20 For this uplift design we recommend assuming groundwater at the ground surface. The values given for the above parameters assume that the permanent structure is covered by clean, well compacted granular backfill that extends horizontally at least 5 feet beyond the structures. For this uplift design we recommend a worst case scenario of assuming groundwater at the ground surface. An appropriate safety factor should also be included in the design of the structure. 8.0 CONSTRUCTION ISSUES The following sections of this report include comments on issues related to the geotechnical aspects of the proposed construction. These recommendations are not intended to dictate construction methods or sequences. Instead, they are furnished as an aid to design professionals and to identify important construction issues related to foundation and earthwork plans and specifications. These recommendations may also be useful to personnel who observe construction activity. Prospective contractors for this project should evaluate potential construction problems on the basis of their review of the contract documents, their own knowledge and experience in the local area, and on the basis of similar projects in other localities, taking into account their own proposed means and methods. 8.1 General Site Preparation Our recommendations regarding routine site preparation of the structure and pavement areas can be summarized as follows: Remove all vegetation, organic topsoil, major root systems, buried utilities, and other deleterious materials from beneath and to a minimum of 5 feet beyond the proposed structure and pavement limits. Standard clearing, grubbing, and topsoil stripping procedures should be appropriate for most of this site. Perform temporary dewatering as required to achieve proper site preparation, fill placement and compaction. Allow a Geotechnical Engineer to inspect the site after it has been stripped to verify adequate topsoil and vegetation removal and also to observe subsequent proofrolling. GEC Project No. 956G 15 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

21 In structure and pavement areas where fill is required, proofroll the stripped ground surface using a large vibratory roller (Dynapac CA-25 or equivalent). Proofroll cut areas after excavation to proposed grade to allow adequate compaction of the exposed subsoil. Exercise extreme caution when operating vibratory equipment near existing structures. Nearby structures may be adversely affected by vibratory rolling operations. Provisions should be made to monitor adjacent buildings for excessive vibrations. Operate roller in static mode if excessive vibrations are experienced by any nearby structures or if the soil subgrade becomes unstable. Proofroll the structure and pavement areas with a minimum of 10 overlapping passes in each of two perpendicular directions. Allow a Geotechnical Engineer, or his representative, to observe proofrolling operations. The purposes of the proofrolling will be to detect unstable soils that yield when subjected to compaction and to densify the near-surface loose sands for support of shallow foundations, soil supported floor slabs, and new pavements. Remove material that yields excessively during proofrolling and replace with fill selected and compacted as described in the next section of this report. The Geotechnical Engineer, based on his observations, should recommend the nature and extent of any remedial work. If the soil subgrade is saturated, or if the fill is at a moisture content over optimum, then instability may occur and the contractor will be required to implement remedial measures to successfully place and compact the fill. Silty sand (SM) may be exposed at the compaction surface during site preparation. These soils can be unstable during proofrolling if they contain excess moisture. The contractor should be prepared to manipulate the moisture content of unstable subgrade soils as necessary to achieve stability and compaction requirements. Continue proofrolling until the soil at a depth of 12 inches below the compaction surface has attained a minimum of 95% of the soil's modified Proctor maximum dry density as determined by ASTM Standard D Allow an Engineering Technician, working under the direction of a Geotechnical Engineer registered in the State of Florida, to perform in-place density tests to verify that the required degree of compaction has been achieved. GEC Project No. 956G 16 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

22 8.2 Fill Selection, Placement and Compaction After the contractor proofrolls the site in accordance with the above recommendations, the contractor should place and compact fill required to bring the site to final grade. We recommend that all fill be selected, placed and compacted as follows: Use fill material comprised of non-plastic sands with less than about 12% fines content. The fill should not contain any significant amount of organic soil (less than % by weight) and should be substantially free from roots or other organic or deleterious materials. Sands excavated above the water table may have to be wetted to attain the moisture content needed to achieve the required degree of compaction. Place fill in level lifts no thicker than 12 inches. Thinner lifts may be needed to achieve compaction in the silty sand. Compact fill to a minimum of 95% of the soil's modified Proctor maximum dry density as determined by ASTM Standard D-1557 for each lift of fill placed. Allow an Engineering Technician, working under the direction of a registered Geotechnical Engineer, to perform in-place density tests to verify that the recommended degree of compaction has been achieved. Extend fill a minimum of 10 feet beyond building limits to prevent possible erosion or undermining of footing bearing soils. Provide fill slopes no steeper than 2 horizontal to 1 vertical. Compact fill placed in utility trenches to the specifications stated above. However, in restricted working areas, where use of a large vibratory roller is not feasible, compact fill with lightweight, hand-guided compaction equipment and limit lift thicknesses to a maximum of 6 inches. All excavations including utility trenches, should comply with the recommendations included in the Temporary Excavations section of this report. GEC Project No. 956G 17 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

23 8. Foundation Subgrade Preparation We recommend the following steps be taken during footing excavation and subgrade preparation: Excavate footings in accordance with the recommendations presented in the Temporary Excavations section of this report. Compact footing subgrade soils to a depth of 12 inches below footing/structure bearing elevations to a minimum of 95% of the soil's modified Proctor maximum dry density as determined by ASTM Standard D Perform in-place density tests at 12 inches below the footing bearing elevation to verify footing subgrade density. Allow a Geotechnical Engineer, or his representative, to observe footing excavation conditions prior to placement of reinforcing steel or concrete. On the basis of the Geotechnical Engineer's observations, remove any unsuitable material encountered in the footing excavations and replace with sand selected and compacted in accordance with the Fill Selection, Placement and Compaction section of this report. 8.4 Pavement Subgrade Preparation Our general recommendations for the pavement subgrade are as follows: Prepare pavement areas in accordance with the General Site Preparation and Fill Selection, Placement and Compaction sections of this report. Compact the 12-inch subgrade beneath the base to a minimum of 98% of ASTM D-1557 maximum density. Perform in-place density tests to verify pavement subgrade density. Stabilize the subgrade beneath a limerock or RCA base to a minimum Limerock Bearing Ratio (LBR) of 40. Stabilization is not required beneath a soil-cement base or rigid (concrete) pavement. However, the lack of subgrade stabilization should be considered in the pavement design. GEC Project No. 956G 18 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

24 8.5 Temporary Dewatering Depending on groundwater levels at the time of construction, excavation depths and final design grades, temporary dewatering may be required to facilitate stable excavations and placement and compaction of fill. The contractor should be required to provide a dewatering system which maintains groundwater levels at least 2 feet below compaction surfaces, including the bottom of all excavations. A system of ditches and sumps may be sufficient in some instances to achieve adequate dewatering, but the contractor should be prepared to install wellpoint dewatering systems as necessary. Additionally, the contractor must provide positive site drainage during the site preparation and fill placement. Surface runoff should not be allowed to accumulate. Temporary rim ditches may be required to facilitate site preparation. 8.6 Temporary Excavations The owner and the contractor should be familiar with local, state and federal safety regulations, including current Occupational Safety and Health Administration (OSHA) excavation and trench safety standards. Construction site safety is the responsibility of the contractor. The contractor should also be responsible for the means, methods, techniques, sequences, and operations of the construction. The contractor should be aware that slope height, slope inclination, and excavation depths (including utility trench excavations) should not exceed those specified in local, state, or federal safety regulations; e.g., OSHA Health and Safety Standards for Excavations, 29 CFR Part OSHA regulations are strictly enforced and, if not followed, the owner, contractor, earthwork subcontractor or utility subcontractor could be liable for substantial penalties. The soil encountered in the borings performed by GEC at this site is primarily sand with varying amounts of silt. We anticipate that OSHA will classify these materials as Type C. OSHA recommends a maximum temporary slope inclination of 1.5 horizontal to 1 vertical for this soil type. Soils encountered in the construction excavations may vary significantly across the site. Our soil classifications are based on the materials encountered in widely-spaced borings. The contractor should verify that similar conditions exist throughout the proposed excavation area. If different subsurface conditions are encountered at the time of construction, GEC should be contacted immediately to evaluate the conditions encountered. GEC Project No. 956G 19 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

25 9.0 USE OF THIS REPORT GEC has prepared this report for the exclusive use of our client, American Infrastructure Development, Inc., and for specific application to our client s project. GEC will not be held responsible for any third party s interpretation or use of this report s subsurface data or engineering analysis without our written authorization. The sole purpose of the borings performed by GEC at this site was to obtain indications of subsurface conditions as part of a geotechnical exploration program. GEC has not subjected any soil samples to analysis for contaminants. GEC has strived to provide the services described in this report in a manner consistent with that level of care and skill ordinarily exercised by members of our profession currently practicing in Central Florida. No other representation is made or implied in this document. The conclusions or recommendations of this report should be disregarded if the nature, design, or location of the facilities is changed. If such changes are contemplated, GEC should be retained to review the new plans to assess the applicability of this report in light of proposed changes. GEC Project No. 956G 20 Report of Geotechnical Engineering Investigation OIA South Cell Lot (W40)

26 APPENDIX

27 USGS QUADRANGLE AND NRCS SOIL SURVEY MAPS

28 Approximate Project Site USGS Pine Castle, FL Quadrangle Map Section: 10 Township: 24 South Range: 0 East : 0 1,000 2,000 Feet Approximate Project Site NRCS Soil Survey of Orange County, FL 7Orange County Map Unit Legend - Basinger fine sand, depressional, 0 to 1 percent slopes 26 - Ona 99fine sand, 0 to 2 percent slopes Pomello fine sand, 0 to 5 percent slopes Smyrna-Smyrna, wet, fine sand, 0 to 2 percent 4 slopes Geotechnical and Environmental Consultants, Inc. GEC 919 Lake Baldwin Lane Orlando, FL 2814 PH (407) FAX (407) Certificate of Authorization No CHRISTOPHER P. MEYER P.E. NO PROJECT NO. 956G DATE 7/6/2017 DRAWN BY SKR CHECKED BY VEW CHECKED BY CPM 4928 USGS QUADRANGLE AND NRCS SOIL SURVEY MAPS OIA SOUTH CELL LOT FIGURE NO. J:\Jobs - Drafting\956G OIA Cell Lot\956Gmaps.mxd 7/6/2017 1

29 BORING LOCATION PLAN

30 PROPOSED CELL LOT AREA < HA-7 & < HA-5 & < HA- & & HA-4 < & HA-1 < & HA-2 < < HA-8 & & HA-6 < < HA-9 & < HA-10 & CE LA P K AR HP T U SO & TB-1 < < TB-2 & PROPOSED TOLL BOOTH PROPOSED TOLL BOOTH B-1 && < < B-2 PROPOSED WEIR STRUCTURE < & APPROXIMATE SPT BORING LOCATION & APPROXIMATE AUGER BORING LOCATION < Feet 200 : GEC Geotechnical and Environmental Consultants, Inc. 919 Lake Baldwin Lane Orlando, FL 2814 PH (407) FAX (407) Certificate of Authorization No CHRISTOPHER P. MEYER P.E. NO PROJECT NO. 956G DATE 7/6/2017 DRAWN BY SKR CHECKED BY VEW CHECKED BY CPM 4928 BORING LOCATION PLAN OIA SOUTH CELL LOT FIGURE NO. 2 J:\Jobs - Drafting\956G OIA Cell Lot\956G.mxd 7/6/2017

31 BORING RESULTS

32

33

34 MUCK PROBE LOCATION PLAN WITH RESULTS

35 &< HA-10 & &< HA-7 &< HA- &< HA-5 &< HA-8 &< HA-2 &< HA-4 &< HA-6 &< HA-9 &< HA-10 &. & &. SEE MUCK PROBE LOCATION 'A' DETAIL &< TB-1 &< TB-2 MUCK PROBE LOCATION 'A' DETAIL Feet & & &. & & &< B &. & & &< B-2 &. B-1 &.&.&. &.&. &. B-2 &< &< SEE MUCK PROBE LOCATION 'B' DETAIL MUCK PROBE LOCATION 'B' DETAIL SOFT SEDIMENT / SAND STANDING WATER DEPTH (FT.) SURFICIAL MUCK THICKNESS (FT.) &< &< &. APPROXIMATE SPT BORING LOCATION APPROXIMATE AUGER BORING LOCATION APPROXIMATE LOCATION OF MUCK PROBE Feet : 919 Geotechnical and Environmental Consultants, Inc. GEC Lake Baldwin Lane Orlando, FL 2814 PH (407) FAX (407) Certificate of Authorization No CHRISTOPHER P. MEYER P.E. NO PROJECT NO. 956G DATE 7/6/2017 DRAWN BY SKR CHECKED BY VEW CHECKED BY CPM 4928 MUCK PROBE LOCATION PLAN WITH RESULTS OIA SOUTH CELL LOT Feet FIGURE NO. J:\Jobs - Drafting\956G OIA Cell Lot\956Gprobe.mxd 7/6/2017 5

36 SUMMARY OF LABORATORY TEST RESULTS

37 Table 7 Summary of Laboratory Test Results OIA South Cell Lot (W40) GEC Project No. 956G Page 1 of 1 Sample Percent Passing by Weight Moisture Atterberg Limits Organic Boring Depth #10 #40 #60 #100 #200 Content Liquid Plasticity Content Unified No. (feet) Sieve Sieve Sieve Sieve Sieve (%) Limit Index (%) Class. HA SP-SM HA SP-SM HA SP-SM HA SP-SM HA SM

38 SUMMARY OF CORROSION SERIES TEST RESULTS

39 Table 8 Summary of Corrosion Series Test Results OIA South Cell Lot (W40) GEC Project No. 956G Page 1 of 1 Boring No. Unified Soil Classification Sample Depth (feet) ph Minimum Resistivity (ohm-cm) Chlorides (ppm) Sulfates (ppm) Substructural Environmental Classification Concrete B-1 Water , Slightly Aggressive Slightly Aggressive B-2 SM , < 5 Slightly Aggressive Moderately Aggressive Steel