TABLE OF CONTENTS. 5.0 LABORATORY TESTING Corrosion Series Testing Consolidation Testing... 5

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3 TABLE OF CONTENTS 1.0 SITE AND PROJECT DESCRIPTION NRCS SOIL SURVEY USGS POTENTIOMETRIC MAP DATA SUBSURFACE EXPLORATION SPT Borings Groundwater Measurement Undisturbed Samples Corrosion Sampling LABORATORY TESTING Corrosion Series Testing Consolidation Testing DESCRIPTION OF SUBSURFACE CONDITIONS Soil Strata Groundwater Levels ANALYSIS AND DESIGN RECOMMENDATIONS Levee Embankment Sheet Pile Analysis Control Structure Foundations CONSTRUCTION ISSUES Temporary Dewatering General Site Preparation Fill Selection, Placement and Compaction Shallow Foundation Subgrade Preparation Temporary Excavations QUALITY ASSURANCE USE OF THIS REPORT GEC Project No. 3506G ii Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

4 APPENDIX Figure 1: USGS Quadrangle and NRCS Soil Survey Maps Figure 2: Boring Location Plan Figures 3 and 4: Boring Results Table 3: Summary of Laboratory Test Results Table 4: Summary of Corrosion Series Test Results Consolidation Curves WINSAF-I Output PCSTABL Output Cantilever Steel Sheet Pile Data Table CWALSHT Output GEC Project No. 3506G iii Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

5 1.0 SITE AND PROJECT DESCRIPTION Fodderstack Slough is located on the west side of Lake Marian in the Three Lakes Wildlife Management Area in southern Osceola County, Florida. This area is an existing slough that connects Lake Marian and the Jackson Canal. The approximate site vicinity is shown on excerpts of the United States Geological Survey (USGS) Lake Marian NW, Florida and Lake Marian SW, Florida Quadrangle maps on Figure 1 in the Appendix. Based on a review of the USGS Quadrangle map, the ground surface elevation across the site is approximately +60 feet NGVD. Project plans include a 600 foot long concrete capped, steel sheet pile weir centrally located across Fodderstack Slough between two levee embankments Project plans include the Fodderstack Slough Weir Structure, which will span approximately 1,050 feet across the slough between Lake Marian and the Jackson Canal. It is expected to consist of a 600 foot long concrete capped, steel sheet pile weir, approximately 4 feet high. The sheet pile structure will be centrally located across Fodderstack Slough between two levee embankments; one about 135 feet long (north side) and the other about 320 feet long (south side). Each levee will range in height from approximately 0 to 4 feet high and will have a top width of 14 feet. The transitions between the weir sheet pile structure and the levee embankments will include a concrete capped, abutment steel sheet pile. Additionally, a central control structure, consisting of a 5 ft by 10 ft platform and a 30-inch wide foot bridge, is proposed located along the center of the sheet pile weir crossing. According to the project plans, the control structure will be supported on a concrete monolithic slab foundation with thickened edges. 2.0 NRCS SOIL SURVEY The Natural Resources Conservation Service (NRCS) Soil Survey of Osceola County, Florida was reviewed for near-surface soil and groundwater information within the vicinity of the subject site. The NRCS Soil Survey map of the site vicinity is shown on Figure 1 in the Appendix. The NRCS soils near the project site are summarized on the following table: GEC Project No. 3506G 1 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

6 Unit No. 10 Soil Name Delray loamy fine sand, depressional 14 Holopaw fine sand 16 Immokalee fine sand Depth (inches) Table 1 NRCS Soil Survey Classifications Soil Description Loamy fine sand Fine sand Fine sandy loam, sandy clay loam Loamy fine sand, fine sandy loam Fine sand Fine sand Sandy clay loam, sandy loam, fine sandy loam Loamy sand, loamy fine sand, fine sand Fine sand Fine sand Fine sand Fine sand + indicates ponding water depth above the ground surface. Unified Classification Symbol SC-SM, SM, SP-SM SP-SM SC, SC-SM, SM SC-SM, SM, SP-SM SP-SM, SP SP, SP-SM SM, SC-SM SP-SM, SM SP-SM, SP SP-SM, SP SM, SP-SM SP-SM, SP Depth to Seasonal High Groundwater (feet) According to the Soil Survey, the predominant soil type in this slough is Delray loamy fine sand which consists of about 14 inches of black loamy sand underlain by layers of sand, sandy loam and sandy clay loam. Delray loamy fine sand typically has a groundwater table of less than the 10 inches below the existing ground surface, with standing water between 2 and 6 months of the year. Information contained in the NRCS Soil Survey is very general and may be outdated. Therefore, it may not 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. 3.0 USGS POTENTIOMETRIC MAP DATA Based on the USGS map entitled The Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, May 2009 the potentiometric level of the Floridan aquifer in the vicinity of the subject site ranges from approximately +40 to +50 GEC Project No. 3506G 2 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

7 feet NGVD. Since the existing ground surface elevation in the vicinity of the subject site is approximately +60 feet NGVD, artesian flow conditions may be encountered depending on the depths of excavation(s) and sheet pile wall penetration. However, artesian conditions were not encountered in our soil borings. 4.0 SUBSURFACE EXPLORATION GEC explored subsurface In addition to consulting the sources of information previously conditions by performing discussed for regional and site-specific soils data, GEC conducted six SPT borings a subsurface exploration to evaluate soil and groundwater conditions. GEC explored subsurface conditions at the subject site by performing six Standard Penetration Test (SPT) borings (B-1 through B-6) to depths of 30 feet below existing ground (or 35 feet below the barge deck on some borings) within the proposed berm and weir footprint. The approximate locations of the borings performed for this study are shown on Figure 2 in the Appendix. These locations were surveyed by F.R.S. & Associates, Inc. for horizontal and vertical control. 4.1 SPT Borings Standard Penetration Test (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 help remove cuttings and to help stabilize the borehole. Casing was used as necessary to further stabilize the borehole and prevent loose surficial sands from raveling into the lower more stable portions of 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 supervised the drilling operation, and collected, examined and visually classified each sample. A field SPT boring log was completed by the technician that described the soils penetrated, reported the SPT blow counts for each 6 inch increment tested, recorded the groundwater, and included other details of the boring methods used, and detailed other boring and/or site conditions at the time of drilling. Our technician collected representative samples for further visual examination and classification in our laboratory. GEC Project No. 3506G 3 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

8 4.2 Groundwater Measurement 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. 4.3 Undisturbed Samples A total of six representative undisturbed samples of sandy, organic or cohesive soils were collected from the six borings (one sample per boring) at depths ranging between 2 feet and 27 feet below existing ground surface using a thin-walled Shelby tube sampler. The sampler is hydraulically pushed into the soil at the desired depth. After allowing the sampler to sit for a short time it is retrieved from the borehole where the soil at the top and bottom of the tube is sampled and classified. The 3-inch diameter tube is then moisture sealed in the field immediately after sampling and returned to our laboratory for further examination and testing. 4.4 Corrosion Sampling A total of 3 samples (two soil and one water) were obtained for corrosion testing. The soil samples were obtained adjacent to boring locations B-2 and B-5. The samples were obtained from depths of about 0.5 to 1.5 feet and 6 to 12 feet, respectively. The water sample was collected near the B-3 boring location. The samples were immediately placed in glass jars and returned to our laboratory for corrosion testing. 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 has been reviewed by the Army Corps of Engineers (COE) and the Construction Materials Engineering Council (CMEC). The laboratory testing program for this project is summarized in the following table: GEC Project No. 3506G 4 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

9 Table 2 Summary of Laboratory Testing Program Number of Type of Test Tests Percent Fines (FM 1 - T88) 5 Grain Size Analysis (FM 1 - T88) 16 Atterberg Limits (FM 1 - T89/90) 4 Specific Gravity (FM 1 - T100) 1 Natural Moisture Content (FM 1 - T265) 21 Organic Content (FM 1 - T267) 2 Corrosion Series (ph, sulfates, chlorides, and resistivity) (FM 5-550, 5-551, and 5-553) 3 Consolidation Test (ASTM D-2435) 1 Unit Weight (ASTM D ) 1 The results of our laboratory testing are presented adjacent to the soil boring profiles on the Boring Results sheets (Figures 3 and 4) and are also summarized on Table 3 in the Appendix. 5.1 Corrosion Series Testing The results of our corrosion series tests are presented on Table 4 in the Appendix. Based on the results, we recommend using a substructural environmental classification of Moderately Aggressive for concrete and Extremely Aggressive for steel. 5.2 Consolidation Testing A portion of the undisturbed sample of sandy clay obtained at boring location B-1 (25 to 27 feet) was sampled for one-dimensional consolidation testing in general accordance with ASTM-D2435. Undisturbed samples selected for testing are carefully trimmed and placed in the fixed ring consolidometer. A seating pressure of about 100 psf is applied and the sample is inundated in water. The sample submergence is maintained throughout the test. The sample is then incrementally loaded and deflections are monitored. Each incremental load is maintained until internal pore pressures are dissipated as indicated by a flattening of the timedeflection curve. A rebound of the sample is provided at a selected load increment when the sample is unloaded and reloaded to obtain further details of the loading characteristics of the soil. GEC Project No. 3506G 5 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

10 The data obtained during incremental loading is reduced and a semi-log plot of sample void ratio versus applied stress is created. A copy of this curve is included in the Appendix of this report. This curve is utilized to estimate the magnitude of settlement that will be induced by anticipated site loadings. The curve is also used to estimate the pre-consolidation pressure (Pc) and the overconsolidation ratio (OCR) of the soil tested. 6.0 DESCRIPTION OF SUBSURFACE CONDITIONS Figures 3 and 4 document the SPT boring results. These figures 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 test results shown. 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 purposes. Earthwork quantity estimates based on the results of the borings will vary from the actual quantities measured during construction. 6.1 Soil Strata The SPT borings typically encountered loose to medium dense fine sand with varying amounts of silt content (SP, SP-SM, SM) The SPT borings typically encountered loose to medium dense fine sand with varying amounts of silt content (SP, SP-SM, SM) to the boring termination depths of 30 feet below existing ground. However, boring B-1 encountered loose clayey fine sand (SC) to firm sandy lean clay (CL) from about 23.5 to 26.5 feet below existing ground surface, and boring B-2 encountered loose clayey fine sand from 23.5 to 28.5 feet below the ground surface. Additionally, borings B-3 and B-4 encountered very soft sandy muck (PT) from ground surface to a depth of 4 feet and 2 feet, respectively. Also, borings B- 3 and B-4 encountered very loose fine sand with silt (with trace organic material in boring B-3) GEC Project No. 3506G 6 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

11 beneath the surficial PT layer to a depth of 6 feet. Approximately 6 inches of organic topsoil was encountered in borings B-1, B-2 and B-5 and trace roots were encountered in borings B-1, B-2 and B-6 at various depths. Please refer to the Boring Results sheets (Figures 3 and 4) in the Appendix for the specific subsurface profile at the boring locations. 6.2 Groundwater Levels Our technician identified the stabilized groundwater surface in the SPT boreholes at depths ranging from above the ground surface to about 2 feet below existing grade during our most recent field exploration. Groundwater elevations measured at all boreholes are presented in Figures 3 and 4 in the Appendix. The groundwater elevations presented on these figures are based on surveyed ground surface elevations at each borehole location and the depth to groundwater measured by our technician in the field. 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. We estimate seasonal high groundwater levels will be above the ground surface We estimate seasonal high groundwater levels will be above the ground surface at all six boring locations. Our estimated seasonal high groundwater levels are presented on Figures 3 and 4 in the Appendix. 7.0 ANALYSIS AND DESIGN RECOMMENDATIONS The analyses and recommendations contained in this report are based in part on the data obtained from a limited number of soil samples and groundwater measurements obtained from widelyspaced 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 GEC Project No. 3506G 7 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

12 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 and modify the recommendations included in this report, if needed, in light of such changes. We also recommend that GEC be allowed to review the construction plans prior to bidding so that we can verify that our recommendations were properly interpreted. the surficial sandy muck must be removed prior to placement of fill. Based on the results of the subsurface soil investigation, the majority of the soils encountered in our borings appear suitable for the construction of the proposed berm and weir structure. However, the surficial sandy muck (PT) layer as encountered in borings B-3 and B-4 must be removed prior to placement of fill. The remainder of the underlying soils do not present any significant challenges regarding the settlement or stability of the proposed weir structure and embankment. Our recommendations for these are provided below. 7.1 Levee Embankment We understand the earthen levee embankment is only proposed on the north 135 feet and south 300 feet of the Fodderstack Slough and levee heights above natural ground will range from 0 to 4 includes the removal of any surficial organic materials. feet high. The footprint of the levees must be prepared in accordance with the recommendations in this report which includes the removal of any surficial organic materials. GEC conducted settlement analyses to calculate the total estimated embankment settlement (including the primary consolidation of the buried sandy clay soil layer) using the computer program WINSAF-I. Total settlement due to the proposed 4 foot levee embankment resulted in a maximum settlement of less than 1.5 inches. We estimate that the majority of this settlement will occur during placement of the fill. The WINSAF-I program output is included in the Appendix. Due to the height of the proposed embankment and the nature of the cohesive soil, we do not anticipate significant secondary consolidation settlement. GEC used the computer program PCSTABL6H for the global stability analysis of the levee embankments (with 3H:1V side slopes). Our analysis resulted in a factor of safety of 1.5, which meets the global stability minimum factor of safety requirement of 1.5. We understand the GEC Project No. 3506G 8 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

13 Fodderstack Slough Structure improvements (levees and sheet pile walls) are being designed by AECOM to prevent failures due to seepage and other hydraulic elements. 7.2 Sheet Pile Analysis We understand an approximately 600 foot long steel sheet pile wall will be constructed across the Fodderstack Slough as part of the weir and abutment structures. GEC analyzed the proposed weir and abutment steel sheet piles as detailed in the plans provided to us using the computer program CWALSHT. Our sheet pile wall analyses were conducted using the geometry provided to us in the plans and the results of our field and laboratory exploration program. The computer program, CWALSHT, was used to calculate minimum tip embedments, maximum sheet pile wall moments and scaled deflections. These analyses were initially conducted using a factor of safety of 1.5 on passive pressures to determine pile penetration. The analyses were then run again using a factor of safety of 1.0 on passive pressures to determine maximum moment and deflection in the pile. Our results indicated that the sheet pile walls should be tipped at elevations sheet pile walls should be tipped at elevations +26 ft NAVD88 (abutments) and +34 ft NAVD88 (weir) +26 ft NAVD88 (abutments) and +34 ft NAVD88 (weir) for total pile lengths of approximately 34 ft (abutments) and 24.3 ft (weir). Based on our analyses, we recommend a PZ35 sheet pile section for the abutments and a PZ22 sheet pile section for the weir. Our recommendations for the steel sheet piles are included on the Cantilever Steel Sheet Pile Data Table in the Appendix. The CWALSHT analyses results are also included the Appendix. 7.3 Control Structure Foundations On the basis of the data obtained for this study, the site is suitable for support of the proposed control structure upon a monolithic slab with thickened edges as shown in the project plans. 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. This includes removing and replacing any organic soils, including the organic soils encountered in borings B-3 and B-4, within 5 feet horizontally of any structure foundations. GEC Project No. 3506G 9 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

14 Prepare footing subgrade soils in accordance with the recommendations presented in the Foundation Subgrade Preparation section of this report. Use a maximum net soil bearing pressure of 2,500 pounds per square foot in footing/monolithic slab design. Use a maximum net soil bearing pressure of 2,500 pounds per square foot in footing/monolithic slab design. Design monolithic slabs so that the bottom of thickened slab sections bear at least 12 inches below the adjacent finished exterior grade. Support 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 analysis indicates that control structure foundations designed and constructed in accordance with the above recommendations will experience total settlements of less than about 1 inch and differential settlements between footings less than about ½ inch. The majority of this settlement is anticipated to occur during construction. 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. GEC Project No. 3506G 10 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

15 8.1 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. 8.2 General Site Preparation Our recommendations regarding routine site preparation of the fill and structure areas can be summarized as follows: Remove all vegetation and organic topsoil, major root systems and other deleterious materials from beneath and to a minimum of 5 feet beyond the proposed structure limits for the cut sections of the site or when no fill is required. For areas where fill is required to achieve final grade, such as the levee embankments, deleterious materials need to be removed from beneath and to 10 feet beyond the toe of the fill slope. Standard clearing, grubbing, and topsoil stripping procedures should be appropriate for 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. In structure 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. GEC Project No. 3506G 11 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

16 Proofroll the structure 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 and soil supported floor slabs. 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. These PT soils should be removed A layer of very soft sandy muck (PT) was from all structure and fill areas encountered at borings B-3and B-4 from existing ground surface to depths of 4 feet and 2 feet, respectively. Also, borings B-1, B-2 and B-5 encountered about 6 inches of organic topsoil. These PT soils should be removed from all structure and fill areas to a minimum of 10 feet beyond the proposed structure and levee areas. Silty sands (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. 3506G 12 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

17 8.3 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 3% 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 sands. 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 5 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. All excavations should comply with the recommendations included in the Temporary Excavations section of this report. 8.4 Shallow Foundation Subgrade Preparation We recommend the following steps be taken during slab/footing excavation and subgrade preparation: GEC Project No. 3506G 13 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

18 Excavate slab/footing in accordance with the recommendations presented in the Temporary Excavations section of this report. Compact slab/footing subgrade soils to a depth of 12 inches below 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 bearing elevation to verify slab/footing subgrade density. Allow a Geotechnical Engineer, or his representative, to observe 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 excavations and replace with sand selected and compacted in accordance with the Fill Selection, Placement and Compaction section of this report. 8.5 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. We anticipate that OSHA will classify these materials as Type C. 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 GEC Project No. 3506G 14 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

19 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. 9.0 QUALITY ASSURANCE We recommend establishing a comprehensive quality assurance program to verify that all site preparation and foundation, pavement and pond construction is conducted in accordance with the appropriate plans and specifications. Materials testing and inspection services should be provided by Geotechnical and Environmental Consultants, Inc. due to our familiarity with the site conditions and the intent of our recommendations. As a minimum, an on-site engineering technician should monitor all stripping and grubbing to verify that all deleterious materials have been removed. In-situ density tests should be conducted during earthwork activities and below all slabs to verify that the required densities have been achieved. In-situ density values should be compared to laboratory Proctor moisture-density results for each of the different natural and fill soils encountered. Finally, we recommend inspecting and testing the construction materials for the foundations and other structural components USE OF THIS REPORT GEC has prepared this report for the exclusive use of our client, AECOM, 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 evaluated the site for the potential presence of contaminated soil or groundwater, nor have we 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. GEC Project No. 3506G 15 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

20 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. 3506G 16 Report of Geotechnical Engineering Investigation Fodderstack Slough Improvements

30 Table 3 Summary of Laboratory Test Results FODDERSTACK SLOUGH IMPROVEMENTS GEC Project No. 3506G 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. B SP B SP-SM B SC B CL B SC B SP B SP-SM B SC B PT B SP B SM B PT B SP B SP-SM B SM B SP B SP B SP-SM B SP-SM B SP-SM B SP-SM

32 Table 4 Summary of Corrosion Series Test Results FODDERSTACK SLOUGH IMPROVEMENTS GEC Project No. 3506G Sample Minimum Boring Unified Soil Chlorides Sulfates Substructural Environmental Classification Depth ph Resistivity No. Classification (ppm) (ppm) (feet) (ohm-cm) Concrete Steel B-2 SP , < 5 Moderately Aggressive Extremely Aggressive B-3 Water , < 5 Moderately Aggressive Extremely Aggressive B-5 SP , Slightly Aggressive Moderately Aggressive

50 Cantilever Steel Sheet Pile Data Table FODDERSTACK SLOUGH IMPROVEMENTS GEC Project No. 3506G Sheetpile Wall Name * Minimum Wall Tip Elevation (ft NAVD88) ** A-328 (fy = 39 ksi) ** A-572 (f y = 50 ksi) Abutment , x PZ35 Weir , x PZ22 Notes: *In accordance with Section Minimum Section Modulus Construction Information**** **Allowable Design stress. Based on 65% of the yield stress (f y ). Maximum Allowable Bending Moment (ft-lbs) Minimum Required Moment of Inertia (in 4 ) *** Maximum Scaled Deflection (in 3 -lbs) Wall Top Elevation (ft NAVD88) Front of Wall (ft) Design Parameters**** Soil Elevation ***Divide maximum scaled deflection by Modulus of Elasticity (in 2 -lbs) times the moment of inertia (in 4 ) to obtain deflection in inches. Back of Wall (ft) Water Elevation Front of Wall (ft) Back of Wall (ft) Design Live Load (psf) Recommended Sheetpile Section ****The design parameters indicated in this table were used in the sheet pile wall analysis. If the Contractor's operations exceed the design parameters show above, it will be the Contractor's repsonsibility to redesign and construct the walls accordingly. A safety factor of 1.5 was applied to the passive and 1.0 applied to the active soil pressures to evaluate sheetpile embedment. For evaluation of the sheetpile section geometry, a safety factor of 1.0 was applied to both the passive and the active soil pressures. The sheet pile analysis and section properties are per foot of wall.