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Home My WebLink AboutGEOTECHNICAL REPORTr GFA INTERNATIONAL FLORIDA'S LEADING ENGINEERING SOURCE Report of Geotechnical Exploration Proposed One -Story Commercial Building Industrial Ave 3 St. Lucie County, Florida SCANNED August 24, 2017 13Y GFA Project No.: 17-5667.00 St. Lucie County For: EDC, Inc. ...........viYA 0111 ................ : o,.o.......,.. " tRN RECEIVED APR - 3 2018 mitting Department aELucieeCounty, FL . 40 �e °moo F LL ��Opy r ' 1 I Florida's Leading Engineering Source Environmental • Geotechnical • Construction Materials Testing • Threshold and Special Inspections • Plan Review & Code Compliance August 24, 2017 EDC, Inc. Attention: Jayson Harrison 10250 SW Village Parkway, Ste 201 Port St. Lucie, FL 34987 Site: Proposed One -Story Commercial Building Industrial Ave 3 St. Lucie County, Florida GFA Project # 17-5667.00 Dear Mr. Harrison: GFA International, Inc. (GFA) has completed the subsurface exploration and geotechnical engineering evaluation for the above -referenced project in accordance with the geotechnical and engineering service agreement for this project. The scope of services was completed in accordance with our Geotechnical Engineering Proposal (17-5667.00), planned in conjunction with and authorized by you. EXECUTIVE SUMMARY The purpose of our subsurface exploration was to classify the nature of the subsurface soils and general geomorphic conditions and evaluate their impact upon the proposed construction. This report contains the results of our subsurface exploration at the site and our engineering interpretations of these, with respect to the project characteristics described to us including providing recommendations for site preparation and the design of the foundation system. Based on a site plan (reproduced as the Test Location Plan) and conversations with the client, the project consists of constructing a one-story commercial building with a loading dock and associated parking. The building footprint would be on 29,900 square feet. The property does not have an address, and the parcels are identified as PCNs 1429-501-0116-000-4 and 1429- 501-0117-000-1 on the St. Lucie County Property Appraiser's website. We have not received any information regarding structural loads. For the foundation recommendations presented in this report we assumed the maximum column load will be 75 kips and the maximum wall loading will be 4 kips per linear foot. We estimate the site is at or near final grade. The recommendations provided herein are based upon the above considerations. If the project description has been revised, please inform GFA International so that we may review our recommendations with respect to any modifications. A total of five (5) standard penetration test (SPT) borings to depths of approximately fifteen (15) feet, and two (2) Auger Borings (AB) to approximately six (6) feet, below ground surface (BGS)_ were completed for this study. Hand Cone Penetrometer (HCP) tests were conducted at one - foot intervals in the auger borings. The HCP test, in conjunction with information about the soil type, is empirically correlated to the relative density of subsurface soils. The locations of the borings performed are illustrated in Appendix B: "Test Location Plan". 607 NW Commodity Cove- Port St. Lucie, Florida 34986 • (772) 924.3575 • (772) 924.3580 OFFICES THROUGHOUT , Proposed One -Story Commercial Building Industrial Ave 4, St. Lucie County, Florida GFA Project No. 17-5667.00 Geotechnical Report August 24, 2017 Page 2 of 15 The subsurface soil conditions encountered at the boring locations generally consist of very loose sand (SP) to a depth of 2 feet, loose to medium dense sand (SP) or silty sand (SP- SM,SM) to the boring termination depths. Please refer to Appendix D - Record of Test Borings for a detailed account of each boring. The subsurface soil conditions at the project site are generally favorable for the support of the proposed structure on shallow foundations. An allowable bearing capacity of 2,500 psf may be used for foundation design. The subgrade soils should be improved with compaction from the existing grade prior to constructing the foundation pads. The top 2 feet below existing grade should be compacted to a minimum of 95% density prior to placing fill to achieve final grade. Fill (including stemwall backfill) should be placed in 12-inch lifts and compacted to achieve a minimum 95% density. After excavation for footings, the subgrade to a depth of 2 feet below bottom of footings should be compacted to achieve a minimum 95% density. Silty and clayey soils were encountered in the borings which could pose footing bottom compaction problems. If compaction cannot be attained due to persistent wetness or the water table near the bottom of the footing excavation, or due to silty/clayey soil 'pumping' during compaction, GFA recommends undercutting below bottom of footing and replacement with No. 57 stone, or rock/sand fill for subgrade that cannot be compacted per recommendations (upper 2 feet, more if required to achieve stable subgrade). The rock/sand fill should be compacted and tamped into the excavation and inspected and verified by a representative from GFA, and tested with hand cone penetrometers, probe rods, or density tests We appreciate the opportunity to be of service to you on this project and look forward to a continued association. Please do not hesitate to contact us if you have any questions or comments, or if we may further assist you as your plans proceed. ..eeenee,,_ 10 ' • eitificate ofAuth,c"tion Number 4930 ze N .44I65,� !j, % TVbF r :fie }fo h, Paa.�. ,•��e^ i an Collie, E.I. e�ag @§�Yfe• °° o ct Manager lorid°� �� ,%$653 s0eree re1eee� Copies: 2, Addressee (I FA Proposed One -Story Commercial Building Geotechnica/ Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 3 of 15 TABLE OF CONTENTS GFA Project # 17-5667.00...............................................................................................1 1.0 INTRODUCTION......................................................................................................4 1.1 Scope of Services...................................................................................................4 1.2 Project Description.................................................................................................4 2.0 OBSERVATIONS......................................................................................................4 2.1 Site Inspection.......................................................................................................4 2.2 Field Exploration....................................................................................................5 2.3 Laboratory Analysis...............................................................................................5 3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS..................................6 3.1 General.................................................................................................................6 3.2 Site Preparation....................................................................................................7 3.3 Design of Footings................................................................................................8 3.4 Ground Floor Slabs...............................................................................................8 3.5 Lateral Earth Pressure Coefficients......................................................................9 3.6 Excavation Conditions..........................................................................................9 4.0 PARKING AND ROADWAY CONSTRUCTION RECOMMENDATIONS ............................10 4.1 General................................................................................................................10 4.2 Compacted Subgrade or Embankment Fill..........................................................11 4.3 Stabilized Subgrade.............................................................................................11 4.4 Base Course........................................................................................................11 4.5 Surface Course....................................................................................................12 4.6 Concrete Pavement.............................................................................................12 4.7 Effects of Water...................................................................................................12 4.8 Construction Traffic..............................................................................................13 4.9 Pavement Site Preparation..................................................................................13 5.0 REPORT LIMITATIONS.........................................................................................14 6.0 BASIS FOR RECOMMENDATIONS..................................................................................14 Appendix A— Vicinity Map Appendix B — Test Location Plan Appendix C — Notes Related to Test Borings Appendix D — Record of Test Borings Appendix E — Discussions of Soil Groups GFA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 4 of 15 1.0 INTRODUCTION 1.1 Scope of Services The objective of our geotechnical services was to collect subsurface data for the subject project, summarize the test results, and discuss any apparent site conditions that may have geotechnical significance for building construction. The following scope of services is provided within this report: Prepare records of the soil boring logs depicting the subsurface soil conditions encountered during our field exploration. 2. Conduct a review of each soil sample obtained during our field exploration for classification and additional testing if necessary. 3. Analyze the existing soil conditions found during our exploration with respect to foundation support for the proposed structure. 4. Provide recommendations with respect to foundation support of the structure, including allowable soil -bearing capacity, bearing elevations, and foundation design parameters. 5. Provide criteria and site preparation procedures to prepare the site for the proposed construction. 1.2 Project Description Based on a site plan (reproduced as the Test Location Plan) and conversations with the client, the project consists of constructing a one-story commercial building with a loading dock and associated parking. The building footprint would be on 29,900 square feet. The property does not have an address, and the parcels are identified as PCNs 1429-501-0116-000-4 and 1429- 501-0117-000-1 on the St. Lucie County Property Appraiser's website. We have not received any information regarding structural loads. For the foundation recommendations presented in this report we assumed the maximum column load will be 75 kips and the maximum wall loading will be 4 kips per linear foot. We estimate the site is at or near final grade. The recommendations provided herein are based upon the above considerations. If the project description has been revised, please inform GFA International so that we may review our recommendations with respect to any modifications. 2.0 OBSERVATIONS 2.1 Site Inspection The project site was generally flat and grassy with trees. The grade at the site was estimated to be 3 feet above the adjacent road at the time of drilling. The site was not occupied at the time of drilling. Commercial structures were adjacent to the property. 6FA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 5 of 15 2.2 Field Exploration A total of five (5) standard penetration test (SPT) borings to depths of approximately fifteen (15) feet, and two (2) Auger Borings (AB) to approximately six (6) feet, below ground surface (BGS) were completed for this study. Hand Cone Penetrometer (HCP) tests were conducted at one - foot intervals in the auger borings. The HCP test, in conjunction with information about the soil type, is empirically correlated to the relative density of subsurface soils. The locations of the borings performed are illustrated in Appendix B: 'Test Location Plan". The Standard Penetration Test (SPT) and HCP methods were used as the investigative tools within the borings. SPT tests were performed in substantial accordance with ASTM Procedure D-1586, "Penetration Test and Split -Barrel Sampling of Soils" and the auger borings in substantial accordance with ASTM Procedure D-1452, "Practice for Soil Investigation and Sampling by Auger Borings". The SPT test procedure consists of driving a 1.4-inch I.D. split -tube sampler into the soil profile using a 140-pound hammer falling 30 inches. The number of blows per foot, for the second and third 6-inch increment, is an indication of soil strength. The soil samples recovered from the soil borings were visually classified and their stratification is illustrated in Appendix D: 'Record of Test Borings". It should be noted that soil conditions might vary between the strata interfaces, which are shown. The soil boring data reflect information from a specific test location only. Site specific survey staking for the test locations was not provided for our field exploration. The indicated depth and location of each test was approximated based upon existing grade and estimated distances and relationships to obvious landmarks. The boring depths were confined to the zone of soil likely to be stressed by the proposed construction and knowledge of vicinity soils. 2.3 Laboratory Analysis Soil samples recovered from our field exploration were returned to our laboratory where they were visually examined in general accordance with ASTM D-2488. Samples were evaluated to obtain an accurate understanding of the soil properties and site geomorphic conditions. Laboratory tests were performed on selected samples for soil classification purposes. The samples were tested for moisture content (ASTM D 2216), gradation sieve analysis for clay/silt content determination (ASTM D 422), and organic content (ASTM D 2974). The moisture contents ranged from 3.2 to 35.7 percent and the silt/clay content passing the No. 200 sieve ranged from 2.7 to 8.7 percent. The test results are shown on the boring logs. The recovered samples were not examined, either visually or analytically, for chemical composition or environmental hazards. GFA would be pleased to perform these services for an additional fee, if required. 2.4 Geomorphic Conditions The geology of the site as mapped on the USDA Soil Survey website consists of Lawnwood and Myakka sand (21). These are sandy soils and organic soils are not indicated. It should be noted that the Soil Survey generally extends to a maximum depth of 80 inches (approximately 63/< feet) below ground surface and is not indicative of deeper soil conditions. Boring logs derived from our field exploration are presented in Appendix D: 'Record of Test Borings". The boring logs depict the observed soils in graphic detail. The Standard Penetration GFA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 6 of 15 Test borings indicate the penetration resistance, or N-values, and the auger borings the HCP values logged, during the drilling and sampling activities. The classifications and descriptions shown on the logs are generally based upon visual characterizations of the recovered soil samples. All soil samples reviewed have been depicted and classified in general accordance with the Unified Soil Classification System, modified as necessary to describe typical Florida conditions. See Appendix E: "Discussion of Soil Groups", for a detailed description of various soil groups. The subsurface soil conditions encountered at the boring locations generally consist of very loose sand (SP) to a depth of 2 feet, loose to medium dense sand (SP) or silty sand (SP- SM,SM) to the boring termination depths. Please refer to Appendix D - Record of Test Borings for a detailed account of each boring. 2.5 Hydrogeological Conditions On the dates of our field exploration, the groundwater table was encountered at depths ranging from approximately 3% to 5 feet below the existing ground surface. The groundwater table will fluctuate seasonally depending upon local rainfall and other site specific and/or local influences. Brief ponding of stormwater may occur across the site after heavy rains. No additional investigation was included in our scope of work in relation to the wet seasonal high groundwater table or any existing well fields in the vicinity. Well fields may influence water table levels and cause significant fluctuations. If a more comprehensive water table analysis is necessary, please contact our office for additional guidance. 3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS 3.1 General A foundation system for any structure must be designed to resist bearing capacity failures, have settlements that are tolerable, and resist the environmental forces that the foundation may be subjected to over the life of the structure. The soil bearing capacity is the soil's ability to support loads without plunging into the soil profile. Bearing capacity failures are analogous to shear failures in structural design and are usually sudden and catastrophic. The amount of settlement that a structure may tolerate is dependent on several factors including: uniformity of settlement, time rate of settlement, structural dimensions and properties of the materials. Generally, total or uniform settlement does not damage a structure but may affect drainage and utility connections. These can generally tolerate movements of several inches for building construction. In contrast, differential settlement affects a structure's frame and is limited by the structural flexibility. The subsurface soil conditions at the project site are generally favorable for the support of the proposed structure on shallow foundations. An allowable bearing capacity of 2,500 psf may be used for foundation design. Expected settlement of the structure is 1 inch or less total and less than %2 inch differential. 6FA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 7 of 15 3.2 Site Preparation GFA recommends the following compaction requirements for this project: ➢ Proof Roll .................. ➢ Building Pad Fill ........ ➢ Footings .................... 95% of a Modified Proctor 95% of a Modified Proctor 95% of a Modified Proctor The compaction percentages presented above are based upon the maximum dry density as determined by a "modified proctor' test (ASTM D-1557). All density tests should be performed to a depth of 2 feet below stripped surface and below bottom of footings. Or All density tests should be performed using the nuclear method (ASTM D-2922), the sand cone method (ASTM D-1556), or Hand Cone Penetrometer (HCP) tests. Our recommendations for preparation of the site for use of shallow foundation systems are presented below. This approach to improving and maintaining the site soils has been found to be successful on projects with similar soil conditions. Initial site preparation should consist of performing stripping (removing surface vegetation, near surface roots, and other deleterious matter) and clearing operations. This should be done within, and to a distance of five (5) feet beyond, the perimeter of the proposed building footprint (including exterior isolated columns). Foundations and any below grade remains of any structures that are within the footprint of the new construction should be removed, and utility lines should be removed or properly abandoned so as to not affect structures. Following site stripping and prior the placement of any fill, areas of surficial sand (not exposed limestone) should be compacted ("proof rolled") and tested. We recommend using a steel drum vibratory roller with sufficient static weight and vibratory impact energy to achieve the required compaction. If the subgrade is too wet or the inflow of groundwater cannot be controlled so that the compaction is not achievable, then very clean granular fill may be placed up to 1 foot above the water table, intensively densified and compacted until no further settlement can be visually discerned at the fill surface, and 1 foot of soil both above and below the water table have achieved at least 95% density. Density tests should be performed on the proof rolled surface at a frequency of not less than one test per 2,500 square feet, or a minimum of three (3) tests, whichever is greater. Areas of exposed intact limestone shall be visually confirmed by the project geotechnical engineer prior to fill placement, in lieu of proof rolling. 3. Fill material may then be placed in the building pad as required. The fill material should be inorganic (classified as SP, SW, GP, GW, SP-SM, SW-SM, GW-GP, GP -GM) containing not more than 5 percent (by weight) organic materials. Fill materials with silt/clay-size soil fines in excess of 12% should not be used. Fill should be placed in lifts with a maximum lift thickness not exceeding 12-inches. Each lift should be compacted and tested prior to the placement of the next lift. Density tests should be performed within the fill at a frequency of not less than one test per 2,500 square feet per lift in the building areas, or a minimum of three (3) tests per lift, whichever is greater. 6FA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 8 of 15 4. For any footings bearing on a limestone formation, the bottom of all footing excavation shall be examined by the engineer / geologist or his representative to determine the condition of the limestone. The limestone shall be probed for voids and loose pockets of sand. Such areas shall be cleaned to depth of 3 times the greatest horizontal dimension and backfilled with lean concrete. 5. For footings placed on structural fill or compacted native granular soils, the bottom of all footings shall be tested for compaction and examined by the engineer / geologist or his representative to determine if the soil is free of organic and/or deleterious material. Density tests should be performed at a frequency of not less than one (1) density test per each isolated column footing and one (1) test per each seventy five (75) lineal feet of wall footings. If compaction cannot be attained due to persistent wetness or the water table near the bottom of the footing excavation, or due to silty/clayey soil 'pumping' during compaction, GFA recommends undercutting below bottom of footing and replacement with No. 57 stone, or rock/sand fill for subgrade that cannot be compacted. The rock/sand fill should be compacted and tamped into the excavation and inspected and verified by a representative from GFA, and tested with hand cone penetrometers, probe rods, or density tests. 6. The contractor should take into account the final contours and grades as established by the plan when executing his backfilling and compaction operations. Using vibratory compaction equipment at this site may disturb adjacent structures. We recommend that you monitor nearby structures before and during proof -compaction operations. A representative of GFA International can monitor the vibration disturbance of adjacent structures. A proposal for vibration monitoring during compaction operations can be supplied upon request. 3.3 Design of Footings Footings may be designed using an allowable soil bearing pressure of 2,500 psf. Shallow foundations should be embedded a minimum of 12 inches below final grade. This embedment shall be measured from the lowest adjacent grade. Isolated column footings should be at least 24 inches in width and continuous strip footings should have a width of at least 16 inches regardless of contact pressure. Once site preparation has been performed in accordance with the recommendations described in this report, the soil should readily support the proposed structure resting on a shallow foundation system. Settlements have been projected to be less than 1-inch total and %:-inch differential. All footings and columns should be structurally separated from the floor slab, as they will be loaded differently and at different times, unless a monolithic mat foundation is designed. 3.4 Ground Floor Slabs The ground floor slabs may be supported directly on the existing grade or on granular fill following the foundation site preparation and fill placement procedures outlined in this report. For purposes of design, a coefficient of subgrade modulus 150 pounds per cubic inch may be (1 FA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 9 of 15 used. The ground floor slab should be structurally separated from all walls and columns to allow for differential vertical movement unless a monolithic foundation is used. Excessive moisture vapor transmission through floor floor coverings as well as cause other deleterious retarder should be placed beneath the floor slab to building through the slab. The retarder should t applicable ASTM procedures including sealing arow foundations. 3.5 Lateral Earth Pressure Coefficients slabs -on -grade can result in damage to affects. An appropriate moisture vapor reduce moisture vapor from entering the e installed in general accordance with Id pipe penetrations and at the edges of GFA recommends that cantilever retaining walls for truck docks be designed to resist the "active" earth pressure. Where the top of the retaining wall and the junctions between the two retaining walls is restrained against movement, we recommend that "at rest" earth pressure should be used for design. The recommended soil parameters for the design of the retaining walls are presented in the table below. Additional wall loading from forklifts and food/grocery goods stockpiled near the wall should be accounted for in the design. DESIGN COEFFICIENTS Design Parameter Recommended Value Soil Friction Angle (0) (deg) 30 At -rest Earth Pressure Coefficiemt K. 0.50 Active Earth Pressure Coefficiemt K, 0.33 Passive Earth Pressure Coefficiemt Kp 3.0 Hydrostatic Pressure for Design V. 62.4 Coefficient of Wall Friction Between Concrete and In -situ Soils 0.35 Modulus of Subgrade Reaction K, 150 pci Dry Unit Weight of Soil yd 105 pcf Wet Unit Weight of Soil y„,,t 110 pcf Effective Unit Weight of Soil y,ff 48 pcf The earth coefficients presented above assume the retaining walls would be backfilled with clean granular soils. Where the potential exists for buildup of hydrostatic pressure due to the water table, hydrostatic pressure should be assumed and added to the earth pressure for design, unless drainage is provided behind the retaining wall. 3.6 Excavation Conditions In Federal Register, Volume 54, No. 209 (October 1989), the United States Department of Labor, Occupational Safety and Health Administration (OSHA) amended its "Construction Standards for Excavations, 29 CFR, part 1926, Subpart P". This document was issued to better insure the safety of workmen entering trenches or excavations. It is mandated by this federal Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 10 of 15 regulation that all excavations, whether they be utility trenches, basement excavations or footing excavations, be constructed in accordance with the OSHA guidelines. The contractor is solely responsible for designing and constructing stable, temporary excavations and should shore, slope, or bench the sides of any excavations deeper than 4 feet as required to maintain stability of both the excavation sides and bottom. The contractor's responsible person, as defined in 29 CFR Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety procedures. In no case should slope height, slope inclination, or excavation depth, including utility trench excavation depth, exceed those specified in local, state, and federal safety regulations. GFA is providing this information solely as a service to our client. GFA is not assuming responsibility for construction site safety or the contractor's activities; such responsibility is not being implied and should not be inferred. 4.0 PARKING AND ROADWAY CONSTRUCTION RECOMMENDATIONS 4.1 General Projected traffic loadings were unavailable at the time of this report. Flexible pavement structures in this geographic area typically consist of an asphaltic wearing course, a base course, and a stabilized subgrade. As an option, concrete pavements can also be utilized and constructed directly on top of prepared grades or on top of a base course and stabilized subgrade for heavier loads. Based on our experience in the area and the anticipated traffic weights, the typical pavement section thicknesses are provided in Table F below: Table F: Typical Pavement Section Recommendations Type of Layer Material Description Layer Thickness Light Duty Heavy Duty Pavement Flexible (A) FDOT Type S (non FDOT) or SP 1.5 2.5 FDOT (B) Crushed Base with minimum LBR 6 8 OF 100, compacted to 98% of the modified Proctor maximum dry density (SSG) Stabilized sub -grade fill (LBR 40), 12 12 compacted to 98% of the modified Proctor maximum dry density STRUCTURAL NUMBER SN 2.7 3.5 Rigid (C) Florida DOT Portland Cement NA 8 Concrete (B) Crushed Limerock with minimum NA - LBR OF 100, compacted to 98% of the modified Proctor maximum dry density (CSG) Compacted sub -grade fill, NA 12 compacted to 98% of the modified Proctor maximum dry density GFA Proppsed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 11 of 15 Parking lots — light duty: auto parking areas; light panel and pickup trucks; 10,000 18-kip equivalent axle loads for a 20 year design life Parking lots — heavy duty: shopping center driveways; delivery vehicles and semi -trucks; 50,000 18-kip equivalent axle loads for a 20 year design life 4.2 Compacted Subgrade or Embankment Fill The subgrade or embankment fill is the layer that supports the structural pavement section. Subgrade and embankment fill should be compacted and in compliance to specifications presented later in the pavement site preparation procedure section of this report. 4.3 Stabilized Subgrade The stabilized subgrade is the portion of the pavement section between the compacted subgrade or embankment fill and the base course. We recommend subgrade material be compacted to 98 percent of the Modified Proctor maximum dry density value (AASHTO T-180). The subgrade material should be stabilized to a minimum Limerock Bearing Ratio (LBR) of 40. As an alternative, the pavement section can be designed using the natural sand and consequently a lower LBR value. If this is desired, an LBR test of the natural sands should be performed and incorporated into a modified pavement design. Perform compliance tests on the stabilized subgrade for full depth at a frequency of one test per 5,000 square feet, or at a minimum of two test locations, whichever is greater. 4.4 Base Course The base course is the portion of the pavement section between the surface course and stabilized subgrade. In areas where separation of at least 1'/z feet between the estimated wet seasonal high groundwater table and the bottom of the base material occurs, we recommend the base course be limerock minimum (LBR=100). Limerock material should be mined from an approved source. The limerock should be placed in lifts no greater than 6-inches and compacted to at least 98 percent of the Modified Proctor maximum dry density value (AASHTO T-180). If separation between the estimated wet seasonal high groundwater table and the bottom of the base material is less than 1'h feet, we recommend that crushed limerock not be used. The base course should be of an asphaltic base (ABC-3 with a minimum Marshall Stability of 1,000 pounds). In addition, to minimize the potential for perching of the groundwater table, we do not recommend the use of chemically stabilized subgrade (i.e. sludge). Instead, the subgrade should be mechanically stabilized (compacted) to a minimum of 98 percent of the soil's Modified Proctor maximum dry density value (AASHTO T-180). Perform compliance tests on the base course to its respective depth (6" or 8") at a frequency of one test per 5,000 square feet, or a minimum of two test locations, whichever is greater. 6FA Proposed One -Story Com me cial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 12 of 15 4.5 Surface Course The surface course is usually the portion of the pavement section, which is exposed directly to traffic. In the light duty areas where there is occasional truck traffic, but predominantly passenger cars, we recommend using asphaltic concrete, which has a stability of 1,500 pounds. Heavy-duty areas where truck traffic is predominant, we recommend using asphaltic concrete, which has a minimum stability of 1,500 pounds. Asphaltic concrete mixes shall consist of the materials actually used and should concur to a current approved design. Samples of the materials delivered to the project should be tested to verify that the aggregate gradation and asphalt content satisfies the mix design specifications. Asphalt should be compacted to a minimum of 95 percent of the laboratory density. Perform compliance tests on the surface course, by coring to evaluate the material thickness and to perform laboratory densities, at a frequency of one test per 10,000 square feet, or a minimum of two test locations, whichever is greater. 4.6 Concrete Pavement The minimum rigid pavement thickness recommended in this report is based upon concrete with a minimum compressive strength of 4,000 psi. Fill that may be required to raise grades in slab areas should be compacted to at least 98 percent of the Modified Proctor maximum dry density (ASTM D-1557). The pavement slabs should be reinforced to make them as rigid a practical. Proper joints should be provided at the junctions of slabs and foundation systems so that a small amount of independent movement can without causing structural damage. Construction and control joints should be accordance with ACI and Industry practices. Actual pavement section thickness should be provided by the Design Civil Engineer based on traffic loads, volume, and the owner's design life requirements. The above section represents the minimum thickness representative of typical local construction procedures and, as such, periodic maintenance should be anticipated. All pavement materials and construction procedures should conform to the FDOT, American Concrete Institute (ACI), or appropriate city/county requirements. 4.7 Effects of Water Many roadways and parking areas have prematurely deteriorated due to intrusion of the wet seasonal high groundwater table or surface runoff mitigation. We recommend the roadways and parking areas be constructed with a minimum separation of 1'/2 feet between the wet seasonal high groundwater table and the base course, independent of the type of base material used. In addition, the parking areas should be constructed with full - depth curb sections. Using extruded curb sections, which lie directly on top of the final surface course or eliminating the curbing entirely, may allow migration of runoff and/or irrigation water to migrate between the base and surface course. This migration can result in separation of the surface course from the base course causing a rippling effect, which result in an increase deterioration of the pavement. (I FA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 13 of 15 4.8 Construction Traffic Incomplete pavement sections or areas of pavement designed for light duty traffic will not perform satisfactory under construction traffic loadings. We recommend all construction traffic (i.e. construction equipment, etc.) be re-routed away from these areas or the pavement sections be design to support these loading conditions. 4.9 Pavement Site Preparation Upon review of the site soil data, our recommendations for preparation of the site for pavements are noted below. This approach to improving and maintaining the site soils has been found to be successful with very similar soil conditions. Initial site preparation should consist of performing dewatering operations if necessary prior to any earthwork. 2. The proposed construction limits should be cleared, stripped and grubbed of all construction debris and the existing vegetation and associated root systems to a depth of their vertical reach. This should be done within and to a distance of 5 feet beyond the road perimeter. 3. Prior to any fill operations, the existing ground surface should be compacted. We recommend a medium weight roller be used to prepare the site for the proposed pavement section. Upon completion of the proof -rolling, density tests should be performed at a frequency of one test per 5,000 square feet, or at a minimum of two test locations, whichever is greater, to confirm a minimum compaction compliance of 98 percent of modified proctor maximum density (AASHTO T-180). Should roadway subgrade soils become loose due to groundwater seepage or excessive storm rain runoff the contractor may choose to stabilize this condition by replacing the wet soils with No. 57 stone or equivalent backfill. The Geotechnical Engineer should inspect this improvement prior to construction of the remaining pavement section. 4. Place fill material, as required. The fill material should be inorganic (classified as SP/GW) containing not more than 5 percent (by weight) fibrous organic materials. Fill materials with silt -size soil fines in excess of 5% should not be used, this includes cyclone sand material. Place fill in maximum 12-inch lifts and compact each lift to a minimum density of 98 percent of the Modified Proctor maximum dry density (AASHTO T-180) with a roller as mentioned previously. . 5. Perform compliance tests within the fill at a frequency of not less than one test per 5,000 square feet per lift in the pavement areas, or at a minimum of two test locations, whichever is greater. 6. The appropriate pavement section should be constructed in accordance to specification present earlier in this report. 7. Representative samples of the on -site material and proposed fill material should be collected and tested to determine the classification and compaction characteristics 6FA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 14 of 15 (AASHTO T-180). The maximum dry density, optimum moisture content, and gradation characteristics should be determined. 8. The contractor shall take into account the final contours and grades as established by the paving and drainage plan when executing any backfilling and / or compaction operations. Using vibratory compaction equipment at this site may disturb adjacent structures. We recommend that you monitor nearby structures before and during proof -compaction operations. If disturbance is noted, halt vibratory compaction operations and inform GFA immediately. We will review the compaction procedures and evaluate if the compactive effort resulted in a satisfactory subgrade, complying with design specifications. 5.0 REPORT LIMITATIONS This consulting report has been prepared for the exclusive use of the current project owners and other members of the design team for the Proposed Commercial Building located at Industrial Ave 3 in St. Lucie County, Florida. This report has been prepared in accordance with generally accepted local geotechnical engineering practices; no other warranty is expressed or implied. The evaluation submitted in this report, is based in part upon the data collected during a field exploration, however, the nature and extent of variations throughout the subsurface profile may not become evident until the time of construction. If variations then appear evident, it may be necessary to reevaluate information and professional opinions as provided in this report. In the event changes are made in the nature, design, or locations of the proposed structure, the evaluation and opinions contained in this report shall not be considered valid, unless the changes are reviewed and conclusions modified or verified in writing by GFA International. GFA should be provided the opportunity to review the final foundation specifications and review foundation design drawings, in order to determine whether GFA's recommendations have been properly interpreted, communicated and implemented. If GFA is not afforded the opportunity to participate in construction related aspects of foundation installation as recommended in this report or any report addendum, GFA will accept no responsibility for the interpretation of our recommendations made in this report or on a report addendum for foundation performance. 6.0 BASIS FOR RECOMMENDATIONS The analysis and recommendations submitted in this report are based on the data obtained from the tests performed at the locations indicated on the attached figure in Appendix B. This report does not reflect any variations, which may occur between borings. While the borings are representative of the subsurface conditions at their respective locations and for their vertical reaches, local variations characteristic of the subsurface soils of the region are anticipated and may be encountered. The delineation between soil types shown on the soil logs is approximate and the description represents our interpretation of the subsurface conditions at the designated boring locations on the particular date drilled. Any third party reliance of our geotechnical report or parts thereof is strictly prohibited without the expressed written consent of GFA International. The applicable SPT methodology (ASTM D-1586), CPT methodology (ASTM D-3441), and Auger Boring methodology (ASTM D-1452) 6FA Proposed One -Story Commercial Building Industrial Ave 4, St. Lucie County, Florida GFA Project No. 17-5667.00 used in performing our borings an Geotechnical Report August 24, 2017 Page 15 of 15 d GFA 1 Appendix A - Vicinity Map GfH Vicinity Map Industrial Ave 3 Fort Pierce, FL GFA Project No. 17-5667.00 r a n , • r - aj _� io y " T � - 1 L -tt fail p� r Appendix B - Test Location Plan GFP Test Location Plan: Industrial Ave 3, Fort Pierce, FL ',�� eld�M•e1p0� • v.,�,�, _ C'. w^r wem �_�� • ' 'st I I Jl e � _ �_ L!Y.' ...ems.. ..eas �•. I I -Approximate Standard Penetration Test (SPT) Boring & Auger Boring (AB) Locations Appendix C - Notes Related to Borings GfP NOTES RELATED TO RECORDS OF TEST BORING AND GENERALIZED SUBSURFACE PROFILE 1. Groundwater level was encountered and recorded (if shown) following the completion of the soil test boring on the date indicated. Fluctuations in groundwater levels are common; consult report text for a discussion. 2. The boring location was identified in the field by offsetting from existing reference marks and using a cloth tape and survey wheel. 3. The borehole was backfilled to site grade following boring completion, and patched with asphalt cold patch mix when pavement was encountered. 4. The Record of Test Boring represents our interpretation of field conditions based on engineering examination of the soil samples. 5. The Record of Test Boring is subject to the limitations, conclusions and recommendations presented in the Report text. 6. "Field Test Data' shown on the Record of Test Boring indicated as 11/6 refers to the Standard Penetration Test (SPT) and means 11 hammer blows drove the sampler 6 inches. SPT uses a 140-pound hammer falling 30 inches. 7. The N-value from the SPT is the sum of the hammer blows required to drive the sampler the second and third 6- inch increments. 8. The soil/rock strata interfaces shown on the Records of Test Boring are approximate and may vary from those shown. The soillrock conditions shown on the Records of Test Boring refer to conditions at the specific location tested; soil/rock conditions may vary between test locations. 9. Relative density for sands/gravels and consistency for silts/clays are described as follows: SPT CPT SANDS/GRAVELS SPT CPT SILTS/CLAYS BLOWS/FOOT KG1CM- RELATIVE DENSITY BLOWS/FOOT KG/CM- CONSISTENCY 04 0-16 Very loose 0-1 0-3 Ve soft 5-10 17-40 Loose 24 4-6 Soft 11-30 41-120 Medium Dense 5-8 7-12 Firm 31-50 121-200 Dense 9-15 13-25 Stiff 50+ over 200 Very Dense 16-30 25-50 Very stiff >30 >50 Hard 10. Grain size descriptions are m follows: NAME SIZE LIMITS Boulder 12 Inches or more Cobbles 3 to 12Inches Coarse Gravel Y to 3 Inches Fine Gravel No. 4 sieve to % inch Coarse Sand No. 10 to No. 4 sieve Medium Sand No. 40 to No. 10 sieve Fine Sand No. 200 to No. 40 sieve Fines I Smaller than No. 200 sieve 11. Definitions related to adjectives used in soil/rock descriptions: PROPORTION ADJECTIVE APPROXIMATE ROOT DIAMETER ADJECTIVE <5% Trace Less than 1/32" Fine roots 5%to 12% Little 1/32" to VV Small roots 12%to 30% Some W, to 1" Medium roots 30%to 50% And Greater than 1" Lareroots Organic Soils: Soils containing vegetable tissue in various stages of decomposition that has a fibrous to amorphous texture, usually a dark brown to black color, and an organic odor. Organic Content <25%: Slightly to Highly Organic; 25% to 75%: Muck;>75%: Peat GfP Appendix D - Record of Test Borings GfP GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. Luc1E. FLORIDA 34986 PHONE: (772)924-3575 - FAX:(772) 924-3580 I STANDARD PENETRATION TEST BORING (ASTM D-1586) I Client: EDC, Inc. Project: Industrial Ave 3 Fort Pierce, FL Elevation: Existing Grade Water Level: 3.8 feet after 0 hours Drilling Fluid commenced at depth of 10 feet Project No.:17-5667.00 Lab No.: Page: 1 of 1 Date: 8/14/2017 Drill Rig: CME45 Field Party: PM/MM TEST LOCATION: SPT - 1 N27.49394° W80.35147° Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. 200 Content Content 0 ......z................ 0 - 3% SP Light gray fine sand 1 .....4................. -- 8 12 1 2 .....8................. 6 3 .....2................. 10 19 2 3A - 5 SM Dark brown organically stained fine sand, 4 -12 12 some silt 5 ....R............... 5-6 SP Gray fine sand 6 16 3 6 ..... 1 ................. 6-10 SP Brown fine sand, trace silt 6 7 .....6................. 7 13 4 8 -- ...._6................. 6 7 9 ......7........14.. 5 10 .....9................. 12 ......................... 13 ......................... 14 4 13'/2 - 15 SP Gray fine sand 3.... --- 15 ..... 4..... ...-7.... 6 Boring Terminated at 15 feet 16 ......................... 17 ......................... 18 ......................... 19 ......................... GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LucIE. FLORIDA 34986 PHONE: (772) 924-3575 - FAX:(772) 924-3580 I STANDARD PENETRATION TEST BORING (ASTM D-1586) I Client: EDC, Inc. Project: Industrial Ave 3 Fort Pierce, FL Elevation: Existing Grade Water Level: 4 feet after 0 hours Drilling Fluid commenced at depth of 10 feet Project No.:17-5667.00 Lab No.: Page: 1 of 1 Date: 8/14/2017 Drill Rig: CME45 Field Party: PM/MM TEST LOCATION: SPT - 2 N27.49383° W80.35106° Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. 200 Content Content 3 0-5 SP Gray fine sand 1 ....-3................. 3 6 1 -- 2 .....4................. 3 3 .....3................. -- 6 9 2 4 ..... ................ 5 5 .....5................. 5-7 SM Brown fine sand, some silt --' 6 11 3 6 Z .... ..... 8 ............ 7 ..... 9..... .... -...... 7-10 SP Brown fine sand, trace silt 9 18 4 B....1.1 ................ 8 to - 10 20 5 10 ..... ........ ............ 11 1........................ 12 ......................... 13 ......................... 13%: - 15 SM Dark brown fine sand, some silt 14 .4 Z.... --- 15 .....2......... 5.... 6 Boring Terminated at 15 feet 16 ............ ............ 17 ......... ............... is......................... 19 ......................... r _i l � GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LUCIE. FLORIDA 34986 PHONE: (772) 924-3575 - FAX: (772) 924-3580 STANDARD PENETRATION TEST BORING (ASTM D-1586) Client: EDC, Inc. Project: Industrial Ave 3 Fort Pierce, FL Elevation: Existing Grade Water Level: 5 feet after 0 hours Drilling Fluid commenced at depth of 10 feet Project No.:17-5667.00 Lab No.: Page: 1 of 1 Date: 8/14/2017 Drill Rig: CME45 Field Party. PM/MM TEST LOCATION: SPT - 3 N27.49414° W80.35123° Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6in. Value No. From/to No. 200 Content Content SP Gray fine sand I. 1 ..... .... ............ 2 3 1 2 .....2................. 2 -- 2 3 ..... 4.... .....G_. 2 5 3% - 5 SM Dark brown organically stained fine sand, 4 7 some silt 5 ....10............... 10 20 3 5-7 SP-SM Brown fine sand, little silt 6 ....10............... 10 - 10 7-9 SP Brown fine sand 13 23 4 8 ....10................ 6 10 13 23 5 9-10 SP Brown fine sand, trace clay --- 10 10 .... ................ 12 ...... .................. 13 ......................... 2 13'/2 - 15 SP Gray fine sand, trace clay, trace shell 14 z.... 6 IS...._?........_4.... Boring Terminated at 15 feet 16 ..... ....... ............ 17 ......................... 18 ............. ..... ...... 19 ......................... GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LucIE. FLORIDA 34986 PHONE: (772) 924-3575 - FAx: (772) 924-3580 STANDARD PENETRATION TEST BORING (ASTM D-1586) Client: EDC, Inc. Project: Industrial Ave 3 Fort Pierce, FL Elevation: Existing Grade Water Level: 4.4 feet after 0 hours Drilling Fluid commenced at depth of 10 feet Project No.:17-5667.00 Lab No.: Page: 1 of 1 Date: 8/14/2017 Drill Rig: CME45 Field Party: PM/MM TEST LOCATION: SPT - 4 N27.49458° W80.35138- Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. 200 Content Content 0 2 0-3 SP Gray fine sand 1 ....-1................. 2 3 1 2 .....2................. 4 3 ......6................. 6 12 2 3 - 5% SM Dark brown organically stained fine sand, 10 some silt 4 8 5 ....10................ 10 20 3 12 5/2- 7 SP Brown fine sand 6 8.... 4 7-10 SP Gray fine sand 7 4 8 4 8 .....4................. 3 3 9 -- _ .......4 ........... 7.... 7 5 10 .....3................. 11 ......................... 12 ......................... 13 ......................... 2 13'/2 - 15 SP Gray fine sand 14 3.... Boring Terminated at 15 feet 16 ......................... 17 ......................... 18 ......................... 19 ......................... GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LUCIE. FLORIDA 34986 PHONE: (772) 924-3575 - FAx: (772) 924-3580 STANDARD PENETRATION TEST BORING (ASTM D-1586) Client: EDC,Inc. Project No.: 17-5667.00 Lab No.: Project: Industrial Ave 3 Page: 1 of 1 Fort Pierce, FL Date: 8/14/2017 Elevation: Existing Grade Drill Rig: CME45 Water Level: 4.2 feet after 0 hours Drilling Fluid commenced at depth of 10 feet Field Party: PM/MM TEST LOCATION: SPT - 5 N27.494430 W80.350960 Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. 200 Content Content 2 0-4 SP Gray fine sand 2 2 4 1 2 .....4................. 5 3 ...._5................. 6 11 2 $ 4 ..... ................. 8 4-10 SP-SM Brown fine sand, little silt 8 5 ..... ................. 10 18 3 6 ....10................ 5 -- 7 .....8................. 7 15 4 8 .....6................. 4 9 ...4.........8.... 5 --- 10 .....5................. 12 ......................... 13 ......................... 4 13'h - 15 SP-SM Brown fine sand, little silt 14 5 10 6 15 ..... Boring Terminated at 15 feet 16 ......................... 17 ......................... 18 ............. .......... 19 ......................... ', Since 1988 Florida's Leading Engineering Source AUGER BORING LOGS WITH HAND CONE PENETROMETER (HCP) TESTS Client: EDC, Inc. Project: Industrial Ave 3 Fort Pierce, FL Elevation: Existing Grade Project No: Lab No: Test Date: Technician: 17-5667.00 8/14/2017 PM/MM TEST LOCATION: AB — 1 N27.494160 W80.350760 HCP Depth (feet) Description (color, texture, consistency, remarks) Depth Reading 0-3 Gra fine sand SP MC = 3.2% , %Passin 200 = 2.7% 1 50 3-4 Dark brown fine sand, some silt SM 2 60 4-6 Brown fine sand, trace silt 3 80+ 4 80+ 5 80+ 6 80+ 7 8 9 10 Water table at 4 feet below ground surface TEST LOCATION: AB — 2 N27.493980 W80.350690 HCP Depth (feet) Description (color, texture, consistency, remarks) Depth Reading 0 — 2Y2 Gray fine sand (SP) 1 30 2/= — 3 Dark brown fine sand, little silt (SP-SM) MC = 35.7% , % Passing200 = 8.7% 2 30 3-6 Brown fine sand, trace silt SP 3 80+ 4 80+ 5 80+ 6 7 8 9 10 Water table at 4.2 feet below ground surface Appendix E - Discussion of Soil Groups GFH T DISCUSSION OF SOIL GROUPS COARSE GRAINED SOILS GW and SW GROUPS. These groups comprise well -graded gravelly and sandy soils having little or no plastic fines (less than percent passing the No. 200 sieve). The presence of the fines must not noticeably change the strength characteristics of the coarse -grained friction and must not interface with it's free -draining characteristics. GP and SP GROUPS. Poorly graded gravels and sands containing little of no plastic fines (less than 5 percent passing the No. 200 sieve) are classed in GP and SP groups. The materials may be called uniform gravels, uniform sands or non -uniform mixtures of very coarse materials and very fine sand, with intermediate sizes lacking (sometimes called skip -graded, gap graded or step - graded). This last group often results from borrow pit excavation in which gravel and sand layers are mixed. GM and SM GROUPS. In general, the GM and SM groups comprise gravels or sands with fines (more than 12 percent the No. 200 sieve) having low or no plasticity. The plasticity index and liquid limit of soils in the group should plot below the "A" line on the plasticity chart. The gradation of the material is not considered significant and both well and poorly graded materials are included. GC and SC GROUPS. In general, the GC and SC groups comprise gravelly or sandy soils with fines (more than 12 percent passing the No, 200 sieve) which have a fairly high plasticity. The liquid limit and plasticity index should plat above the "A" line on the plasticity chart. FAR I:MzMI�14_01-107141 ML and MH GROUPS. In these groups, the symbol M has been used to designate predominantly silty material. The symbols L and H represent low and high liquid limits, respectively, and an arbitrary dividing line between the two set at a liquid limit of 50. The soils in the ML and MH groups are sandy silts, clayey silts or inorganic silts with relatively low plasticity. Also included are loose type soils and rock flours. CL and CH GROUPS. In these groups the symbol C stands for clay, with L and H denoting low or high liquid limits, with the dividing line again set at a liquid of 50. The soils are primarily organic clays. Low plasticity clays are classified as CL and are usually lean clays, sandy clays or silty clays. The medium and high plasticity clays are classified as CH. These include the fat clays, gumbo clays and some volcanic clays. GFP OL and OH GROUPS. The soil in the OL and OH groups are characterized by the presence of organic odor or color, hence the symbol O. Organic silts and clays are classified in these groups. The materials have a plasticity range that corresponds with the ML and MH groups. HIGHLY ORGANIC SOILS The highly organic soils are usually very soft and compressible and have undesirable construction characteristics. Particles of leaves, grasses, branches, or other fibrous vegetable matter are common components of these soils. They are not subdivided and are classified into one group with the symbol PT. Peat humus and swamp soils with a highly organic texture are typical soils of the group. GfP SCANNED. BY St. Lucie County GFA INTERNATIONAL FLORIDA'S LEADING ENGINEERING SOURCE Report of Geotechnical Exploration Proposed One -Story Commercial Building Industrial Ave 3 St. Lucie County, Florida August24, 2017 GFA Project No.: 17-5667.00 For: EDC, Inc. Florida's Leading Engineering Source Environmental •Geotechnical • Construction Materials Testing'• Threshold and Special Inspections • Plan Review & Code Compliance August 24, 2017 EDC, Inc. Attention: Jayson Harrison 10250 SW Village Parkway, Ste 201 Port St. Lucie. FL 34987 Site: Proposed One -Story Commercial Building Industrial Ave 3 St. Lucie County, Florida GFA Project # 17-5667.00 Dear Mr. Harrison: GFA Intemational, Inc. (GFA) has completed the subsurface exploration and geotechnical engineering evaluation for the above -referenced project in accordance with the geotechnical and engineering service agreement for this project. The scope of services was completed in accordance with our Geotechnical Engineering Proposal (17-5667.00), planned in conjunction with and authorized by you. EXECUTIVE SUMMARY The purpose of our subsurface exploration was to classify the nature of the subsurface soils and general geomorphic conditions and evaluate their impact upon the proposed construction. This report contains the results of our subsurface exploration at the site and our engineering interpretations of these, with respect, to the project characteristics described to us including providing recommendations for site preparation and the design of the foundation system. Based on a site plan (reproduced as,the Test Location Plan) and conversations with the client, the project consists of constructing a one-story commercial building with a loading dock and associated parking. The building footprint would be on 29,900 square feet. The property does not have an address, and the parcels are identified as PCNs 1429-501-0116-000-4 and 1429- 501-0117-000-1 on the St. Lucie County Property Appraiser's website. We have not received any information regarding structural loads. F.orthe-foundation'recommendations-- presented Jn this: report.we-assutned-the,maximum coliirrin=load-- ill'be-,75:kips:and:the:maximum_wall-loading will be.4_kips;per-linear fdd0We estimate the site is at or near final grade. The recommendations provided herein are based upon the above considerations. If the project description has been revised, please inform GFA International so that we may review our recommendations with respect to any modifications. A total of five (5) standard penetration test (SPT) borings to depths of approximately fifteen (15) feet, and two (2) Auger Borings (AB) to approximately six (6) feet, below ground surface (BGS) were completed for this study. Hand Cone Penetrometer (HCP) tests were conducted at one foot intervals in the auger borings. The HCP test, in conjunction with information about the soil type, is empirically correlated to the relative density of subsurface soils. The locations of the borings performed are illustrated in Appendix B: 'Test Location Plan". 607 NW Commodity Cove- Port St. Lucie, Florida 34986 • (772) 924-3575 • (772) 924-3580 (fax) • www.teamgfa.com OFFICES THROUGHOUT FLORIDA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667, 00 Page 2 of 15 The subsurface soil .conditions :encountered.. at the_ boring locations generally consist of very loose sand (SP) to a depth of 2 feet, loose to medium dense sand (SP) or silty sand (SP- SM,SM) to the boring termination depths. Please refer to Appendix D - Record of Test Borings for a detailed account of each boring. The subsurface soil conditions at the project site are generally favorable for the support of the proposed structure on shallow foundations. An allowable bearing capacity of 2,500 psf may be used for foundation design. The,--subgrade soils should be -improved with.,compaction from _the_ existing grade. prior to constructing the.foundation pads.- The top 2. feet below existing grade should be compacted to a, minimum of-95% density prior to placing fill to achieve final_ grade. Fill (including stemwall backfill) should be placed in 12-inch lifts and compacted to achieve a minimum 95% density. After excavation for footings, the subgrade to a depth of 2 feet below bottom of footings should be compacted to achieve a minimum 95% density. Silty and -clayey soils_were_encountered in..the_borings which .could pose footing bottom .compaction problems. If compaction cannot be attained due to persistent wetness or the water table near the bottom of the footing excavation, or due to silty/clayey soil 'pumping' during compaction, GFA recommends undercutting below bottom of footing and replacement with No. 57 stone, or rock/sand fill for subgrade that cannot be compacted per recommendations (upper 2 feet, more if required to achieve stable subgrade). The rock/sand fill should be compacted and tamped into the excavation and inspected and verified by a representative from GFA, and tested with hand cone penetrometers, probe rods, or density tests We appreciate the opportunity to be of service to you on this project and look forward to a continued association. Please do not hesitate to contact us if you have any questions or comments, or if we may further assist you as your plans proceed. :l21i ' •ert4ficate ofAuth"tion Number 4930 N .44{�I6/5' ' * T€"OF 1� wee w0c oteg1ganager to rid�2.Fe�%r, ,1�Ak653 �,oil 1111p1 Copies: 2, Addressee GFA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 3 of 15 TABLE OF CONTENTS GFAProject # 17-5667.00...............................................................................................1 1.0 INTRODUCTION......................................................................................................4 1.1 Scope of Services....................................................................................................4 1.2 Project Description................................................................................................4 2.0 OBSERVATIONS......................................................................................................4 2.1 Site Inspection.......................................................................................................4 2.2 Field Exploration....................................................................................................5 2.3 Laboratory Analysis...............................................................................................5 3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS..................................6 3.1 General.................................................................................................................6 3.2 Site Preparation....................................................................................................7 3.3 Design of Footings................................................................................................8 3.4 Ground Floor Slabs...............................................................................................8 3.5 Lateral Earth Pressure Coefficients......................................................................9 3.6 Excavation Conditions..........................................................................................9 4.0 PARKING AND ROADWAY CONSTRUCTION RECOMMENDATIONS ............................10 4.1 General................................................................................................................10 4.2 Compacted Subgrade or Embankment Fill..........................................................11 4.3 Stabilized Subgrade.............................................................................................11 4.4 Base Course........................................................................................................11 4.5 Surface Course....................................................................................................12 ---4.6-Goncrete Pavement ........... ......... .................. ...... ....... ............ ........ ........... ..... ................ 12 4.7 Effects of Water.................................................................................................-12 4.8 Construction Traffic..............................................................................................13 4.9 Pavement Site Preparation..................................................................................13 5.0 REPORT LIMITATIONS.........................................................................................14 6.0 BASIS FOR RECOMMENDATIONS..................................................................................14 Appendix A - Vicinity Map Appendix B - Test Location Plan Appendix C - Notes Related to Test Borings Appendix D - Record of Test Borings Appendix E - Discussions of Soil Groups 6FP Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 4 of 15 1.0 INTRODUCTION 1.1 Scope of Services The objective of our geotechnical services was to collect subsurface data for the subject project, summarize the test results, and discuss any apparent site conditions that may have geotechnical significance for building construction. The following scope of services is provided within this report: 1. Prepare records of the soil boring logs depicting the subsurface soil conditions encountered during our field exploration. 2. Conduct a review of each soil sample obtained during our field exploration for classification and additional testing if necessary. 3. Analyze the existing soil conditions found during our exploration with respect to foundation support for the proposed structure. 4. Provide recommendations with respect to foundation support of the structure, including allowable soil -bearing capacity, bearing elevations, and foundation design parameters. 5. Provide criteria and site preparation procedures to prepare the site for the proposed construction. 1.2 Project Description Based on a site plan (reproduced as the Test Location Plan) and conversations with the client, the project consists of constructing a one-story commercial building with a loading dock and associated parking. The building footprint would be on 29,900 square feet. The property does not have an address, and the parcels are identified as PCNs 1429-501-0116-000-4 and 1429- 501-0117-000-1 on the St. Lucie County Property Appraiser's website. We have not received any information regarding structural loads. For the foundation recommendations presented in this report we assumed the maximum column load will be 75 kips and the maximum wall loading will be 4 kips per linear foot. We estimate the site is at or near final grade. The recommendations provided herein are based upon the above considerations. If the project description has been revised, please inform GFA International so that we may review our recommendations with respect to any modifications. 2.0 OBSERVATIONS 2.1 Site Inspection The project site was generally flat and grassy with trees. The grade at the site was estimated to be 3 feet above the adjacent road at the time of drilling. The site was not occupied at the time of drilling. Commercial structures were adjacent to the property. 6FH Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 5 of 15 2.2 Field Exploration A total of five (5) standard penetration test (SPT) borings to depths of approximately fifteen (15) feet, and two (2) Auger Borings (AB) to approximately six (6) feet, below ground surface (BGS) were completed for this study. Hand Cone Penetrometer (HCP) tests were conducted at one - foot intervals in the auger borings. The HCP test, in conjunction with information about the soil type, is empirically correlated to the relative density of subsurface soils. The locations of the borings performed are illustrated in Appendix B: "Test Location Plan". The Standard Penetration Test (SPT) and HCP methods were used as the investigative tools within the borings. SPT tests were performed in substantial accordance with ASTM Procedure D-1586, "Penetration Test and Split -Barrel Sampling of Soils" and the auger borings in substantial accordance with ASTM Procedure D-1452, 'Practice for Soil Investigation and Sampling by Auger Borings". The SPT test procedure consists of driving a 1.4-inch I.D. split -tube sampler into the soil profile using a 140-pound hammer falling 30 inches. The number of blows per foot, for the second and third 6-inch increment, is an indication of soil strength. The soil samples recovered from the soil borings were visually classified and their stratification is illustrated in Appendix D: "Record of Test Borings". It should be noted that soil conditions might vary between the strata interfaces, which are shown. The soil boring data reflect information from a specific test location only. Site specific survey staking for the test locations was not provided for our field exploration. The indicated depth and location of each test was approximated based upon existing grade and estimated distances and relationships to obvious landmarks. The boring depths were confined to the zone of soil likely to be stressed by the proposed construction and knowledge of vicinity soils. 2.3 Laboratory Analysis Soil samples recovered from our field exploration were returned to our laboratory where they were visually examined in general accordance with ASTM D-2488. Samples were evaluated to obtain an accurate understanding of the soil properties and site geomorphic conditions. Laboratorytests were performed on selected samples for soil classification purposes. The samples were tested for moisture content (ASTM D 2216), gradation sieve analysis for clay/silt content determination (ASTM D 422), and organic content (ASTM D 2974). The moisture contents ranged from 3.2 to 35.7 percent and the silticlay content passing the No. 200 sieve ranged from 2.7 to 8.7 percent. The test results are shown on the boring logs. The recovered samples were not examined, either visually or analytically, for chemical composition or environmental hazards. GFA would be pleased to perform these services for an additional fee, if required. 2.4 Geomorphic Conditions The geology of the site as mapped on the USDA Soil Survey website consists of Lawnwood and Myakka sand (21). These are sandy soils and organic soils are not indicated. It should be noted that the Soil Survey generally extends to a maximum depth of 80 inches (approximately 63/4 feet) below ground surface and is not indicative of deeper soil conditions. Boring logs derived from our field exploration are presented in Appendix D: "Record of Test Borings". The boring logs depict the observed soils in graphic detail. The Standard Penetration GFA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 6 of 15 Test borings indicate the penetration resistance, or N-values, and the auger borings the HCP values logged, during the drilling and sampling activities. The classifications and descriptions shown on the logs are generally based upon visual characterizations of the recovered soil samples. All soil samples reviewed have been depicted and classified in general accordance with the Unified Soil Classification System, modified as necessary to describe typical Florida conditions. See Appendix E: "Discussion of Soil Groups", for a detailed description of various soil groups. The subsurface soil conditions encountered at the boring locations generally consist of very loose sand (SP) to a depth of 2 feet, loose to medium dense sand (SP) or silty sand (SP- SM,SM) to the boring termination depths. Please refer to Appendix D - Record of Test Borings for a detailed account of each boring. 2.5 Hydrogeological Conditions On the dates of our field exploration, the groundwater table was encountered;at depths ranging from.approximately 3%.to 5-feet below the.existing.ground_surface. The groundwater table will fluctuate seasonally depending upon local rainfall and other site specific and/or local influences. Brief ponding of stormwater may occur across the site after heavy rains. No additional investigation was included in our scope of work in relation to the wet seasonal high groundwater table or any existing well fields in the vicinity. Well fields may influence water table levels and cause significant fluctuations. If a more comprehensive water table analysis is necessary, please contact our office for additional guidance. 3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS 3.1 General A foundation system for any structure must be designed to resist bearing capacity failures, have settlements that are tolerable, and resist the environmental forces that the foundation may be subjected to over the life of the structure. The soil bearing capacity is the soil's ability to support loads without plunging into the soil profile. Bearing capacity failures are analogous to shear failures in structural design and are usually sudden and catastrophic. The amount of settlement that a structure may tolerate is dependent on several factors including: uniformity of settlement, time rate of settlement, structural dimensions and properties of the materials. Generally, total or uniform settlement does not damage a structure but may affect drainage and utility connections. These can generally tolerate movements of several inches for building construction. In contrast, differential settlement affects a structure's frame and is limited by the structural flexibility. The subsurface soil conditions at the project site are generally favorable for the support of the proposed structure on shallow foundations. An allowable bearing capacity of 2,500 psf may be used for foundation design. Expected settlement of the structure is 1 inch or less total and less than inch differential. 6FH Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 7 of 15 3.2 Site Preparation GFA recommends the following compaction requirements for this project: Proof Roll......................................................................95% of a Modified Proctor 9 Building Pad Fill............................................................95% of a Modified Proctor Footings........................................................................95% of a Modified Proctor The compaction percentages presented above are based upon the maximum dry density as determined by a "modified proctor" test (ASTM D-1557). All density tests should be performed to a depth of 2 feet below stripped surface and below bottom of footings. Or All density tests should be performed using the nuclear method (ASTM D-2922), the sand cone method (ASTM D-1556), or Hand Cone Penetrometer (HCP) tests. Our recommendations for preparation of the site for use of shallow foundation systems are presented below. This approach to improving and maintaining the site soils has been found to be successful on projects with similar soil conditions. Initial site preparation should consist of performing stripping (removing surface vegetation, near surface roots, and other deleterious matter) and clearing operations. This should be done within, and to a distance of five (5) feet beyond, the perimeter of the proposed building footprint (including exterior isolated columns). Foundations and'any below grade remains of any structures that are within the footprint of the new construction should be removed, and utility lines should be removed or properly abandoned so as to not affect structures. 2. Following, site_ stripping and, priortheLplacement:-of_any_:fill„areas._of su_rficial. sand_ (not. exposed hmestone)ahould: be_compacted_("proof-rolled'') and.tested:. We recommend using a steel drum vibratory roller with sufficient static weight and vibratory impact energy to achieve the required compaction. If the subgrade is too wet or the inflow of groundwater — -cannot-be-controlled_so_that-the compaction is not achievable, then very clean granular fill may be placed up to 1 foot above the water table, intensively densified and compacted until no further settlement can be visually discerned at the fill surface, and 1 foot of soil both above and below the water table have achieved at least 95% density. Density tests should be performed on the proof rolled surface at a frequency of not less than one test per 2,500 square feet, or a minimum of three (3) tests, whichever is greater. Areas of exposed intact limestone shall be visually confirmed by the project geotechnical engineer prior to fill placement, in lieu of proof rolling. 3. Fill material may then be placed in the building pad as required. The fill material should be inorganic (classified as SP, SW, GP, GW, SP-SM, SW-SM, GW-GP, GP -GM) containing not more than 5 percent (by weight) organic materials. Fill materials with siltfclay-size soil fines in excess of 12% should not be used. Fill should be placed in lifts with a maximum lift thickness not exceeding 12-inches. Each lift should be compacted and tested prior to the placement of the next lift. Density tests should be performed within the fill at a frequency of not less than one test per 2,500 square feet per lift in the building areas, or a minimum of three (3) tests per lift, whichever is greater. 6FA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 8 of 15 4. For any footings bearing on a limestone formation, the bottom of all footing excavation shall be examined by the engineer / geologist or his representative to determine the condition of the limestone. The limestone shall be probed for voids and loose pockets of sand. Such areas shall be cleaned to depth of 3 times the greatest horizontal dimension and backfilled with lean concrete. 5. For footings placed on structural fill or compacted native granular soils, the- bottom- of -=all footings shall -be tested -for,compaction..;and examined by the engineer / geologist or his representative -to determine -if the -soil -is free of organic -and/or deleterious material. Density tests should be performed at a frequency of not less than one (1)-density.. test_ per _each isolated .column -footing and one_(_1.)_test- per- each_ seventy.-_five_(75)= lineal Jeet..of -wall footings. If compaction cannot be attained due to persistent wetness or the water tablet near the bottom of the footing excavation, or due to silty/clayey soil 'pumping' during compaction, GFA recommends undercutting below bottom of footing and replacement with No. 57 stone, or rock/sand fill for subgrade that cannot be compacted. The rock/sand fill should be compacted and tamped into the excavation and inspected and verified by a representative from GFA, and tested with hand cone penetrometers, probe rods, or density tests. 6. The contractor should take into account the final contours and grades as established by the plan when executing his backfilling and compaction operations. Using vibratory compaction equipment at this site may disturb adjacent structures. We recommend that you monitor nearby structures before and during proof -compaction operations. A representative of GFA International can monitor the vibration disturbance of adjacent structures. A proposal for vibration monitoring during compaction operations can be supplied upon request. 3.3 Design of Footings Footings may be designed using an allowable soil bearing pressure of 2,500 psf. Shallow foundations should be. embedded a. minimum of 12_inches below final grade. This embedment shall be measured from the lowest adjacent grade. Isolated column footings should be at least 24 inches in width and continuous strip footings should have a width of at least 16 inches regardless of contact pressure. Once site preparation has been performed in accordance with the recommendations described in this report, the soil should readily support the proposed structure resting on a shallow foundation system. Settlements have been projected to be less than 1-inch total and '/z-inch differential. All footings and columns should be structurally separated from the floor slab, as they will be loaded differently and at different times, unless a monolithic mat foundation is designed. 3.4 Ground Floor Slabs The ground floor slabs may be supported directly on the existing grade or on granular fill following the foundation site preparation and fill placement procedures outlined in this report. For purposes of design, a coefficient of subgrade modulus 150 pounds per cubic inch may be 6fA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 9 of 15 used. The ground floor slab should be structurally separated from all walls and columns to allow for differential vertical movement unless a monolithic foundation is used. Excessive moisture vapor transmission through floor floor coverings as well as cause other deleterious retarder should be placed beneath the floor slab to building through the slab. The retarder should b applicable ASTM procedures including sealing arou foundations. 3.5 Lateral Earth Pressure Coefficients slabs -on -grade can result in damage to affects. An appropriate moisture vapor reduce moisture vapor from entering the e installed in general accordance with nd pipe penetrations and at the edges of GFA recommends that cantilever retaining walls for truck docks be designed to resist the "active" earth pressure. Where the top of the retaining wall and the junctions between the two retaining walls is restrained against movement, we recommend that "at rest" earth pressure should be used for design. The recommended soil parameters for the design of the retaining walls are presented in the table below. Additional wall loading from forklifts and food/grocery goods stockpiled near the wall should be accounted for in the design. DESIGN COEFFICIENTS Design Parameter Recommended Value Soil Friction Angle (0) (deg) 30 At -rest Earth Pressure Coefficiemt K. 0.50 Active Earth Pressure Coefficiemt Ka 0.33 Passive Earth Pressure Coefficiemt K. 3.0 Hydrostatic Pressure for Design yw 62.4 Coefficient -of -Wall Friction-Between_Concrete_and_In-situ_Soils 0 35 Modulus of Subgrade Reaction K, 150 pci Dry Unit Weight of Soil yd 105 pcf Wet Unit Weight of Soil y„,e, 110 pcf Effective Unit Weight of Soil yff 48 pcf The earth coefficients presented above assume the retaining walls would be backfilled with clean granular soils. Where the potential exists for buildup of hydrostatic pressure due to the water table, hydrostatic pressure should be assumed and added to the earth pressure for design, unless drainage is provided behind the retaining wall. 3.6 Excavation Conditions In Federal Register, Volume 54, No. 209 (October 1989), the United States Department of Labor, Occupational Safety and Health Administration (OSHA) amended its "Construction Standards for Excavations, 29 CFR, part 1926, Subpart P". This document was issued to better insure the safety of workmen entering trenches or excavations. It is mandated by this federal C,FA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 10 of 15 regulation that all excavations, whether they be utility trenches, basement excavations or footing excavations, be constructed in accordance with the OSHA guidelines. The contractor is solely responsible for designing and constructing stable, temporary excavations and should shore, slope, or bench the sides of any excavations deeper than 4 feet as required to maintain stability of both the excavation sides and bottom. The contractor's responsible person, as defined in 29 CFR Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety procedures. In no case should slope height, slope inclination, or excavation depth, including utility trench excavation depth, exceed those specified in local, state, and federal safety regulations. GFA is providing this information solely as , responsibility for construction site safety or the being implied and should not be inferred. service to our client. GFA is not assuming contractor's activities; such responsibility is not 4.0 PARKING AND ROADWAY CONSTRUCTION RECOMMENDATIONS 4.1 General Projected traffic loadings were unavailable at the time of this report. Flexible pavement structures in this geographic area typically consist of an asphaltic wearing course, a base course, and a stabilized subgrade. As an option, concrete pavements can also be utilized and constructed directly on top of prepared grades or on top of a base course and stabilized subgrade for heavier loads. Based on our experience in the area and the anticipated traffic weights, the typical pavement section thicknesses are provided in Table F below: Table F: Typical Pavement Section Recommendations Type of Layer Material Description Layer Thickness Pavement LiahtDutv/1 Heav Dut Flexible (A) FDOT Type S (non FDOT) or SP 1:5, 2.5 FDOT (B) Crushed Base with minimum LBR ;6, 8 OF 100, compacted to 98% of the modified Proctor maximum dry density (SSG) Stabilized sub -grade fill (LBR 40), 12, 12 compacted to 98% of the modified Proctor maximum dry density STRUCTURAL NUMBER (SN) 2.7 3.5 Rigid _k (C) Florida DOT Portland Cement NA 8 Concrete (B) Crushed Limerock with minimum NA - LBR OF 100, compacted to 98% of the modified Proctor maximum dry density (CSG) Compacted sub -grade fill, NA 12 compacted to 98% of the modified Proctor maximum dry density 6fA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 11 of 15 Parking lots — light duty: auto parking areas; light panel and pickup trucks; 10,000 18-kip equivalent axle loads for a 20 year design life Parking lots — heavy duty: shopping center driveways; delivery vehicles and semi -trucks; 50,000 18-kip equivalent axle loads for a 20 year design life 4.2 Compacted Subgrade or Embankment Fill The subgrade or embankment fill is the layer that supports the structural pavement section. Subgrade and embankment fill should be compacted and in compliance to specifications presented later in the pavement site preparation procedure section of this report. 4.3 Stabilized Subgrade The stabilized subgrade is the portion of the pavement section between the compacted subgrade or embankment fill and the base course. We recommend subgrade material be compacted to 98 percent of the Modified Proctor maximum dry density value (AASHTO T-180). The subgrade material should be stabilized to a minimum Limerock Bearing Ratio (LBR) of 40. As an alternative, the pavement section can be designed using the natural sand and consequently a lower LBR value. If this is desired, an LBR test of the natural sands should be performed and incorporated into a modified pavement design. Perform compliance tests on the stabilized subgrade for full depth at a frequency of one test per 5,000 square feet, or at a minimum of two test locations, whichever is greater. 4.4 Base Course The base course is the portion of the pavement section between the surface course and stabilized subgrade. In areas where separation of at least 1% feet between the estimated wet seasonal high groundwater table and the bottom of the base material occurs, we recommend the base course be limerock minimum (LBR=100). Limerock material should be mined from an approved source. The limerock should be placed in lifts no greater than 6-inches and compacted to at least 98 percent of the Modified Proctor maximum dry density value (AASHTO T-180). If separation between the estimated wet seasonal high groundwater table and the bottom of the base material is less than 1'% feet, we recommend that crushed limerock not be used. The base course should be of an asphaltic base (ABC-3 with a minimum Marshall Stability of 1,000 pounds). In addition, to minimize the potential for.perching of the groundwater table, we do not recommend the use of chemically stabilized subgrade (i.e. sludge). Instead, the subgrade should be mechanically stabilized (compacted) to a minimum of 98 percent of the soil's Modified Proctor maximum dry density value (AASHTO T-180). Perform compliance tests on the base course to its respective depth (6" or 8") at a frequency of one test per 5,000 square feet, or a minimum of two test locations, whichever is greater. 6FP Proposed One -Story Commercial Building Industrial Ave 4, St. Lucie County, Florida GFA Project No. 17-5667.00 4.5 Surface Course Geotechnical Report August 24, 2017 Page 12 of 15 The surface course is usually the portion of the pavement section, which is exposed directly to traffic. In the light duty areas where there is occasional truck traffic, but predominantly passenger cars, we recommend using asphaltic concrete, which has a stability of 1,500 pounds. Heavy-duty areas where truck traffic is predominant, we recommend using asphaltic concrete, which has a minimum stability of 1,500 pounds. Asphaltic concrete mixes shall consist of the materials actually used and should concur to a current approved design. Samples of the materials delivered to the project should be tested to verify that the aggregate gradation and asphalt content satisfies the mix design specifications. Asphalt should be compacted to a minimum of 95 percent of the laboratory density. Perform compliance tests on the surface course, by coring to evaluate the material thickness and to perform laboratory densities, at a frequency of one test per 10,000 square feet, or a minimum of two test locations, whichever is greater. 4.6 Concrete Pavement The minimum rigid pavement thickness recommended in this report is based upon concrete with a minimum compressive strength of 4,000 psi. Fill that may be required to raise grades in slab areas should be compacted to at least 98 percent of the Modified Proctor maximum dry density (ASTM D-1557). The pavement slabs should be reinforced to make them as rigid a practical. Proper joints should be provided at the junctions of slabs and foundation systems so that a small amount of independent movement can without causing structural damage. Construction and control joints should be accordance with ACI and Industry practices. Actual pavement section thickness should be provided by the Design Civil Engineer based on traffic loads, volume, and the owner's design life requirements. The above section represents the minimum thickness representative of typical local construction procedures and, as such, periodic maintenance should be anticipated. All pavement materials and construction procedures should conform to the FDOT, American Concrete Institute (ACI), or appropriate city/county requirements. . 4.7 Effects of Water Many roadways and parking areas have prematurely deteriorated due to intrusion of the wet seasonal high groundwater table or surface runoff mitigation. We recommend the roadways and parking areas be constructed with a minimum separation of 1% feet between the wet seasonal high groundwater table and the base course, independent of the type of base material used. In addition, the parking areas should be constructed with full - depth curb sections. Using extruded curb sections, which lie directly on top of the final surface course or eliminating the curbing entirely, may allow migration of runoff and/or irrigation water to migrate between the base and surface course. This migration can result in separation of the surface course from the base course causing a rippling effect, which result in an increase deterioration of the pavement. C,FA 1 r f Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 13 of 15 4.8 Construction Traffic Incomplete pavement sections or areas of pavement designed for light duty traffic will not perform satisfactory under construction traffic loadings. We recommend all construction traffic (i.e. construction equipment, etc.) be re-routed away from these areas or the pavement sections be design to support these loading conditions. 4.9 Pavement Site Preparation Upon review of the site soil data, our recommendations for preparation of the site for pavements are noted below. This approach to improving and maintaining the site soils has been found to be successful with very similar soil conditions. Initial site preparation should consist of performing dewatering operations if necessary prior to any earthwork. 2. The proposed construction limits should be cleared, stripped and grubbed of all construction debris and the existing vegetation and associated root systems to a depth of their vertical reach. This should be done within and to a distance of 5 feet beyond the road perimeter. 3. Prior to any fill operations, the existing ground surface should be compacted. We recommend a medium weight roller be used to prepare the site for the proposed pavement section. Upon completion of the proof -rolling, density tests should be performed at a frequency of one test per 5,000 square feet, or at a minimum of two test locations, whichever is greater, to confirm a minimum compaction compliance of 98 percent of modified proctor maximum density (AASHTO T-180). Should roadway subgrade soils become loose due to groundwater seepage or excessive storm rain runoff the contractor may choose to stabilize this condition by replacing the wet soils with No. 57 stone or equivalent backfill. The Geotechnical Engineer should inspect this improvement prior to construction of the remaining pavement section. 4. Place fill material, as required. The fill material should be inorganic (classified as SP/GW) containing not more than 5 percent (by weight) fibrous organic materials. Fill materials with silt -size soil fines in excess of 5% should not be used, this includes cyclone sand material. Place fill in maximum 12-inch lifts and compact each lift to a minimum density of 98 percent of the Modified Proctor maximum dry density (AASHTO T-180) with a roller as mentioned previously. . 5. Perform compliance tests within the fill at a frequency of not less than one test per 5,000 square feet per lift in the pavement areas, or at a minimum of two test locations, whichever is greater. 6. The appropriate pavement section should be constructed in accordance to specification present earlier in this report. 7. Representative samples of the on -site material and proposed fill material should be collected and tested to determine the classification and compaction characteristics GFA Proposed One -Story Commercial Building Geotechnical Report Industrial Ave 4, St. Lucie County, Florida August 24, 2017 GFA Project No. 17-5667.00 Page 14 of 15 (AASHTO T-180). The maximum dry density, optimum moisture content, and gradation characteristics should be determined. S. The contractor shall take into account the final contours and grades as established by the paving and drainage plan when executing any backfilling and / or compaction operations. Using vibratory compaction equipment at this site may disturb adjacent structures. We recommend that you monitor nearby structures before and during proof -compaction operations. If disturbance is noted, halt vibratory compaction operations and inform GFA immediately. We will review the compaction procedures and evaluate if the compactive effort resulted in a satisfactory subgrade, complying with design specifications. 5.0 REPORT LIMITATIONS This consulting report has been prepared for the exclusive use of the current project owners and other members of the design team for the Proposed Commercial Building located at Industrial Ave 3 in St. Lucie County, Florida. This report has been prepared in accordance with generally accepted local geotechnical engineering practices; no other warranty is expressed or implied. The evaluation submitted in this report, is based in part upon the data collected during a field exploration, however, the nature and extent of variations throughout the subsurface profile may not become evident until the time of construction. If variations then appear evident, it may be necessary to reevaluate information and professional opinions as provided in this report. In the event changes are made in the nature, design, or locations of the proposed structure, the evaluation and opinions contained in this report shall not be considered valid, unless the changes are reviewed and conclusions modified or verified in writing by GFA International. GFA should be provided the opportunity to review the final foundation specifications and review foundation design drawings, in order to determine whether GFA's recommendations have been properly interpreted, communicated and implemented. If GFA is not afforded the opportunity to participate in construction related aspects of foundation installation as recommended in this report or any report addendum, GFA will accept no responsibility for the interpretation of our recommendations made in this report or on a report addendum for foundation performance. 6.0 BASIS FOR RECOMMENDATIONS The analysis and recommendations submitted in this report are based on the data obtained from the tests performed at the locations indicated on the attached figure in Appendix B. This report does not reflect any variations, which may occur between borings. While the borings are representative of the subsurface conditions at their respective locations and for their vertical reaches, local variations characteristic of the subsurface soils of the region are anticipated and may be encountered. The delineation between soil types shown on the soil logs is approximate and the description represents our interpretation of the subsurface conditions at the designated boring locations on the particular date drilled. Any third party reliance of our geotechnical report or parts thereof is strictly prohibited without the expressed written consent of GFA International. The applicable SPT methodology (ASTM D-1586), CPT methodology (ASTM D-3441), and Auger Boring methodology (ASTM D-1452) 6FA Proposed One -Story Commercial Building Industrial Ave 4, St. Lucie County, Florida GFA Project No. 17-5667.00 Geotechnical Report August 24, 2017 Page 15 of 15 used in performing our borings and sounding, and for determining penetration and cone resistance is specific to the sampling tools utilized and does not reflect the ease or difficulty to advance other tools or materials. GFA Appendix A - Vicinity Map GF Vicinity Map Industrial Ave 3 St. Lucie County, FL GFA Project No. 17-5667.00 Legend; Site Location f eYf. ►.. b k.I .a t . tea 0 Note: Aerial Photograph from GoogleEarth Website Appendix B - Test Location Plan 6FH Test Location Plan: Industrial Ave 3, St. Lucie County, FL -Approximate Standard Penetration Test (SPT) Boring & Auger Boring (AB) Locations Appendix C - Notes Related to Borings GfH NOTES RELATED TO RECORDS OF TEST BORING AND GENERALIZED SUBSURFACE PROFILE I. Groundwater level was encountered and recorded (if shown) following the completion of the soil test boring on the date indicated. Fluctuations in groundwater levels are common; consult report text for a discussion. 2. The boring location was identified in the field by offsetting from existing reference marks and using a cloth tape and survey wheel. 3. The borehole was backfilled to site grade following boring completion, and patched with asphalt cold patch mix when pavement was encountered. 4. The Record of Test Boring represents our interpretation of field conditions based on engineering examination of the soil samples. 5. The Record of Test Boring is subject to the limitations. conclusions and recommendations presented in the Report text 6. "Field Test Data' shown on the Record of Test Boring indicated as 11/6 refers to the Standard Penetration Test (SPT) and means I I hammer blows drove the sampler 6 inches. SPT uses a 140-pound hammer falling 30 inches. 7. The N-value from the SPT is the sum of the hammer blows required to drive the sampler the second and third 6- inch increments. 8. The soil/rock strata interfaces shown on the Records of Test Boring are approximate and may vary from those shown. The soil/rock conditions shown on the Records of Test Boring refer to conditions at the specific location tested: soil/rock conditions may vary between test locations. 9. Relative density for sands/gravels and consistency for silts/clays are described as follows: SPT CPT SANDS/GRAVELS SPT CPT SILTS/CLAYS BLOWS/FOOT KG/CM RELATIVE DENSITY BLOWS/FOOT KG/CM4 CONSISTENCY 0-4 0-16 Very loose 0-1 0-3 Very soft 5-10 17-40 Loose 2-4 4-6 Soft II-30 41-120 Medium Dense 5-8 7-12 Firm 31-50 121-200 Dense 9-15 13-25 Stiff 50+ over 200 Very Dense 16-30 25-50 Very stiff >30 >50 Hard 10. Grain size descriptions are as follows: NAME SIZE LIMITS Boulder 12 Inches or more Cobbles 3 to 12 Inches Coarse Gravel 1K to 3 Inches Fine Gravel No. 4 sieve to 3/. inch Coarse Sand No. 10 to No. 4 sieve Medium Sand No. 40 to No. 10 sieve Fine Sand No. 200 to No. 40 sieve Fines Smaller than No. 200 sieve 11. Definitions related to adjectives used in soil/rock descriptions: PROPORTION ADJECTIVE APPROXIMATE ROOT DIAMETER ADJECTIVE <5% Trace Less than 1/32" Fine roots 5%to 12% Little I/32" to %T Small roots 12%to 30% Some ''/.'to I" Medium roots 30%to 50% And Greater than 1" Large roots Organic Soils: Soils containing vegetable tissue in various stages of decomposition that has a fibrous to amorphous texture, usually a dark brown to black color, and an organic odor. Organic Content <25%: Slightly to Highly Organic: 25%to 75%: Muck; >75%: Peat GfH Appendix D - Record of Test Borings GFH r � GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LuclE. FLORIDA 34986 PHONE: (772) 924-3575 - FAX: (772) 924-3580 STANDARD PENETRATION TEST BORING (ASTM D-1586) Client: EDC, Inc. Project No.:17-5667.00 Lab No.: Project: Industrial Ave 3 Page: 1 of I St. Lucie County, FL Date: 8/14/2017 Elevation: Existing Grade Drill Rig: CME-45 Water-Level:-184eet after 0 hours Drilling Fluid commenced at depth of 10 feet Field Party: PM/MM TEST LOCATION: fSPT_- 1' N27A93940 W80.351470 Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. 200 Content Content 0 ......z................ 0 - 3%: SP Light gray fine sand 1 .....4........... 8 1....2 .. I _-- $ 2 ..... ................. 6 3 .... �9�........� 9.. 2 12 3%: - 5 SM Dark brown organically stained fine sand, 4 '-- 12 some silt 5 ..... I o................. 5-6 SP Gray fine sand 6 16 3 6 ....-....... ............ 6- 10 SP Brown fine sand, trace silt 6 7 .....6................. 7 13 4 6 6 7 9 ...... 7........� 4.. 5 10 .....9................. 11 12 .......................... ......................... 13 ......................... 13'/2 - 15 SP Gray fine sand 14 .....4..... ............. 3 I5 .....4......... 7...- 6 Boring Terminated at 15 feet 16 ......................... 17 ......................... 18 .- ....................... 19 .......................... GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LUCIE. FLORIDA 34986 PHONE:(772) 924-3575 - FAX:(772) 924-3580 I STANDARD PENETRATION TEST BORING (ASTM D-15861 I Client: EDC, Inc. Project: Industrial Ave 3 St. Lucie County, FL Elevation: Existing Grade Water_Level:4 feetafter 0 hours Drilling Fluid commenced at depth of 10 feet Project No.:17-5667.00 Lab No.: Page: 1 of 1 Date: 8/14/2017 Drill Rig: CME-45 Field Party: PM/MM TEST LOCATION: 'SPT-211,N27.49383° W80.351060 Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. 200 Content Content 0 3 0-5 SP Gray fine sand 1 3 .......................... 2 .....4...... ............ 3 3 9 2 � 4 ..... .................. 5 -'- 5 .....5.................. 5-7 SM Brown fine sand, some silt -- 6 11 3 6 .....7 ..................... 8 9 7 - 10 SP Brown fine sand, trace silt --- 9 18 4 8 .... ................ 8 10 9 .....' o.......2.c 5 to................. 1 I 12 .......................... .......................... 13 .......................... 4 131/2 - 15 SM Dark brown fine sand, some silt 14 2 6 15 ....-3..... .....5..... Boring Terminated at 15 feet 16 .......................... 17 ......................... 18 .......................... 19 ......................... GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LUCIE. FLORIDA 34986 PHONE:(772) 924-3575 - FAx: (772) 924-3580 I STANDARD PENETRATION TEST BORING (ASTM D-1586) I Client: EDC, Inc. Project: Industrial Ave 3 St. Lucie County, FL Elevation: Existing Grade Water:Levels5_feet after.() -hours Drilling Fluid commenced at depth of 10 feet Project No.:17-5667.00 Lab No.: Page: 1 of 1 Date: 8/14/2017 Drill Rig: CME-45 Field Party: PM/MM TEST LOCATION: f$PT -- 3-? N27.49414° W80.35123° Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. Zoo Content Content 1 0 - 3/: SP Gray fine sand 1 ....-�................. 2 3 1 2 .....2.................. 2 2 3 ......4........._6.... 2 5 3Y2 - 5 SM Dark brown organically stained fine sand, 4 7 some silt 5 .... !0................ 5-7 SP-SM Brown fine sand, little silt 16 20 3 --- 6 ....1 0................ _ 10 10 7-9 SP Brown fine sand 7 13 23 4 8 ...1 .................. 6 10 9 13 �23 5 9 - 10 SP Brown fine sand, trace clay 10 10 ..... ................ 12 ......................... 13 .......................... l3'/z - 15 SP Gray fine sand, trace clay, trace shell 14 .2 2 15 Boring Terminated at 15 feet 16 ......................... 17 ......................... 18 ......................... 19 ......................... GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LUCIE, FLORIDA 34986 PHONE:(772) 924-3575 - FAx: (772) 924-3580 STANDARD PENETRATION TEST BORING (ASTM D-1586) Client: EDC, Inc. Project No.:17-5667.00 Lab No.: Project: Industrial Ave 3 Page: 1 of 1 St. Lucie County, FL Date: 8/14/2017 Elevation: Existing Grade Drill Rig: CME-45 Water;LeveL 4.4�feetafter 0 hours Drilling Fluid commenced at depth of 10 feet Field Party: PM/MM TEST LOCATION: SPT - 4 IN27.49458° W80.351380 Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. 200 Content Content 0 2 0-3 SP Gray fine sand 1 ......�.................. 2 3 1 3 4 '-' 3 6.................. 3 - 5%2 SM Dark brown organically stained fine sand, 6 12 2 some silt 4 ..._10.... ............ 8 5 .....l �................ 10 20 3 6 .....12................. 5%2 - 7 SP Brown fine sand 7 4 , ,,.. , 7-10 SP Gray fine sand 4 8 4 8 4 .......................... 3 9 ......4.........7... 5 10 ...._...... ............ if.......................... i 12 ......................... 13 ......................... 14 .2.... 13%2 - 15 SP Gray fine sand 3 3 6 6 Boring Terminated at 15 feet 16 .......................... - 17 ......................... 11 .............. ............ I9.......................... 11 GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT ST. LUCIE. FLORIDA 34986 PHONE:(772) 924-3575 - FAx: (772) 924-3580 STANDARD PENETRATION TEST BORING (ASTM D-1586) Client: EDC, Inc. Project: Industrial Ave 3 St. Lucie County, FL Elevation: Existing Grade Water) eyel _4:2-feet after 0 hours Drilling Fluid commenced at depth of 10 feet Project No.:17-5667.00 Lab No.: Page: 1 of I Date: 8/14/2017 Drill Rig: CME-45 Field Party: PM/MM TEST LOCATION: 'SPT wS `N27.494430 W80.350960 Laboratory Tests Depth Blows/ N Sample Layer: USCS Description Passing Moisture Organic (feet) 6 in. Value No. From/to No. 200 Content Content 2 0-4 SP Gray fine sand --- 2 1 ..... 2 2 .....4.................. 5 --- 3 .....5................. 6 11 2 --- $ 4 ..... ................. 8 4-10 SP-SM Brown fine sand, little silt 5 ...._$.................. 10 18 3 6 ....10................ 5 7 .....8................. 7 IS 4 6 3 4 q......4.........g.... 5 to..... ................. 12 .......................... 13 .......................... 4 13%: - 15 SP-SM Brown fine sand, little silt 14 5 6 15...._5.........10... Boring Terminated at 15 feet 16 ......................... 17 ......................... 18 .......................... 19 .......................... 0100- Since 1988 Florida's Leading Engineering Source AUGER BORING LOGS WITH HAND CONE PENETROMETER (HCP) TESTS Client: EDC, Inc. Project: Industrial Ave 3 St. Lucie County, FL Elevation: Existing Grade Project No: Lab No: Test Date: Technician: 17-5667.00 8/14/2017 PM/MM TEST LOCATION: AB — ;; N27.49416` W80.35076° HCP Depth (feet) Description (color, texture, consistency, remarks) Depth Reading 0 — 3 Gray fine sand (SP) (MC = 3.2% , % Passing 200 = 2. %) 1 50 3-4 Dark brown fine sand, some silt SM 2 60 4-6 Brown fine sand, trace silt 3 80+ 4 80+ 5 80+ 6 80+ 7 8 9 10 Water fable at 4'feetbelow ground -`surface TEST LOCATION: `AB - 2 N27.493980 W80.350690 HCP Depth (feet) Description (color, texture, consistency, remarks) Depth Reading 0 — 2%: Gray fine sand (SP) 1 30 2/z — 3 Dark brown fine sand, little silt (SP-SM) MC = 35.7% , % Passing200 = 8.7%) 2 30 3-6 Brown fine sand, trace silt SP 3 80+ 4 80+ 5 80+ 6 7 8 9 10 VVater fable at 4.2"feet below ground surface Appendix E - Discussion of Soil Groups GFH DISCUSSION OF SOIL GROUPS COARSE GRAINED SOILS GW and SW GROUPS. These groups comprise well -graded gravelly and sandy soils having little or no plastic fines (less than percent passing the No. 200 sieve). The presence of the fines must not noticeably change the strength characteristics of the coarse -grained friction and must not interface with it's free -draining characteristics. GP and SP GROUPS. Poorly graded gravels and sands containing little of no plastic fines (less than 5 percent passing the No. 200 sieve) are classed in GP and SP groups. The materials may be called uniform gravels, uniform sands or non -uniform mixtures of very coarse materials and very fine sand, with intermediate sizes lacking (sometimes called skip -graded, gap graded or step - graded). This last group often results from borrow pit excavation in which gravel and sand layers are mixed. GM and SM GROUPS. In general, the GM and SM groups comprise gravels or sands with fines (more than 12 percent the No. 200 sieve) having low or no plasticity. The plasticity index and liquid limit of soils in the group should plot below the "A" line on the plasticity chart. The gradation of the material is not considered significant and both well and poorly graded materials are included. GC and SC GROUPS. In general, the GC and SC groups comprise gravelly or sandy soils with fines (more than 12 percent passing the No, 200 sieve) which have a fairly high plasticity. The liquid limit and plasticity index should plat above the "A" line on the plasticity chart. FINE GRAINED SOILS ML and MH GROUPS. In these groups, the symbol M has been used to designate predominantly silty material. The symbols L and H represent low and high liquid limits, respectively, and an arbitrary dividing line between the two set at a liquid limit of 50. The soils in the ML and MH groups are sandy silts, clayey silts or inorganic silts with relatively low plasticity. Also included are loose type soils and rock flours. CL and CH GROUPS. In these groups the symbol C stands for clay, with L and H denoting low or high liquid limits, with the dividing line again set at a liquid of 50. The soils are primarily organic clays. Low plasticity clays are classified as CL and are usually lean clays, sandy clays or silty clays. The medium and high plasticity clays are classified as CH. These include the fat clays, gumbo clays and some volcanic clays. GfP OL and OH GROUPS. The soil in the OL and OH groups are characterized by the presence of organic odor or color, hence the symbol O. Organic silts and clays are classified in these groups. The materials have a plasticity range that corresponds with the ML and MH groups. HIGHLY ORGANIC SOILS The highly organic soils are usually very soft and compressible and have undesirable construction characteristics. Particles of leaves, grasses, branches, or other fibrous vegetable matter are common components of these soils. They are not subdivided and are classified into one group with the symbol PT. Peat humus and swamp soils with a highly organic texture are typical soils of the group. 6FH