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HomeMy WebLinkAboutGEOTECHNICAL EXPLORATION9 3 G NTERNATIONAL FLORIDA'S LEADING ENGINEERING SOURCE Report of Geotechnical Exploration gg...T danuary 8, 2014 GFA Project No.: 13-2092.01 For: Phoenix Realty Horner 80ANNM BY St Lucie County Florida's Leading Ei7giereerirrgx Source Environmental - Geotechnical • Construction Materials Testing • Threshold and Special Inspections • Plan Review & Code Compliance January 8, 2014 1 Phoenix Realty Homes Attention: Mr. Alan Tarpell 1760 N. Jog Road, Suite 140 West Palm Beach, Florida 33411 Site: Proposed Tarpon Flats Subdivision - Lots 1.38 Vicinity SW of Bonita Isle Dr. CO-, Al St. Lucie County, Florida GFA Project # 13-20,92.01 Dear Mr. Tarpell: 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 dated December 12, 2013, 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 (author and date unknown) (reproduced in Appendix B - Test Location r!Plans) and conversations with the client, the project consists of constructing one or two-story esidences with shallow foundations. 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 70 kips and the maximum wall loading will be 4 kips per linear foot. GFA estimates that 0 to 2 feet of fill will be required to bring the foundation pads to design grade. A total of thirty-eight (38) Cone Penetrometer Test (CPT). soundings to depths of approximately eighteen (18) to twenty (20) feet, and fourteen (14) Auger Borings (AB) to approximately six (6) and ten (10) feet, below ground surface (BGS) were completed for this study. The subsurface soil conditions encountered at this site generally consist of sand (SP) to the auger boring termination depths of 6 and 10 feet, The CPT soundings generally indicated BGS the soils were medium dense to dense to 18 feet, and then very dense to the sounding termination depths of 18 to 20 feet. Most soundings were terminated due to cone refusal on very dense/hard soils at 18 to 20 feet. The exception was at the boring AB @ Lot 11, where sand with pieces of wood and roots was encountered at 3% to 5 feet deep. Please refer to Appendix E I Record of Test Borings for a detailed account of each boring and sounding. 521 N[W Enterprise Drive Port St. Lucie, Florida 34986 = (772) 924.3575 OFFICES THROUGHOUT FLORIDA ) 924.3580 (fax) o turn geamgfa.com k Proposed Tarpon Flats Subdivision - Lots 1-38 Geotechnical Report St. Lucie County, Florida January 8, 2014 GFA Project No. 13-2029.0 i Page 2 of 10 The subsurface soil conditions at the project site are generally favorable for the support of the proposed structures on shallow foundations. An allowable bearing capacity of 2,500 psf may be used for foundation design. Potentially unsuitable soil (sand with pieces of wood and roots) was encountered at boring AB @ Lot 11 at depths of 31/2 to 5 feet, and GFA recommends that test pits be performed in that area prior to, or during, stripping and clearing. Unsuitable soils may be encountered that roust be excavated and removed to at least 5 feet outside the footprint of the building and then backfilled with compacted structural fill. After excavation and backfill operations (where needed) are completed, the subgrade soils should be improved with compaction from the stripped grade prior to constructing the foundation pads. The top 2 feet below stripped 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. Analysis of the foundation performance under hurricane conditions or other storm events, including the effects of loss of soil support due to scour or other forces, is not within the scope of this report, and the recommendations are valid only for normal conditions. Additional analysis and options for foundation systems with scour conditions or other scenarios can be performed if requested. 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, GF rization Number 4930 1 rtal �Moier for+Gc nical Etigrzer .Vistr�6ton c - i675 E N Copies: r F.. ��; ° f�Oessee 19avid Alker Project Manager ��f i Proposed Tarpon Flats Subdivision - Lots 1-38 Geotechnical Report St. Lucie County, Florida January 8, 2014 GFA Project No. 13-2029.01 Page 4 of 10 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 are 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. i 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 (author and date unknown) (reproduced in Appendix B - Test Location Plans) and conversations with the client, the project consists of constructing one or two-story residences with shallow foundations. 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 70 kips and the maximum wall loading will be 4 kips per linear foot. GFA estimates that 0 to 2 feet of fill will be required to bring the foundation pads to design 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 a few trees. The grade at the site was estimated to be even with the adjacent road at the time of drilling. Residential structures were north of the property. The interior roadways for the subdivision had been constructed. The Atlantic Ocean was about 800 feet east, and the Indian River (Intracoastal Waterway) about to 1 mile west, of the property. A few small residential structures anda dirt parking area are Proposed Tarpon Flats Subdivision - Lots 1-38 Geotechnical Report St. Lucie County, Florida January 8, 2014 GFA Project No. 13-2029,01 Page 5 of 10 shown at the site on aerial historical photographs from the GoogieEarth website dating from 1994 to 2007. 2.2 Field Exploration A total of thirty-eight (38) Cone Penetrometer Test (CPT) soundings to depths of approximately eighteen (18) to twenty (20) feet, and fourteen (14) Auger Borings (AB) to approximately six (6) and ten (10) feet, below ground surface (BGS) were completed for this study. The locations of the soundings and borings performed are illustrated in Appendix B: "Test Location Plan". The Cone Penetrometer Test (CPT) methods were used as the investigative tools. CPT tests were performed in substantial accordance with ASTM Procedure D-3441, "Deep Quasi -Static, Cone and Friction Cone Penetration Tests of Soils" and the auger borings in substantial accordance with ASTM Procedure D-1452, `Practice for Soil Investigation and Sampling by Auger Borings". The soil samples recovered from the soil borings were visually classified and their stratification is illustrated in Appendix E; "Record of Test Borings". It should be noted that soil conditions might vary between the strata interfaces, which are shown. The soil boring and sounding 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 and sounding 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. After a thorough visual examination of the recovered site soils, no laboratory testing was deemed necessary. Bag samples of the soil encountered during our field exploration will be held in our laboratory for your inspection for 30 days and then discarded unless we are notified otherwise in writing. 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 South Florida region is a low probable area of sinkhole development or intense seismic activity. There are no known. fault lines located on or near'the project site. Based on the Seismicity Map of the State of Florida produced by B.G. Reagor 1987, the closest seismic ;activity occurred near Miami in 1945. This event registered a III on the Modified Mercalli Intensity Scale of 1931. This intensity is similar to vibrations like that due to passing of heavy or !heavily loaded trucks. The UBC Seismic Zone Map shows the state of Florida to be located Within a 0 Seismic Zone, and there are typically no seismic analyses required for projects located within 0 Seismic Zone. i l� Proposed Tarpon Flats Subdivision - Lots 1-38 St. Lucie County, Florida GFA Project No. 13-2029, 01 Geotechnical Report January 8, 2014 Page 6 of 10 The geology of the site as mapped on the USDA Soil Survey website consists of Canaveral fine sand, 0 to 5 percent slopes (10), and Palm Beach fine sand, 0 to 5 percent slopes (27). 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/a feet) below ground surface and is not indicative of deeper soil conditions. Please refer to Appendix C - Soil Survey Map for a detailed report for the soil survey. Boring logs derived from our field exploration are presented in Appendix E: "Record of Test Borings". The boring logs depict the observed soils in graphic detail. The CPT soundings indicate the penetration resistance values logged during the test. 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 F: "Discussion of Soil Groups", for a detailed description of various soil groups. The subsurface soil conditions encountered at this site generally consist of sand (SP) to the auger boring termination depths of 6 and 10 feet. The CPT soundings generally indicated BGS the soils were medium dense to dense to 18 feet, and then very dense to the sounding termination depths of 18 to 20 feet. Most soundings were terminated due to cone refusal on very dense/hard soils at 18 to 20 feet. The exception was at the boring. AB @ Lot 11, where sand with pieces of wood and roots was encountered at 3% to 5 feet deep. Please refer to Appendix E - Record of Test Borings for a detailed account of each boring and sounding. 2.5 Hydrogeological Conditions On the dates of our field exploration, the groundwater table was encountered at depths ranging from approximately 4Y4 to 53/ feet below the. existing ground surface. The groundwater table will fluctuate seasonally depending upon local rainfall and other site specific and/or local influences including the water levels in the nearby Intracoastal Waterway (Indian River) and Atlantic Ocean with tidal 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. Proposed Tarpon Flats Subdivision - Lots 1-38 St. Lucie County, Florida GFA Project No. 13-2029.01 Geotechnical Report January 8, 2014 Page 7 of 10 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 structures on shallow foundations. An allowable nearing 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. 3.2 Site Preparation GFA recommends the following compaction requirements for this project: ➢ Proof Roll ..............................................................95% of a Modified Proctor ➢ 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 existing grade and below bottom of footings. 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. 1. Initial site preparation should consist of performing stripping 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). Test, Pits should be performed at Lot 11 and where unsuitable soils are encountered, they should be removed. 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 or pavements. 2. Following site stripping (and excavation where needed) 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 j 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 Proposed Tarpon Flats Subdivision - Lots 1-38 St, Lucie County, Florida GFA Project No. 13-2029, 01 Geotechnical Report January 8, 2014 Page 8 of 10 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. 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. i 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. 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 18 inches below final grade. This embedment shall be measured from the lowest adjacent grade. Isolated column footings should be at least 124 inches in width and continuous strip footings should have a width of at least 18 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. i Proposed Tarpon Flats Subdivision -Lots 1-38 St. Lucie County, Florida GFA Project No. 13-2029.Of 3.4 Ground Floor Slabs Geotechnical Report January 8, 2014 Page 9 of 10 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 used. The ground floor slab should be structurally separated from all walls and columns to allow for differential vertical movement. Excessive moisture vapor transmission through floor slabs -on -grade can result in damage to floor coverings as well as cause other deleterious affects. An appropriate moisture vapor retarder should be placed beneath the floor slab to reduce moisture vapor from entering the building through the slab. The retarder should be installed in general accordance with applicable ASTM procedures including sealing around pipe penetrations and at the edges of foundations. 4.0 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 Tarpon Flats Subdivision - Lots 1-38 located at 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. Analysis of the foundation performance under hurricane conditions or other storm events, including the effects of loss of soil support due to scour or other forces, is not,within the scope of this report, and the recommendations are valid only for normal conditions, Additional analysis and options for foundation systems with scour conditions or other scenarios can be performed if requested. 5.0 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 teaches, 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. l / 1 Proposed Tarpon Flats Subdivision - Lots 1-38 Geotechnical Report St. Lucie County, Florida January 8, 2014 GFA Project -No. 13-2029.01 Page 10 of 10 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) 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. 521 N.W. ENTERPRISE..DRIU; PORT ST. U)CM FLORIDA.34986 PHONE: (772) 924-3575 - :FAli: (772):.92473580 i CONE PEN +TRATION :SOCIa'IDING (A:ST14I.2) 34.41) Client: Phoenix Realty Homes Date: 12/31/2013 Project: Proposed Tarpon Flats Subdivision -.Lots 1-38 Project No.: Lab No.: 13-2092.01 St Lucie County, FL Field Crew: PMII L Rig ID: OsbKosb Location: CP ackN27.50557° ` V80.30724° Page: 1 of 1 Elevation: Existing Grade f-F eld Data i - -- - Cone:l eating; gc{tst) P+S qe-I FR Depth 0 40 80 120 160 200 240 280 320 0 riCtlon Ratio FR 8 i 1 (tsfl (metarcl 7 14 9.4 (0.2 40 50 80 33 0.4 70 90 140 1.9 0.6 130 150 260 0.5 0.8 80 90 160 0.9 1.0 50 60 100 2.6 1.2, 100 120 200 1.3 1.4 110 130 220 1.2 1.6 120 140 240, 1.1 1.8 90 110 ISO 1.5 2.0 70 90 140 1.1 2.2 32 44 64 1.9 2.4 11 20 22 4.8 2.6 12 20 24 33 2.8 35 41 70 1.5 3.0 30 38 60 1.5 3.2 30 37 60 33. 3.4 40 55 80 1.8 3.6 47 58 94. 2.1 3.8 55 70 110 1.2 4.0 60 70 120 1.7 4.2 55 70 110 , 1.2 4.4 50 60 100 13 4.6 60 70 120 1.1 4.8 90 100 ISO 0.7 5.0 90 100 ISO 1.5 5.2 I50 170 300 0.9 5.4 200 220 400 ##fit# 5.6 �.. 250 REF 500 5.8 4�-, .C' 2 n; I I I �• I 40 I P:IProjec1s12013113.209?.Ol Tarpa), Flats, A Lucie Comity(PGoenLt RealtyHoniesj[Geot4ppeudices4ipp 6- CP7'(38) I . MR. S I AUGER BORING LOGS (ASTM D-1452) I Cileht: Phoenix Realty Homes Project No: 13-2092.01 Project: Proposed Tarpon Flats Subdivision - Lots 1-38 Lab No: St. Lucie County, FL Test Date: 12/31/2013 & 1/2/2014 Elevation: Existing Grade - Technician: PM/RL I A yy a � FR!YAT10 AUGER BORING LOGS (ASTM D-1452) Client: Phoenix Realty Homes Project: Proposed Tarpon Flats Subdivision - Lots 1-38 St. Lucie County, FL Elevation: Existing Grade i i Project No: Lab No: Test Date: Technician: 13-2092.01 12/31/2013 & 1 /2/2014 PM/RL TEST LOCATION: AB CPT— Lot 10 Depth feet Description (color, texture, consistenc , remarks 0-1 Brown to qrav fine sand (SP) 1 — 1 % Reddish brown to gray fine sand SP 1% — 2 Light brown fine sand, trace shell SP 2-3 Gra fine sand, trace shell SP 3 - 4 Dark gray fine sand, trace shell SP 4-5 Gra fine sand, trace shell SP 5-6 Grayish brown fine sand, trace shell (SP) ___+wat6r table at 5% feet below ground surface TEST LOCATION: AS @ CPT— Lot 11 Depth (feet) Description (color, texture, consistency, remarks 0-1 Brown fine sand SP I irtlif brown fine sand SP i1% — 3% Gra fine sand, trace shall SP 3'/ — 5 Dark ra fine sand, some roots and pieces of wood (highly organic) SP,PT 5-6 Gray fine sand, trace shell (SP) [ , I Water table at 5 feet below ground surface TEST LOCATION: AS Q CPT— Lot 14 De' th (feet) Description (color, texture, consistency, remarks '0 — 2 L Brown fine sand, trace shell SP 2 — 3 Gra fine sand, trace cla , little shelf SP 3,—SE�#t k ra ish brown fine sand SP 4%2 — Light brown fine sand, trace shell SP 5-6 brown fine sand, little shell (SP) [ I I Water table at 5 feet below ground surface I u� r4AttTio�'�� I AUGER BORING LOGS (ASTM D-1452) Client: Phoenix Realty Homes Project No: Project: Proposed Tarpon Flats Subdivision - Lots 1-38 Lab No: St. Lucie County, FL Test Date: Elevation: Existing Grade Technician: TEST LOCATION: AB @ CPT-- Lot 17 Depth (feet) Description (color, texture consistency, remar 0-1 Brown fine sand, trace shell SP 1 — 3% Li ht brown fine sand, trace shell SP 3% — 4% LION brown fine sand SP 4% — 6 Light brown fine sand little shell (SP) I Water table at 5 feet below ground surface TEST LOCATION: AB @ CPT— Lot 21 Depth (feet) Description (color, texture 0-2 Brownish ra fine sand_, trace shelf SP 2-3 Gra fine sand, trace shell SP 13 — 3% Brown fine sand, trace tree root debris SP 13% — 6 Gra fine sand SP I_Water table at 5 4 feet be ground surface TEST LOCATION: AB CPT— Lot 22 Depth (feet Description (color, texture 6-3 Gra ish brown fine sand SP 3-4 Li ht brown fine sand, trace shell SP 4-6 Li ht brown fine sand, little shell (SP) Water table at 4% feet below ground surface remarks 13-2092.01 12/31/2013 & 1/2/2014 PM/RL ` 7� s� . r rFRIVA�cy � AUGER BORING LOGS (ASTM D-1452) Client: Phoenix Realty Homes Project No: 13-2092.01 Project: Proposed Tarpon Flats Subdivision - Lots 1-38 Lab No: St. Lucie County, FL Test Date: 12/31/2013 & - 1/2/2014 Elevation: Existing Grade Technician: PM/RL TEST LOCATION: AB CPT— Lot 25 Depth feet Description color, texture, consistency, remarks) 0 — %z Brown fine sand, trace shell SP %Z — 1'/ Gra fine sand, little shell SP 1 % — 3 Light brown fine sand, trace shell SP 3-6 Light brown fine sand, little shell (SP) i I Water table at 4% feet below ground surface TEST!LOCATION: AB CPT— Lot 27 Depth feet Description color, texture, consistency, remarks 0 — 1 Brown fine sand SP 1-2 E Li ht ra fine sand, trace shell (SP 2-5 Li ht brown fine sand SP) 5 — 6 Light brown fine sand, little shell (SP) I Water table at 5 feet below ground surface i L AUGER BORING LOGS (ASTM D-1452) Client: Phoenix Realty Homes Project No: 13-2092.01 Project: Proposed Tarpon Flats Subdivision - Lots 1-38 Lab No: St. Lucie County, FL Test Date: 12/31/2013 & Elevation: Existing Grade 1/2/2014 Technician: PM/RL I TEST LOCATION: AB.@ CPT— Lot 33 Depth (feet) Description color, texture, consistency, remarks 0-3 Brown fine sand SP 3-4 Li ht brown fine sand SP 4-6 Li ht brown fine sand, trace shell (SP) I Water table at 5 feet below ground surface I TEST LOCATION: AB CPT— Lot 36 De th feet Description (color, texture, consistent ,remarks 0-2 Brown fine sand SP 2-5 Li ht brown fine sand SP 5 — 6 Light brown fine sand, trace shell (SP) Water table at 4'4 feet below ground surface Appendix F - Discussion of SoH Groups DISCUSSION OF SOIL GROUPS COARSE GRAINED SOILS GVV and Sl1V 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. FIDE 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. G -1 OL and Old GROUPS. The soil in the OL and OH groups are characterized by the presence of organic odor or color, hence the symbol 0. 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 sort 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 info one group with the symbol PT. Peat humus and swamp soils with a highly organic texture are typical soils of the group.