TIERRA SOUTH FLORIDA, INC. Geotechnical Engineering / Material Testing / Inspection Services

Transcription

1 TIERRA SOUTH FLORIDA, INC. Geotechnical Engineering / Material Testing / Inspection Services November 12, 2015 WANTMAN GROUP, INC Vista Parkway, Suite 100 West Palm Beach, FL Attn: Mr. Brian J. LaMotte, P.E., LEED AP RE: Geotechnical Engineering Services Report Proposed East Main Street Place Pahokee, Florida TSF Project No.: Dear Brian: Tierra South Florida, Inc. (TSF) has completed the geotechnical study for the subject project. This geotechnical study was performed in general accordance with the FDOT/Palm Beach County procedures. This report presents the results of our study and includes our evaluation of the soil and groundwater conditions, geotechnical recommendations for roadway improvements. If you have any questions or comments regarding this report, please contact our office at your earliest convenience. Sincerely, TIERRA SOUTH FLORIDA, INC. Wenbin Zhao, Ph.D., P.E. Ramakumar Vedula, P.E. Project Engineer Principal Engineer FL Registration No FL Registration No VISTA PARKWAY, SUITE 10; WEST PALM BEACH, FLORIDA (561) ; FAX (561) State of Florida Professional Engineers License #28073

2 Table of Contents 1.0 PROJECT DESCRIPTION SCOPE OF SERVICES RESULTS OF SUBSURFACE EXPLORATION Review of USDA Soil Survey, Palm Beach County, Florida Field Explorations General Soil Condition Muck Pavement Cores LABORATORY TESTING General GROUNDWATER CONDITIONS Groundwater Seasonal High Groundwater Estimates ENGINEERING EVALUATIONS AND RECOMMENDATIONS - ROADWAY General Permanent Cut and Fill Slopes Excavations Groundwater Control Pavement Design Considerations On-Site Soil Suitability REPORT LIMITATIONS... 6 APPENDIX: USDA Soil Survey Map Boring Location and Soil Profiles Pavement Core Data Sheet and Photographic Documentation

3 Geotechnical Engineering Services Report 1 Proposed East Main Street Place Pahokee, Florida TSF Project No.: PROJECT DESCRIPTION The project, as we understand it, is a roadway pavement improvement project for East Main Street Place in Pahokee, Florida. The purpose of this study was to provide Geotechnical (i.e. soils and groundwater) input to the design team to assist in evaluation of the merits of the potential roadway improvements. 2.0 SCOPE OF SERVICES The study was performed to obtain information on the existing subsurface conditions for the proposed improvements. The following services were provided: 1. Reviewed readily available published topographic and soils information. This information was obtained from the Soil Survey of Palm Beach County, Florida published by the United States Department of Agriculture (USDA) Natural Resources Conservation Services (NRCS). 2. Performed a Geotechnical field study which included eight (8) auger borings to a depth of 10 feet below existing grade. 3. Obtained eight (8) pavement cores. 4. Classified soil samples using the AASHTO Soil Classification System and performed a limited laboratory testing to establish the soil properties. The laboratory testing included moisture content determination and organic content tests. 5. Prepared this Geotechnical Engineering Service Report for the project. These Geotechnical Services were performed in general accordance with the FDOT Soils and Foundations Handbook.

4 Geotechnical Engineering Services Report 2 Proposed East Main Street Place Pahokee, Florida TSF Project No.: RESULTS OF SUBSURFACE EXPLORATION 3.1 Review of USDA Soil Survey, Palm Beach County, Florida Based on a review of the Palm Beach County, Florida Soil Survey, the project location was mapped as follows: Pahokee muck, drained, frequently ponded, 0 to 1 Torry muck Urban land The USDA soil survey map is presented in Appendix. 3.2 Field Explorations The subsurface conditions along the project corridor were explored by eight (8) auger borings to a depth of 10 feet below existing grade. The boring was located in the field by TSF personnel using a hand-held GPS system. Approximate locations of the borings are presented in Appendix. The soil samples of the in-place soils were placed in airtight jars and returned to our laboratory for classification by a geotechnical engineer. The samples were visually classified in general accordance with the AASHTO Soil Classification System for roadway improvements. 3.3 General Soil Condition The soil types encountered in the borings for the roadway improvement have been assigned a stratum number. The stratum numbers and soil types encountered are listed below. Stratum Number Typical Soil Description AASHTO Classification FDOT Soil Designation 1 Asphalt -- Unsuitable 2 Light brown limerock (base) A-1-b Select 3 Dark brown organic silt A-8 Unsuitable 4 Light brown limestone Soil profiles encountered in the borings are presented in Appendix. A Geotechnical engineer bases soil stratification on a visual review of the recovered samples, laboratory testing, and interpretation of the field boring logs. The boring stratification lines represent the approximate boundaries between soil types of significantly different engineering properties; however, the actual transition may be gradual. In some cases, small variations in properties not considered pertinent to our engineering evaluation may have been abbreviated or omitted for clarity. The boring profiles represent the conditions at the particular boring location and variations do occur and should be expected among the borings.

5 Geotechnical Engineering Services Report 3 Proposed East Main Street Place Pahokee, Florida TSF Project No.: Muck Muck was encountered in the borings from the bottom of the existing pavement based course to a depth of about 6 feet below the existing grade. These soils are identified as Stratum 3 (Muck). The thickness of this stratum, typically, is about 5 to 6 feet. These organic soils will need to be removed and replaced with engineered fill materials. 3.5 Pavement Cores Eight (8) pavement cores were obtained on the existing roadway pavement. The pavement core locations, data sheet, and the photo of the recovered pavement core are attached in Appendix. 4.1 General 4.0 LABORATORY TESTING Representative soil samples collected from the borings were classified and stratified in general accordance with the AASHTO Soil Classification System. Our classification was based on visual inspection, using the results from the laboratory testing as confirmation. The laboratory tests performed include natural moisture content test, full sieve analysis, and organic content tests. 5.1 Groundwater 5.0 GROUNDWATER CONDITIONS Encountered groundwater depth was measured at the boring locations following termination of drilling. The encountered groundwater is presented on the soil profiles on Sheet 1 in Appendix. Groundwater conditions will vary with environmental variations and seasonal conditions, such as the frequency and magnitude of rainfall patterns, as well as man-made influences (i.e. existing canals, swells, drainage ponds, under drains, and areas of covered soils, like paved parking lots and sidewalks). Fluctuation should be anticipated. We recommend that the contractor determine the actual groundwater levels at the time of construction to determine groundwater impact on his construction procedure. 5.2 Seasonal High Groundwater Estimates Seasonal high groundwater levels are expected to be controlled by existing drainage features present in the project vicinity. Estimated seasonal high groundwater table levels are expected at elevation from about +10 to +11 feet, NGVD This estimate is based on the Altitude of Water Table, Surficial Aquifer, Palm Beach County, Florida, April 24-26, 1984, published by USGS.

6 Geotechnical Engineering Services Report 4 Proposed East Main Street Place Pahokee, Florida TSF Project No.: ENGINEERING EVALUATIONS AND RECOMMENDATIONS - ROADWAY 6.1 General In general, the existing shallow subsurface soils encountered in the borings are suitable for supporting the proposed roadway extension after proper subgrade preparation. Site preparation should consist of normal clearing and grubbing followed by compaction of subgrade soils. The removal of topsoil where required should be accomplished in accordance with the Florida Department of Transportation (FDOT) Standard Specifications Section 110 Clearing and Grubbing. Backfill should consist of materials conforming to FDOT Standard Index 505 and compacted in accordance with Section of the Standard Specification for Road and Bridge Construction, latest edition. 6.2 Permanent Cut and Fill Slopes We anticipate that fills will be required for the proposed roadway improvements. Assuming proper subgrade preparation and adequate fill materials are utilized, we recommend that all proposed permanent side slopes be constructed on 2.0 horizontal to 1.0 vertical (2H:1V) or flatter. To prevent minor sloughing at the surface, we recommend that the slopes be seeded, mulched and maintained to enhance slope stability soon after being completed. 6.3 Excavations All excavations should be performed in accordance with FDOT Standard Index 500, the latest Standard Specifications for Road and Bridge Construction, and in accordance with OSHA Standards. We recommend that sides of temporary excavations be sloped to 2H:1V or flatter or supported by temporary shoring. 6.4 Groundwater Control In our opinion, groundwater may not have impact on the proposed roadway improvement project provided that the proposed finish level is at the existing roadway level. However, depending upon groundwater levels at the time of construction, some forms of dewatering may be required for utility excavations. 6.5 Pavement Design Considerations We anticipate that the proposed pavement structure will be a semi-flexible asphaltic concrete section. As indicated above, majority of the borings for the proposed roadway indicated the presence of muck and is therefore considered unsuitable. After appropriately treating these compressible soils, the approved backfill are expected to have modest subgrade strength for pavement support. If a stabilized subgrade is required, we recommend a sand-gravel mixture with a minimum design LBR of 40. Base course should consist of limerock, shellrock or coquina, meeting the

7 Geotechnical Engineering Services Report 5 Proposed East Main Street Place Pahokee, Florida TSF Project No.: minimum requirements of the FDOT Standard Specifications for Road and Bridge Construction, Sections 911, 913 or 915, respectively. The limerock (coquina) should have a minimum LBR value of 100. Both the base and stabilized subgrade should be compacted to at least 98 percent of maximum dry density (AASHTO T-180). Soils classified under stratum 5 consist of organic material (A-8). This material should be removed and replaced with suitable material in accordance with Standard Indices 500 and On-Site Soil Suitability Stratum 1 consists of asphalt pavement. Asphalt pavement should be stripped from the proposed roadway improvement areas in accordance with Standard Specifications Section Clearing and Grubbing. Stratum 2 consists of select materials (A-1-b). This material can be used in subgrade and embankment support and should be utilized according to Standard Index 505. Soils classified under stratum 3 consist of organic material (A-8). This material should be removed and replaced with suitable material in accordance with Standard Indices 500 and 505. Soils classified under stratum 4 consist of limestone. Additional effort will be required excavating this material, especially during utility installation. This material can be porous and difficult for dewatering. This material can be used as select material as long as gradation satisfies the FDOT Standard Specification requirements.

8 Geotechnical Engineering Services Report 6 Proposed East Main Street Place Pahokee, Florida TSF Project No.: REPORT LIMITATIONS Our Geotechnical engineering evaluation of the site and subsurface conditions with respect to the planned roadway improvements and our recommendations for site preparation and foundation construction are based upon the followings: (1) site observations, (2) the field exploratory test data obtained during the geotechnical study, and (3) our understanding of the project information and anticipated final grades as presented in this report. If the final grades vary considerably from those stated, or when final cross-sectional data becomes available, please contact our offices so that we can review our recommendations. Furthermore, upon the discovery of any site or subsurface conditions during construction, which appears to deviate from the data obtained during this Geotechnical exploration, please contact us immediately so that we may visit the site, observe the differing conditions, and evaluate the new information with regards to our evaluation and recommendations contained herein. The recommendations presented previously represent design and construction techniques that we feel are both applicable and feasible for the planned construction. We recommend, however, that we be provided the opportunity to review the final construction plans and the earthwork/roadway embankment construction specifications to evaluate whether our recommendations have been properly interpreted and implemented. This geotechnical report has been prepared for the exclusive use of Wantman Group, Inc. for the specific application to the proposed East Main Street Place improvements in Pahokee, Florida.

9 APPENDIX USDA Soil Survey Map Boring Location and Soil Profiles Pavement Core Data Sheet and Photographic Documentation

10 80 39' 42'' W Soil Map Palm Beach County Area, Florida (East Main Street Place, Pahokee, Florida) 80 39' 25'' W 26 49' 39'' N ' 39'' N ' 30'' N ' 30'' N 80 39' 42'' W N Map Scale: 1:2,130 if printed on A landscape (11" x 8.5") sheet. Meters Feet Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS ' 25'' W Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/9/2015 Page 1 of 3

11 Soil Map Palm Beach County Area, Florida (East Main Street Place, Pahokee, Florida) MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:20,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Palm Beach County Area, Florida Survey Area Data: Version 10, Sep 21, 2015 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: 11, 2011 Dec 15, 2010 Mar The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/9/2015 Page 2 of 3

12 Soil Map Palm Beach County Area, Florida East Main Street Place, Pahokee, Florida Map Unit Legend Palm Beach County Area, Florida (FL611) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 26 Pahokee muck, drained, frequently ponded, 0 to 1 percent slopes % 46 Torry muck % 48 Urban land % Totals for Area of Interest % Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/9/2015 Page 3 of 3

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14 Page No.:1 Project No.: Date: 10/29/15 Name: Pavement Cores- East Main Street PAVEMENT CORING DATA Cored By: Danny Reeves Base Subgrade CRACK Core No. Pavement Core Type Total Core Length (in) Type Thickness (in) Type Thickness (in) Depth (in) Comments ORGANIC SILT (OL; PC-1 ASPHALT 4 1/4 LIMEROCK /4 MUCK) ORGANIC SILT (OL; PC-2 ASPHALT 2 1/4 LIMEROCK /4 MUCK) ORGANIC SILT (OL; PC-3 ASPHALT 3 1/4 LIMEROCK /4 MUCK) PC-4 ASPHALT 2 LIMEROCK 11 ORGANIC SILT (OL; PC-5 ASPHALT 3 1/2 LIMEROCK /2 MUCK) PC-6 ASPHALT 1 3/4 LIMEROCK 10 ORGANIC SILT (OL; PC-7 ASPHALT 2 LIMEROCK 10 2 MUCK) PC-8 ASPHALT 5 3/8 LIMEROCK 14 Note: ORGANIC SILT (OL; MUCK) ORGANIC SILT (OL; MUCK) ORGANIC SILT (OL; MUCK)

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