Appendix_6_-_Part_2_GEO_Rpt_-_FullReport_FinalVersion_04.18.22.pdf

5808-A Breckenridge Parkway, Tampa, Florida 33610 Phone: (813) 623-3399, Fax: (813) 623-6636 www.mc2engineers.com

MC Squared, Inc.

Geotechnical Engineering Services Report

Cargo Apron Reconstruction and Replacement for Runway 9-27 with a Taxiway Part 2: Replacement for Runway 9-27 with a Taxiway

St. Pete-Clearwater International Airport, Pinellas County, Florida

Prepared for: Michael Baker International 4211 West Boy Scout Boulevard Suite 500 Tampa, Florida 33607

Prepared by: MC Squared, Inc.

5808-A Breckenridge Parkway Tampa, Florida 33610

MC2 Project No. T062107.069_G Date: April 18, 2022

5808 – A Breckenridge Parkway, Tampa, Florida 33610

Phone (813) 623-3399, Fax (813) 623-6636 www.mc2engineers.com

April 18, 2022

Mr. Nathan Parish, P.E.

Michael Baker International, Inc.

4211 West Boy Scout Boulevard Suite 500 Tampa, Florida 33607

Subject: Geotechnical Engineering Services Report

Cargo Apron Reconstruction and Replacement for Runway 9-27 with a Taxiway Part 2: Replacement for Runway 9-27 with a Taxiway

Dear Mr. Parish:

MC Squared, Inc. (MC2) has completed the geotechnical engineering services for the subject project. The purposes of our services were to evaluate the general subsurface conditions within the footprint of the new Taxiways C and A4 and decommissioned Runway 9-27 and to provide geotechnical engineering recommendations. This report documents our findings and conclusions.

We trust that this report will assist you with the design development and construction of the subject project. We appreciate the opportunity to be of service on this project. Should you have any questions, please do not hesitate to contact us.

Respectfully submitted, MC Squared, Inc.

Maziar Foroutan, PhD Sergio Gomez, M.Sc.

Staff Engineer Geotechnical Engineer

Abner Reis, MSCE, P.E. Ethan H. Drew, P.E.

Senior Geotechnical Engineer Project Engineer Florida License No. 93783 Florida License No. 88622 i

TABLE OF CONTENTS

1 PROJECT INFORMATION

1.1 PROJECT AUTHORIZATION

1.2 PROJECT DESCRIPTION AND BACKGROUND INFORMATION

1.3 SCOPE OF SERVICES

2 SITE CONDITIONS

2.1 SITE LOCATION AND DESCRIPTION

2.2 REVIEW OF GEOLOGICAL SURVEY

2.3 REVIEW OF USGS TOPOGRAPHIC MAPS

3 FIELD EXPLORATION PROGRAM

3.1 GENERAL

3.2 PAVEMENT CORES

3.3 DCP TESTS AND HAND AUGER BORINGS

3.4 SPT BORINGS

3.5 BULK SAMPLING FOR CBR

3.6 DOUBLE RING INFILTROMETER TESTS (DRITS)

3.7 TEST LOCATIONS

4 LABORATORY TESTING PROGRAM

4.1 SOIL CLASSIFICATION TESTING

4.2 LABORATORY SOAKED CBR TESTING

5 GENERAL SUBSURFACE CONDITIONS

5.1 SUBSURFACE CONDITIONS

5.2 GROUNDWATER INFORMATION

6 CONSTRUCTION CONSIDERATIONS/RECOMMENDATIONS

6.1 GENERAL

6.2 SITE EVALUATION

6.3 SITE PREPARATION FOR STRUCTURAL ELEMENTS

6.4 SITE PREPARATION FOR STORMWATER POND

6.5 DEWATERING

6.6 PAVEMENT DESIGN

7 REPORT LIMITATIONS

APPENDIX

Table 6 – Soil Parameters Project Location Map – Sheet 1 USDA Soil Survey/USGS Topographic Map – Sheet 2 Test Location Map – Sheets No. 3 to 6 Subsurface Boring Profiles – Sheets No. 7 to 8 Individual Boring Logs – (14 Pages) Pavement Core/DCP/Subsurface Exploration Summary – (26 pages) Test Procedures Important Information About this Geotechnical-Engineering Report

1 PROJECT INFORMATION

1.1 PROJECT AUTHORIZATION

Our geotechnical engineering services were authorized through a Subconsultant Agreement dated January 27th, 2022, between Michael Baker International, Inc. (MBI) and MC2. Our services have been performed in general accordance with MC2 Proposal No. T062107.069_G dated October 4, 2021.

1.2 PROJECT DESCRIPTION AND BACKGROUND INFORMATION

Project information was provided by Mr. Nathan Parish, P.E. of MBI through e-mailed communication dated August 12 and 24, 2021, and subsequent communications. Information provided to us included a project site map and testing location coordinates to evaluate the present soil conditions within the area of proposed construction of new Taxiway C and Taxiway A4 shown in Sheets No. 3 to 6 in the Appendix.

It is our understanding that the decommissioned Runway 9-27 will be demolished between Taxiway B and Runway 18-36. New Taxiways C and A4 will be constructed in generally the same area. Taxiway C will be designed for ADG III aircraft (A319/A320) with 50 feet wide and turfed shoulders. Taxiway A4 will be designed to the same geometric standards as the other connector Taxiways to Runway 18-36 (ADG/TDG to be verified) and will include paved shoulders.

Construction phasing for Taxiway C will be required to minimize or avoid impact on Taxiways A and B. Construction phasing for Taxiway A4 will be required to avoid or minimize impact to Runway 18-36 and Taxiway A. Based on information provided by MBI, part 2 of the project will include:

• Asphalt pavement demolition (37,700 SY)

• New asphalt pavement

• Taxiway C (50’ X 1,650’)

• Taxiway A4 (75’ X 380’ + Paved shoulders)

• Drainage adjustments

• New pavement marking

• Airfield lighting and signage

If any of this project’s description is incorrect or has changed, please inform MC2 so that we may amend, if appropriate, the information represented in this report.

1.3 SCOPE OF SERVICES

Our scope of services consisted of the following:

1. Reviewed historic plans, as-builts, and readily available subsurface information from previous geotechnical studies performed by MC2 and others that may be provided to us by MBI.

2. Conducted a site reconnaissance of the proposed project location to identify areas with possible access issues for drilling equipment and personnel

3. Located existing utilities by 811 services to mark any underground utilities at the locations of the proposed tests. MBI designated subsurface utility firm provided utility locating services in addition to 811.

4. Coordinated all field work activities through MBI designated airport representatives, including work location, scope of work, schedule, time limitations, working around airport schedules, safety around aircrafts, coordination with air traffic control, coordination of test locations including confirmation of utility conflicts.

5. The following field exploration program was conducted for Part 2 to achieve the project objectives:

a. Fourteen (14) Standard Penetration Tests (SPT) borings to 10 feet below the ground surface (bgs),

b. Three (3) Double Ring Infiltrometer Tests (DRITs) at 2 feet,

c. Four (4) California Bearing Ratio (CBR) tests,

d. Twenty (20) pavement cores; seventeen (17) pavement cores as part of the originally planned scope of work and three (3) extra pavement cores requested by MBI to be added to the originally planned scope of work, and

e. Nine (9) Dynamic Cone Penetrometer (DCP) tests up to 4 feet bgs six (6) DCP tests as part of the originally planned scope of work and three (3) extra DCP tests requested by MBI to be added to the originally planned scope of work.

6. Upon completion of the drilling operations, the boreholes were backfilled using bentonite pellets and soil cuttings topped with high-strength, non-shrink, quick-setting concrete.

7. Measured groundwater table (GWT) depth at the end of drilling.

8. Visually examined all recovered soil samples in the laboratory and performed laboratory tests on selected representative samples to develop the soil parameters for the project, as appropriate. The laboratory testing included percent fines passing the U.S. No. 200 sieve, organic content, and natural moisture content.

The field and laboratory test data were used to develop the following:

1. General assessment of area geology based on our experience, study of geological literature and boring information.

2. General location and description of potentially deleterious materials utilizing soil borings, which may interfere with the proposed design and construction.

3. Geotechnical design parameters for pavement and critical design and/or construction considerations based on the soil and groundwater conditions developed from the field and lab data collected.

4. Groundwater level in the borings and estimates of the seasonal high groundwater table depth at the SPT borings.

5. Estimates of the infiltration rates within the areas of interest (where the DRITs were performed).

6. A Geotechnical Engineering Services Report summarizing our findings and analyses, including recommendations for construction and design soil parameters.

The scope of our services did not include an environmental assessment for determining the presence or absence of wetlands or hazardous or toxic materials in the soil, bedrock, groundwater, or air, on or below or around the project site. Any statements in this report or on the boring profiles regarding odors, colors, unusual or suspicious items or conditions are strictly for the information of our client. In addition, our scope of services did not include an evaluation of sinkholes or sinkhole activity and none were performed.

2 SITE CONDITIONS

2.1 SITE LOCATION AND DESCRIPTION

The site for the proposed construction of Taxiway C and Taxiway A4 is located near the west side of the St. Pete-Clearwater International Airport located at 14700 Terminal Blvd #221, Clearwater, Florida. The general site location is shown on the Project Location Map presented as Sheet No. 1 in the Appendix.

The project area is located between Taxiway B and Runway 18-36. Pavement coring was performed on decommissioned Runway 9-27, Runway 18-36, and Taxiways A, B, C, D, and T. The DCP and SPT boring locations were mainly located on the grass covered lands near the north and south sides of the decommissioned Runway 18-36 (i.e., the area of Construction for New Taxiways), except for two borings located near the west side of Taxiway B. In addition, the DRITs were performed on the grass covered lands located near the west side of Taxiway B and the south side of decommissioned Runway.

Please note that a subsurface investigation was also carried out by MC2 within the active Cargo Apron located near the southwest side of the site (See Geotechnical Engineering Services Report, Cargo Apron Reconstruction and Replacement for Runway 9-27 with a Taxiway, Part 1: Cargo Apron Reconstruction) for additional information.

2.2 REVIEW OF GEOLOGICAL SURVEY

Based on the Web Soil Survey (USDA Soil Survey) for Pinellas County, Florida, as prepared by the U.S. Department of Agriculture Soil Conservations Services (USDA Soil Conservation Service), the USDA Soil Survey identified one major soil type at the project site, which is described below.

Matlacha and St. Augustine soils and Urban land (16) have a parent material of sandy mine spoil or earthy fill and a typical profile of sand from zero (0) to 42 inches followed by fine sand from 42 to 80 inches bgs. The material is somewhat poorly drained and has a high capacity to transmit water. The depth to the groundwater table is about 24 to 36 inches.

The USDA Soil Survey is not necessarily an exact representation of the soils on the site. The mapping is based on interpretation of aerial maps with scattered shallow borings for confirmation. Accordingly, borders between mapping units are approximate and the change may be transitional. Differences may also occur from the typical stratigraphy, and small areas of other similar and dissimilar soils may occur within the soil-mapping unit. As such, there may be differences in the mapped description and the soil test boring descriptions presented in this report. The survey is, however, a good basis for evaluating the shallow soil conditions of the area. The USDA Soil Survey Map is included in the Appendix for information and reference, as necessary.

2.3 REVIEW OF USGS TOPOGRAPHIC MAPS

The U.S. Geological Survey (USGS) maintains a database of historical topographic maps. Based on our review of the U.S. Geological Survey (USGS) Topographic Map, 7.5 Minute Series “Safety Harbor Quadrangle,” the USGS Topographic Maps (TopoView), and drawings provide by MBI, elevation in the vicinity of the proposed Taxiway extension ranges from approximately +6 to +9 feet. These elevations are related to the datum NAVD 1988. A relevant portion of the USGS Topographic Map is presented on Sheet No. 2 in the Appendix for information and reference.

3 FIELD EXPLORATION PROGRAM

3.1 GENERAL

The field exploration program initially consisted of pavement cores, DCP tests with subsequent hand auger (HA) borings, Standard Penetration Tests (SPT) borings to 10 feet bgs, Double Ring Infiltrometer Tests (DRITs) at 2 about feet bgs, and California Bearing Ratio (CBR) tests. An additional field exploration program consisting of extra pavement cores and extra DCP tests with subsequent hand auger (HA) borings was requested by MBI to evaluate the subsurface condition within a distressed pavement area located near the eastern end of the existing Taxiway T.

The field exploration program was performed between February 10, 2022, and March 4, 2022.

The results of the field exploration program are included in the Appendix. The field exploration was performed by MC2 drilling subcontractor GHD and MC2 personnel and overseen by one of MC2’s Florida’s licensed professional engineers, specialized in geotechnical engineering. All field samples will be retained by MC2 for six (6) months from the date of this report unless otherwise requested in writing by MBI. After 6 months, the soil samples and pavement cores will be delivered to the client upon written request or disposed of.

3.2 PAVEMENT CORES

Twenty (20) pavement cores were extracted using a 6-inch diameter core barrel that was advanced through the asphalt pavement and/or concrete sections. This procedure was followed by performing HA borings through the base and subbase material to measure the thickness of the layers.

3.3 DCP TESTS AND HAND AUGER BORINGS

Six (6) Dynamic Cone Penetrometer (DCP) tests were performed at locations selected by MBI in general accordance with ASTM D6951 using the SAPPER ADCP manufactured by Kessler Soil Engineering Products, Inc. These six (6) DCP tests were performed using a 17.6-pound hammer.

The three (3) extra DCP tests were conducted using a manual DCP in general accordance with ASTM D6951. The manual DCP test used a 10.1-pound steel mass falling 22.6 inches to strike an anvil and cone into the subsurface. The relevant hammer’s correction factors were used to determine the DCP index for both automatic and manual hammers. The purpose of the DCP tests was to estimate the in-situ CBR values using the correlations between the DCP index and CBR, recommended by ASTM D6951. The in-situ CBR values (i.e., estimated using the correlation) are not related to a laboratory soaked CBR test but are more of an indicator of existing near surface soil conditions on site. The DCP testing was performed continuously from the ground surface to a depth of approximately 4 feet bgs. This procedure was followed by performing HA borings through the base and subbase material to a maximum depth of approximately 4 feet bgs.

The HA borings were performed using a 3-inch diameter manual bucket auger. Representative soil samples were recovered from the HA borings and transported to our laboratory for further analysis.

At DCP-9, which is located near the southern side of the decommissioned Runway 9-27 and west side of Taxiway A which falls within the area of new Taxiway A4, a remarkably high DCP test results was observed. At this test location, the DCP test was only performed to the depth of 1 foot bgs. It should be noted that a Hand Auger excavation was not feasible due to the high stiffness of the underlying material (possible obstruction) which caused DCP and auger refusal. Our field representative unsuccessfully performed three (3)multiple attempts to advance the DCP test. The multiples attempts were made and shallow refusal was encountered after multiple offsets within a safe distance from the original DCP test location. The data for this test is not presented in this report because we believe the test result is isolated and anomalous and does not represent true site soil condition.

An attempt was made to measure the groundwater level at each of the HA boring locations upon completion of drilling/excavation. The borings were backfilled with soil cuttings upon completion.

3.4 SPT BORINGS

The field exploration program included performing fourteen (14) SPT borings. The SPT borings were advanced to depths of 10 feet bgs using the methodology outlined in ASTM D1586. A summary of this field procedure is included in the Appendix. The HA borings were performed to a depth of about 4 feet to avoid potentially unmarked utilities and to help/aid in the determination of the seasonal high groundwater level (SHWT). Split-spoon soil samples recovered during the performance of the borings were visually classified in the field and representative portions of the soil samples were collected and placed in appropriately labeled airtight glass jars for subsequent confirmatory classifications in our testing laboratory in Tampa, FL.

An attempt was made to measure the groundwater level at each of the SPT boring locations at the end of the drilling operation. The borings were backfilled with bentonite pellets and soil cuttings upon completion.

3.5 BULK SAMPLING FOR CBR

Bulk samples of the surficial soils were collected at four (4) locations selected by MBI and delivered to our testing laboratory in Tampa, FL for California Bearing Ratio (CBR) tests. The samples were obtained at depths ranging from about 6 to 18 inches bgs.

3.6 DOUBLE RING INFILTROMETER TESTS (DRITS)

The DRIT tests were performed at the site between February 10, 2022, and February 16, 2022, in general accordance with ASTM D3385-18. The purpose of the DRIT tests was to estimate the infiltration rate near the soil surface at two (2) locations along the project alignment for new Taxiway C and one (1) location within the area of Taxiway A4.

3.7 TEST LOCATIONS

The approximate locations of the SPT borings, DCP tests, DRITs, and CBR samples are schematically illustrated on a site aerial photograph shown on Sheets No. 3 to 6 in the Appendix.

These locations were provided to MBI and marked in the field by a third party engaged by MBI.

Therefore, the locations indicated should be considered accurate only to the degree implied by the method of locating used.

4 LABORATORY TESTING PROGRAM

4.1 SOIL CLASSIFICATION TESTING

Representative soil samples obtained during our field sampling operation were packaged and transferred to our office and, thereafter, examined by a geotechnical engineer to obtain more accurate descriptions of the existing soil strata. Laboratory testing was performed on selected representative samples as deemed necessary to aid in soil classification and to further define the engineering properties of the soils. The laboratory tests included the following:

• Visual classification in general accordance with applicable procedures (ASTM D2488),

• Two (2) organic content tests (ASTM D2974),

• Ten (10) natural moisture content tests (ASTM D2216), and

• Ten (10) percent fines analyses (ASTM D1140).

The results of these tests are summarized in Table 1. The soil descriptions shown on the logs are based upon visual-manual procedures in accordance with local practice. Soil classification is in general accordance with the Unified Soil Classification System (ASTM D2487) and is also based on visual-manual procedures.

Table 1: Summary of Laboratory Testing

Boring ID (Depth)

(ft)

Moisture Content

Percent Passing No.

200 Sieve

Organic Content

USCS

Classification

TB-1 (0 – 2) 9.2 6.7 - SP-SM

TB-1 (8 – 10) 21.8 5.7 - SP-SM

TB-7 (2 – 4) 19.7 6.9 - SP-SM

TB-7 (6 – 8) 21.5 6.9 - SP-SM

TB-8 (4 – 6) 23.1 6.8 - SP-SM

TB-10 (6 – 8) 22.9 6.0 - SP-SM

TB-13 (4 – 6) - - 1.3 SP-SM

TB-13 (6 – 8) 22.5 9.9 - SP-SM

DCP-4 (3 – 4) - - 2.0 SP-SM

DCP-5 (4 – 5) 22.0 3.9 - SP

DCP-7 (3 – 4) 21.1 1.6 - SP

DCP-8 (2 – 3) 9.9 1.6 - SP

4.2 LABORATORY SOAKED CBR TESTING

Four (4) laboratory-soaked CBR tests were performed on selected samples representing the surficial soils within the proposed Taxiway extension alignment. The CBR test results are presented in the following Table 2 below. CBR tests were performed in general accordance with

ASTM D1883.

Table 2. Summary of Laboratory Soaked CBR Results

Test Number

USCS

Classification

Maximum Dry Density

(pcf)

Optimum Moisture Content

Max

CBR

Values

CBR

Average

CBR -

1σ

Recommended Design CBR (1)

CBR-1 SP, SP-SM 109.0 12.3 26

18 8 10(2) CBR-2 SP, SP-SM 103.1 12.8 17

CBR-3 SP, SP-SM 108.5 12.8 10

CBR-4 SP, SP-SM 108.0 12.4 13 13 - 10(3)

(1) Design CBR provided is one standard deviation below the tested average as recommended by the FAA’s Airport

Pavement Design and Evaluation.

(2) Recommended Design CBR=10 for Taxiway C (see item 6.5 Pavement Design).

(3) Recommended Design CBR=10 for Taxiway A4 (due to the proximity to Taxiway C and lack of additional test results for the computation of the overall average site values.

5 GENERAL SUBSURFACE CONDITIONS

5.1 SUBSURFACE CONDITIONS

The general subsurface conditions encountered during the field exploration are shown on the individual soil boring logs, Sheets No. 3 to 6, and the Pavement Core/DCP/Subsurface Exploration

Summary pages in the Appendix. Soil stratification is based on the examination of recovered soil samples and the interpretation of the field boring logs. The stratification lines represent the approximate boundaries between the soil types. The actual transitions may be more gradual than implied.

Pavement Cores (RC-1 through RC-17 and EC-1 through EC-3)

Generally, A limerock base was encountered at all the coring locations except RC-6 and RC-9 where the concrete and crushed concrete bases were encountered underneath the asphalt. A 6-inch-thick layer of Portland Cement Concrete (CONC) was encountered between the asphalt and limerock base at RC-16. A layer of Sand Asphalt Hot Mix (SAHM) base was encountered below the limerock at RC-2 through RC-5 and RC-8; however, at RC-12 SAHM base was encountered between the asphalt and limerock base. Limerock base was also encountered beneath all the asphalt cores at the three (3) extra coring extracted within the area of Taxiway T.

DCP Tests and Hand Auger Borings (DCP-4 through DCP-9)

In general, the subsurface conditions encountered in the hand auger borings performed adjacent to DCP tests consisted of poorly graded, fine SAND (SP) to fine SAND with silt (SP-SM), and Shelly fine SAND with silt (SP-SM) from the bottom of the existing pavement base to the borings’ termination depths of about 5 feet bgs.

As stated in Section 3.3 of this report, field CBR values were estimated from the DCP test results and presented in Pavement Core/DCP/Subsurface Exploration Summary in the Appendix. The average in-place CBR values obtained from the DCP testing are presented in the following table.

Table 3: Summary of Field CBR Results

DCP Test Location Estimated Average CBR Value*

DCP-4 3

DCP-5 6

DCP-6 4

DCP-7 (**) 16

DCP-8 (**) 16

DCP-9(***) --

*CBR value should be considered an in-situ/in-place value. Average CBR Values for upper 4 feet of subgrade soil only.

** CBR value excluded from the computation of the overall average site values *** CBR value not estimated due to unreliable field test results.

DCP-4 through DCP-8 are located near the northern side of the decommissioned Runway 9-27 which fall within the area of new Taxiway C. We note that DCP tests designated DCP-7 and DCP-8 resulted in significantly higher average in-situ CBR values than the other three DCP tests (DCP-4 through DCP-

6) performed within this area. The relatively higher average in-situ CBR values are likely due to isolated areas with denser shallow soil conditions along the project alignment or localized obstructions. Excluding the DCP test results from DCP-7 and DCP-8, the tests results indicated a mean CBR value of 4.3 with a standard deviation of about 1.5. This correlates to a recommended design CBR of 3.

As stated in Section 3.3 of this report, field DCP test value reported for the DCP-9 resulted in a a remarkably high DCP test results. After several unsuccessful attempts to advance the DCP test, the test results were considered not representative of the true site soil condition and data for this test was not presented in the report.

Three (3) extra DCP tests were performed at the site, upon MBI’s request, to assess the subsurface condition within a distressed pavement area near the eastern end of the existing Taxiway T. The summary of DCP test results for these three (3) extra locations are provided in Table 4. More details can be found in Pavement Core/DCP/Subsurface Exploration Summary in the Appendix.

Table4: Summary of Field CBR Results Based on the Extra DCP Tests

DCP Test Location Estimated Average CBR Value of Base Estimated Average CBR

Value of Subgrade*

DCP-10 100 26

DCP-11 100 34

DCP-12 80 30

*CBR value should be considered an in-situ/in-place value.

Average CBR Values for upper 4 feet of subgrade soil only.

SPT Borings (TB-1 through TB-14)

In general, the subsurface conditions encountered in borings TB-1 through TB-14 consisted of very loose to medium dense, poorly graded, fine SAND (SP) to fine SAND with silt (SP-SM), and Shelly fine SAND with silt (SP-SM) from the ground surface to the boring termination depth of 10 feet bgs. It should be noted that the weight of hammer (WOH) condition was observed at test boring TB-4 from 6 to 7 ½ feet bgs. Soil parameters presented in Table 6 of the Appendix were derived using empirical correlation from FDOT Soils and Foundation Handbook.

DRITs (DRIT-1 through DRIT-3)

The test results include calculated infiltration rates and a brief soil profile at each DRIT test location. The inner ring readings stabilized approximately between 1.5 to 3 hours after the tests started. The average inner ring infiltration rates along with the soil profiles at each DRIT location are provided in Table 5.

Table 5: Summary of DRITs

Location Average Inner

Ring Infiltration Rate (in/hr)

Vertical Permeability (Kv)

(ft/day)

Horizontal Permeability (KH)

(ft/day)

Test Depth

(ft.)

Soil Profile (Depth range): USCS

GWT

(ft)

DRIT-1 3.3 6.6 9.9 2

(0’ – 5’)

SP, SP-SM

DRIT-2 1.9 3.8 5.7 2

(0’ – 4’)

SP, SP-SM

3 ½

DRIT-3 4.7 9.4 14.1 2

(0’ – 5’)

SP, SP-SM

Notes: SP-SM – Poorly graded sand with silt; GWT – Groundwater table

5.2 GROUNDWATER INFORMATION

An attempt was made to measure the groundwater level in the boreholes during and/or upon completion of subsurface exploration operation (i.e., DCP, Hand Auger, and SPT). Generally, the groundwater was encountered between the depth of 3.9 to 5.1 feet bgs except for SPT borings at TB-9 and TB-11 where the groundwater was encountered around 6 to 6.3 feet bgs. We estimate that the Seasonal High-Water Table (SHWT) would be approximately between 2 to 4 feet bgs at each boring location (see Sheets No. 7 to 8 in the Appendix).

This estimate is based upon our review of available publications, the soil samples collected in the field, and groundwater levels for the USCG Air Station H-3 Site provided by MBI. For a more accurate estimation of the SHGWT, we recommend the installation of groundwater monitoring wells (observation wells) at the site near the areas of interest.

Fluctuations in groundwater levels should be anticipated throughout the year primarily due to seasonal variations in rainfall and other factors that may vary from the time the borings were performed.

6 CONSTRUCTION CONSIDERATIONS/RECOMMENDATIONS

6.1 GENERAL

The following evaluations and recommendations have been developed based on the previously described project characteristics, our review of published data, information provided by others, our site reconnaissance and the results of our subsurface exploration and associated laboratory testing. The pavement design for the proposed construction of new Taxiways C and A4 should be performed in accordance with applicable Federal Aviation Administration (FAA) and Florida Department of Transportation (FDOT) specifications. Pavement designs should be based on actual loading and design life.

The following are our recommendations for overall site preparation. These recommendations are made as a guide for the design engineer, parts of which should be incorporated into the project’s general specifications.

6.2 SITE EVALUATION

The following is a summary of our observations and evaluations relating to this project:

1. We compared the USDA soil survey information with the shallow subsurface information collected in our test borings. The data provided in the soil survey indicates sandy mine spoil or earthy fill and a typical profile of sand from zero (0) to 42 inches followed by fine sand from 42 to 80 inches bgs. Our test borings encountered fine SAND (SP) to fine SAND with silt (SP-SM), and Shelly fine SAND with silt (SP-SM). In general, the USDA soil survey information seems to coincide with what was encountered on site.

2. Our review of the USGS topographic maps did not indicate any features that appeared out of the ordinary and does not require further clarification.

3. In general, the SP, SP-SM material encountered in our SPT borings is suitable for use as fill material, so long as the CBR value meets minimum standards for its application.

Recommendations pertaining to selection and placement of fill are presented within this report.

4. According to the FAA’s Advisory Circular AC 150/5320-6G, where the mean subgrade strength is lower than a modulus of 7,500 psi (CBR 5), it will be necessary to improve the subgrade chemically or mechanically. As mentioned above, laboratory soaked CBR testing results suggest a design CBR of 10. Therefore, we are not providing recommendations for chemical and mechanical improvements in this report.

6.3 SITE PREPARATION FOR STRUCTURAL ELEMENTS

1. Site preparation should include stripping and removal of surficial (topsoil) and shallow organics where present prior to replacing with properly compacted structural fill. If unstable soils are encountered during excavation that cannot be adequately densified in place, they should be removed and replaced under the recommendations of the MC2 representative.

2. The natural soil encountered directly underneath any runway/Taxiway excavation should be compacted to 98% of the modified Proctor’s maximum dry density within ± 2% of the optimum moisture content or otherwise specified by applicable FAA and/or FDOT Specifications. If compaction is not practical or the material encountered is unsuitable, then the material should be excavated an additional 6 inches and backfilled with either approved compacted structural fill, lean concrete, or course graded crushed stone wrapped in a geotextile fabric to create a working platform for the runway/Taxiway construction equipment.

3. Fill or backfill material should preferably consist of clean sands (SP) to slightly silty sand (SP-SM), free of organic or other deleterious materials, with less than 12 percent passing the U.S. Sieve No. 200.

4. All fill and backfill material should be placed and compacted in accordance with applicable Federal Aviation Administration (FAA) and Florida Department of Transportation (FDOT) specifications.

5. The fill and backfill should be placed in level lifts not exceeding 12 inches in uncompacted thickness. Each lift should be compacted by repeated passes with appropriate compaction equipment to achieve at least 98 percent of the Modified Proctor Maximum Dry Density (ASTM D1557) or otherwise specified by applicable FAA and/or FDOT Specifications. The filling/backfilling and compaction operations should continue until the desired elevation(s) is achieved.

6. The contractor should exercise caution during construction and compaction of soils so as not to cause settlement of any nearby existing structures or utilities induced by vibrations.

The Contractor must control and adjust the vibration to not disturb existing structures and/or subsurface utilities that may be in the vicinity of the project. In this regard, the Contractor may want to consider using non-vibratory compaction equipment. The contractor is solely responsible for any settlement caused by his actions.

7. If unsuitable soils, as defined by applicable FAA and/or FDOT Specifications, are encountered, these soils would need to be made acceptable by means of chemical or mechanical stabilization. Chemical stabilization requires different stabilizing agents for different soil types. AC 150/5370-10, Items P-155, P-157 and P-158 references multiple publications for modelling chemically stabilized layers. Mechanical stabilization involves excavating and replacing material with either a clean fill, an open-graded aggregate wrapped in geotextile fabric, lean concrete or geosynthetics.

8. Subgrade stabilization should also be considered if any of the following conditions exist:

poor drainage, adverse surface drainage, or need for a stable working platform.

9. The use of soils with relatively high fines content (i.e., clayey soils) as fill should be avoided near the ground surface in green-space areas adjacent to paved areas since these relatively low permeability soils promote ponding of water during and following rainfall.

Also, these relatively low permeability soils should not be used directly beneath any pavement section as they may trap water within the pavement section leading to premature pavement failure.

10. Within the area of new Taxiway A4, a remarkably high DCP test results was observed. At this location, the refusal material was probably isolated and the contractor must be ready to explore and excavate the material and replace with approved structural fill. The contractor should be aware of the possibility of encountering unsuitable materials underneath the existing pavement and should be ready to remove and replace as a foreseen condition.

This unsuitable material should include possible buried organic soil, abandoned utilities, buried foundations, and other below-ground structures such as concrete slabs and concrete hardstands. All the buried underground concrete should be assumed as reinforced concrete.

11. MC2 should be employed by the Owner to observe and test all prepared and compacted areas to document that all unsuitable soils are removed and that the subgrade and fill soils are prepared and compacted in accordance with the above recommendations.

6.4 SITE PREPARATION FOR STORMWATER POND

1. Site preparation for the pond construction should include stripping/removal of topsoil and surface organics and other deleterious materials where present, prior to excavation to design grades. After clearing and excavating, we recommend that the bottom and banks of the pond be lightly compacted (90 to 92% of the soil’s modified Proctor maximum dry density and ±2% of the soils optimum moisture content, in accordance with ASTM D698) or otherwise specified by applicable FAA and/or FDOT Specifications. If fill is needed, it should be placed in level lifts not to exceed 12 inches. loose thickness and compacted similarly.

2. In-place density tests should be performed on each lift by an experienced engineering technician working under the direction of a licensed Geotechnical Engineer to verify that the recommended degree of compaction has been achieved. We suggest the following minimum testing frequency, per layer of fill placed: one test per 2,500 square feet of area.

6.5 DEWATERING

If the control of groundwater is required to perform the necessary earthworks (e.g., stripping, excavation, proof-rolling, filling, compaction, and any other earthwork, site work, and/or subgrade preparation operations), the actual method(s) of dewatering should be determined by the Contractor. Dewatering should be performed to lower the groundwater level to depths that are adequately below excavations and compaction surfaces. Adequate groundwater level depths below excavations and compactions surfaces vary depending on soil type and construction method.

The contractor should be permitted to employ any commonly accepted means and methods necessary to maintain the groundwater level below the bottom of the excavation and to maintain a dry excavation during wet weather. Groundwater levels should be maintained at a minimum of 2 foot below the bottom of the excavations during construction. The placement of backfill, reinforcing steel, or concrete in standing water should not be permitted.

6.6 PAVEMENT DESIGN

According to FAA’s Airport Pavement Design and Evaluation, the design CBR value for subgrade support should be conservatively selected to ensure a stable subgrade and should reflect the long-term subgrade support that will be provided to the pavement. The FAA recommends selecting a CBR design value that is one standard deviation below the mean. If no site preparation is planned (i.e., the subgrade will remain in its present condition), the results of the DCP testing are most suitable for evaluating the subgrade. The DCP testing results suggest a design CBR value of 3 for the proposed construction of Taxiway C. The suggested design CBR value of 3 (based on DCP testing results) should also be used for the design of the proposed Taxiway A4. However, based on our understanding, site preparation is planned for the proposed construction.

Therefore, the FAA’s Airport Pavement Design and Evaluation suggest that the results of the laboratory CBR testing are most suitable for evaluating the subgrade.

As stated in Section 3.3 of this report, field DCP test value reported for the DCP-9 resulted in a very high DCP test results. After several unsuccessful attempts to advance the DCP test, the test results were considered not representative of the true site condition.

As stated in Section 3.5 of this report, four (4) bulk samples of the surficial soils were collected at the site for laboratory CBR testing from depths ranging from about 6 to 18 inches bgs. Based on the laboratory test results, we recommended design CBR=10 for Taxiway C and similarly, we also recommended Design CBR=10 for Taxiway A4 (due to the proximity to Taxiway C and lack of additional test results for the computation of the overall average site values. After comparing the similarity of the subsurface condition between these two (2) locations, we recommend using the site laboratory CBR testing for design of the pavement for these structures.

FDOT Flexible Pavement Design Manual (January 2022 Manual) specifies a minimum base clearance of 3 feet above the SHWT. When the clearance is less than 3 feet, the pavement designer must reduce the design resilient modulus by 25% for a 2 feet base clearance and by 50% for a 1 foot base clearance.

7 REPORT LIMITATIONS

The evaluations and recommendations in this report are based on the data obtained from the soil borings and DCP tests performed at the approximate locations as indicated on Sheets No. 3 to 6 in the Appendix.

This report does not reflect any variations that may occur between the borings. The nature and extent of variations may not become evident until during the course of construction. If variations then appear evident, it will be necessary for a reevaluation of the recommendations of this report to be made after performing on-site observations during the construction period and noting the characteristics of any variations.

When the final design and specifications are completed, we would like the opportunity to review them to determine whether changes in the original concept may have affected the validity of our recommendations and whether these recommendations have been implemented in the design and specifications.

While the borings are representative of subsurface conditions at their respective locations and for their respective vertical reaches, local variations characteristic of the subsurface materials of the region are anticipated and may be encountered. The boring logs and related information are based on the field logs and visual examination of selected sample in the laboratory. The delineation between soil types shown on the logs is approximate and the description represents our interpretation of subsurface conditions at the designated boring locations and on the particular date drilled.

This report has been prepared for the exclusive use of MBI in accordance with generally accepted geotechnical engineering practices. No other warranty, expressed or implied, is made. For additional reference describing the scope and limitations of this geotechnical report, please review the document enclosed in the Appendix titled, “Important Information About this Geotechnical-Engineering Report.”

APPENDIX

Table 6 – Soil Parameters Project Location Map – Sheet 1

USDA Soil Survey/USGS Topographic Map – Sheet 2 Test Location Map – Sheets No. 3 to 6

Subsurface Boring Profiles – Sheets No. 7 to 8 Individual Boring Logs – (14 Pages)

Pavement Core/DCP/Subsurface Exploration Summary – (26 pages) Test Procedures

Important Information About this Geotechnical-Engineering Report

Replacement for Runway 9-24 with Taxiway St. Pete-Clearwater International Airport, Pinellas County, Florida

Table 6: Soil Parameters – Runway 9-24 with Taxiway

Depth Below

Ground Surface (ft)

Average SPT N-

Value Soil Type (Unified)

Approx. Soil Unit Weight Angle of Internal

Friction, φ

(degrees)

Cohesion, c

(psf) γt (pcf) γb (pcf)

TB-1

0 – 4 Hand Auger SP-SM 100 38 29 0

4 – 10 5 SP, SP-SM 105 43 29 0

TB-2

0 – 4 Hand Auger SP-SM 100 38 29 0

4 – 8 8 SP, SP-SM 105 43 30 0

8 – 10 4 SP-SM 100 38 29 0

TB-3

0 – 4 Hand Auger SP-SM 100 38 29 0

4 – 6 12 SP-SM 110 48 31 0

6 – 10 4 SP-SM 100 38 29 0

TB-4

0 – 4 Hand Auger SP, SP-SM 100 38 29 0

4 – 6 6 SP-SM 105 43 30 0

6 – 8 0 SP 100 38 28 0

8 – 10 4 SP-SM 100 38 29 0

TB-5

0 – 4 Hand Auger SP, SP-SM 100 38 29 0

4 – 6 29 SP, SP-SM 115 53 35 0

6 – 10 6 SP-SM 105 43 30 0

TB-6

0 – 4 Hand Auger SP, SP-SM 100 38 29 0

4 – 6 12 SP 110 48 31 0

6 – 10 4 SP-SM 100 38 29 0

Table 6: Soil Parameters – Runway 9-24 with Taxiway

Ground Surface (ft)

Average SPT N-

Value Soil Type (Unified)

Approx. Soil Unit Weight Angle of Internal

Friction, φ

(degrees)

Cohesion, c

(psf) γt (pcf) γb (pcf)

TB-7

0 – 4 Hand Auger SP, SP-SM 100 38 29 0

4 – 6 12 SP, SP-SM 110 48 31 0

6 – 10 5 SP-SM 105 43 29 0

TB-8

0 – 4 Hand Auger SP-SM 100 38 29 0

4 – 10 6 SP-SM 105 43 30 0

TB-9

0 – 4 Hand Auger SP 100 38 29 0

4 – 10 8 SP-SM 105 43 30 0

TB-10

0 – 4 Hand Auger SP, GP 100 38 29 0

4 – 10 8 SP-SM 105 43 30 0

TB-11

0 – 4 Hand Auger SP-SM 100 38 29 0

4 – 6 26 SP-SM 115 53 35 0

6 – 8 16 SP 110 48 32 0

8-10 8 SP-SM 105 43 30 0

TB-12

0 – 4 Hand Auger SP, SP-SM 100 38 29 0

4 – 6 13 SP-SM 110 48 31 0

6 – 10 6 SP-SM 105 43 30 0

TB-13

0 – 4 Hand Auger SP 100 38 29 0

4 – 10 6 SP-SM 105 43 30 0

Note 1: The Hand Auger excavated layers are assumed as loose material

Table 3. Soil Parameters – Runway 9-24 with Taxiway

Ground Surface (ft)

Average SPT N-

Value Soil Type (Unified)

Approx. Soil Unit Weight Angle of Internal

Friction, φ

(degrees)

Cohesion, c

(psf) γt (pcf) γb (pcf)

TB-14

0 – 4 Hand Auger SP, SP-SM 100 38 29 0

4 – 6 11 SP-SM 110 48 31 0

6 – 10 5 SP-SM 105 43 29 0

LEGEND:

Approximate Project Location

Source: Google Earth

Image Date: 5/23/2021

KF

KF

3/10/2022

3/10/2022

T062107.069-G

5808-A Breckenridge Parkway

Tampa, FL 33610

Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants

MC SQUARED, INC.

Graphic Scale (feet)

Approximate

Project Location

0' 1000'500'

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.

Project Location Map

DATE

NAME

Cargo Apron Reconstruction and Replacement for Runway 9-27 With a Taxiway

Part 2: Replacement for Runway 9-27 with a Taxiway

St. Pete-Clearwater, Pinellas County, Florida

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Abner M Reis, P.E.

FLORIDA LICENSE No. 93783

ED

AR 4/6/2022

USDA Soil Survey/USGS Topographic Maps

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.

DATE

NAME

5808-A Breckenridge Parkway

Tampa, FL 33610

Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants

MC SQUARED, INC.

Source: Natural Resources Conservation Service

The survey data is Version 20 dated Jun 8, 2020, with aerial images taken Jan 27, 2020 - Feb 4, 2020.

KF

KF

3/10/2022

3/10/2022

SAFETY HARBOR QUADRANGLE

FLORIDA-PINELLAS CO.

7.5 MINUTE SERIES TOPOGRAPHIC

NAVD: 1988 - DATE: 2018

Project Location

T062107.069-G

Cargo Apron Reconstruction and Replacement for Runway 9-27 With a Taxiway

Part 2: Replacement for Runway 9-27 with a Taxiway

St. Pete-Clearwater, Pinellas County, Florida

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Abner M Reis, P.E.

FLORIDA LICENSE No. 93783

ED

AR 4/6/2022

TB-14

DRIT-3

RC-1

TB-2

TB-3

TB-4

TB-13 DRIT-2

RC-3

DCP-5

CBR-1

RC-2

TB-1

DCP-4

TB-12 DRIT-1

Taxiway T

Taxiway B

Decommissioned Runway 9-27

Source: Google Earth

Image Date: 5/23/2021

Graphic Scale (feet)

0' 200'100'

3/10/2022

3/10/2022

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.

DATE

NAME

LEGEND:

5808-A Breckenridge Parkway

Tampa, FL 33610

Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants

MC SQUARED, INC.

KF

KF

T062107.069-G

Cargo Apron Reconstruction and Replacement for Runway 9-27 With a Taxiway

Part 2: Replacement for Runway 9-27 with a Taxiway

St. Pete-Clearwater, Pinellas County, Florida

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Abner M Reis, P.E.

FLORIDA LICENSE No. 93783

ED

AR 4/6/2022

Approximate Test Locations

Test Location Map

TB-8

TB-7

TB-6

TB-5

RC-4

RC-5

DCP-6

DCP-7

CBR-2

CBR-3

Decommissioned Runway 9-27

Source: Google Earth

Image Date: 5/23/2021

Graphic Scale (feet)

0' 100'50'

3/10/2022

3/10/2022

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.

DATE

NAME

LEGEND:

5808-A Breckenridge Parkway

Tampa, FL 33610

Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants

MC SQUARED, INC.

KF

KF

T062107.069-G

Cargo Apron Reconstruction and Replacement for Runway 9-27 With a Taxiway

Part 2: Replacement for Runway 9-27 with a Taxiway

St. Pete-Clearwater, Pinellas County, Florida

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Abner M Reis, P.E.

FLORIDA LICENSE No. 93783

ED

AR 4/6/2022

TB-9

DCP-8

RC-9

RC-8

RC-7

RC-13

RC-10

RC-11

RC-12

RC-15

RC-17

TB-11

RC-14

TB-10

RC-16

RC-6

DCP-9 CBR-4

Taxiway D

Taxiway A

Decommissioned Runway 9-27

Source: Google Earth

Image Date: 5/23/2021

Graphic Scale (feet)

0' 100'50'

3/10/2022

3/10/2022

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.

DATE

NAME

LEGEND:

5808-A Breckenridge Parkway

Tampa, FL 33610

Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants

MC SQUARED, INC.

KF

KF

T062107.069-G

Cargo Apron Reconstruction and Replacement for Runway 9-27 With a Taxiway

Part 2: Replacement for Runway 9-27 with a Taxiway

St. Pete-Clearwater, Pinellas County, Florida

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Abner M Reis, P.E.

FLORIDA LICENSE No. 93783

ED

AR 4/6/2022

DCP-11EC-2

DCP-12

DCP-10

EC-3

EC-1

Taxiway T

Source: Google Earth

Image Date: 5/23/2021

Graphic Scale (feet)

0' 40'20'

3/10/2022

3/10/2022

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.

DATE

NAME

LEGEND:

5808-A Breckenridge Parkway

Tampa, FL 33610

Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants

MC SQUARED, INC.

KF

KF

Approximate Test Locations

T062107.069-G

Cargo Apron Reconstruction and Replacement for Runway 9-27 With a Taxiway

Part 2: Replacement for Runway 9-27 with a Taxiway

St. Pete-Clearwater, Pinellas County, Florida

4/6/2022

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Abner M Reis, P.E.

FLORIDA LICENSE No. 93783

ED

AR

Boring No. : TB-1

Date : 2/15/2022

Boring No. : TB-2

Date : 2/15/2022

N

Boring No. : TB-3

Date : 2/15/2022

Boring No. : TB-4

Date : 2/15/2022

Boring No. : TB-5

Date : 2/15/2022

Boring No. : TB-6

Date : 2/15/2022

Boring No. : TB-7

Date : 2/15/2022

27 10

Boring Terminated at 10 ft.

4 5 4 4 5

12 12

N N N N N N

Boring Terminated at 10 ft. Boring Terminated at 10 ft. Boring Terminated at 10 ft. Boring Terminated at 10 ft. Boring Terminated at 10 ft. Boring Terminated at 10 ft.

49WOH

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

NMC: 9.2%

-200: 6.7%

NMC: 21.8%

-200: 5.7%

NMC: 19.7%

-200: 6.9%

D E

P T

H

F

E E

T

D E

P T

H

F

E E

T

*N Values Drawn at Top of Interval

LEGEND

GRANULAR MATERIALS- RELATIVE DENSITY

VERY LOOSE

LOOSE

MEDIUM DENSE

DENSE

VERY DENSE

< 4

4-10

10-30

30-50

> 50

SILTS AND CLAYS CONSISTENCY

VERY SOFT

SOFT

FIRM

STIFF

VERY STIFF

HARD

< 2

2-4

4-8

8-15

15-30

> 30

SPT Spoon Inside Diameter 1 3/8"

SPT Spoon Outside Diameter 2"

ASTM Standard Drop Safety Hammer

Average Hammer Drop Height 30"

Hammer Weight 140 lbs

SPT (BLOWS/FT)

SPT (BLOWS/FT)

(SP) Poorly Graded Fine Sand

(SP-SM) Poorly Graded Fine Sand With Silt

(GP) Poorly Graded Gravel

NOTES:

Water Table at Time of Investigation

HA Hand Auger

N SPT N-Value

NMC: 21.5%

-200: 6.9%

Estimated seasonal high groundwater level (SHWT)

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.

DATE

NAME

5808-A Breckenridge Parkway

Tampa, FL 33610

Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants

MC SQUARED, INC.

Subsurface Boring Profiles

KF

KF

3/10/2022

3/10/2022

Cargo Apron Reconstruction and Replacement for Runway 9-27 With a Taxiway

Part 2: Replacement for Runway 9-27 with a Taxiway

St. Pete-Clearwater, Pinellas County, Florida

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Abner M Reis, P.E.

FLORIDA LICENSE No. 93783

ED

AR

T062107.069-G

4/6/2022

*N Values Drawn at Top of Interval

Boring No. : TB-8

Date : 2/15/2022

Boring No. : TB-9

Date : 2/15/2022

N

Boring No. : TB-10

Date : 2/18/2022

Boring No. : TB-11

Date : 2/17/2022

Boring No. : TB-12

Date : 2/15/2022

Boring No. : TB-13

Date : 2/15/2022

Boring No. : TB-14

Date : 2/15/2022

Boring Terminated at 10 ft.

7 8 8 7

N N N N N N

Boring Terminated at 10 ft. Boring Terminated at 10 ft. Boring Terminated at 10 ft. Boring Terminated at 10 ft. Boring Terminated at 10 ft. Boring Terminated at 10 ft.

65976

6 26

D E

P T

H

F

E E

T

D E

P T

H

F

E E

T

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

HA

LEGEND

GRANULAR MATERIALS- RELATIVE DENSITY

VERY LOOSE

LOOSE

MEDIUM DENSE

DENSE

VERY DENSE

< 4

4-10

10-30

30-50

> 50

SILTS AND CLAYS CONSISTENCY

VERY SOFT

SOFT

FIRM

STIFF

VERY STIFF

HARD

< 2

2-4

4-8

8-15

15-30

> 30

SPT Spoon Inside Diameter 1 3/8"

SPT Spoon Outside Diameter 2"

ASTM Standard Drop Safety Hammer

Average Hammer Drop Height 30"

Hammer Weight 140 lbs

SPT (BLOWS/FT)

SPT (BLOWS/FT)

(SP) Poorly Graded Fine Sand

(SP-SM) Poorly Graded Fine Sand With Silt

(GP) Poorly Graded Gravel

NMC: 23.1%

-200: 6.8%

NMC: 22.9%

-200: 6.0%

OC: 1.3%

NMC: 22.5%

-200: 9.9%

NOTES:

Water Table at Time of Investigation

HA Hand Auger

N SPT N-Value

Estimated seasonal high groundwater level (SHWT)

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.

DATE

NAME

5808-A Breckenridge Parkway

Tampa, FL…