REPORT OF GEOTECHNICAL ENGINEERING SERVICES

PROPOSED CULVERT REPLACEMENT

303 4TH AVENUE SE

CULVERT REPLACEMENT

RUSKIN, HILLSBOROUGH COUNTY, FLORIDA

HILLSBOROUGH COUNTY CIP NO. 46142-490

ANTICUS PROJECT NO.: 01.5482-3.22

Prepared for:

PLUMMER | WATERMARK ENGINEERING GROUP, INC.

3868 SUN CITY CENTER BOULEVARD

SUN CITY CENTER, FLORIDA 33573

Prepared by:

P.O. Box 921 Riverview, Florida 33568

Time Honored Experience. Progressive Ingenuity.

P.O. Box 921 Riverview, Florida 33568 – Main Office/Facsimilie 813.642.3965

February 20, 2023

Plummer | Watermark Engineering Group, Inc.

3866 Sun City Center Blvd.

Sun City Center, Florida 33573

Attention: Mark J. Flint, P.E., Integrated Water Team Leader

Subject: Report of Geotechnical Engineering Services 303 4th Avenue SE Culvert Replacement Ruskin, Hillsborough County, Florida Hillsborough County CIP No. 46142-490

Anticus Project No: 01.5482-3.22

Dear Mr. Flint:

Anticus Engineering, LLC (Anticus) has completed a geotechnical exploration for the above referenced project, and we are submitting our findings in this report. We conducted this project in general accordance with our Letter of Commitment No. 01.5482-3.22, dated August 12, 2022.

This report explains our understanding of the project, provides a description of the site and subsurface conditions encountered, and presents our recommendations regarding the site preparation and recommendations.

Anticus appreciates the opportunity to be of service to you. We look forward to helping you through project completion. Please contact us if you have any questions.

Respectfully submitted, Anticus Engineering, LLC P.O. Box 921 Riverview, Florida 33568

J. Wesley Parker, P.E. Jeanne Berg, P.E.

Project Manager FL License No. 50699

This item has been electronically signed and sealed by Jeanne Berg, P.E. on February 20, 2023 using a Digital Signature. Printed copies of this document are not considered signed and sealed and the signature must be verified on any electronic copies.

TABLE OF CONTENTS

i

1.0 INTRODUCTION

1.1 GENERAL DISCUSSION

2.0 SITE INFORMATION

2.1 SOIL SURVEY INFORMATION

3.0 EXPLORATION AND TESTING METHODS

3.1 FIELD EXPLORATION AND TESTING

3.2 LABORATORY TESTING

4.0 SUBSURFACE CONDITIONS

4.1 GENERAL SOIL PROFILE

4.2 GROUND WATER

4.3 TYPICAL SEASONAL HIGH WATER TABLE

5.0 CONCLUSIONS

6.0 RECOMMENDATIONS

7.0 LIMITATIONS OF REPORT

APPENDIX

Table 1 Summary of Laboratory Test Results Report of Core Boring Sheet

REPORT OF SUBSURFACE EXPLORATION

303 4TH AVENUE SE

CULVERT REPLACEMENT

RUSKIN, HILLSBOROUGH COUNTY, FLORIDA

HILLSBOROUGH COUNTY CIP NO. 46142-490

ANTICUS PROJECT NO. 01.5482-3.22

1.0 INTRODUCTION

1.1 GENERAL DISCUSSION

Anticus conducted a subsurface exploration for the proposed culvert replacement located near

303 4th Avenue SE in Ruskin, Hillsborough County, Florida. We provided our services in general accordance with our Letter of Commitment No. 01.5482-3.22, dated August 12, 2022.

The purpose of the exploration was to evaluate subsurface conditions for the proposed construction and to provide geotechnical engineering recommendations regarding site preparation and earthwork procedures at the location of the proposed improvements. This report presents a brief discussion of our understanding of the project, the exploration procedures and results, and our conclusions and recommendations regarding the above considerations. This report addresses the subsurface conditions at the location of the proposed and referenced drainage structure replacement only.

2.0 SITE INFORMATION

2.1 SOIL SURVEY INFORMATION

According to the Soil Survey of Hillsborough County, Florida, prepared by the U.S. Department of Agriculture Natural Resource Conservation Service (NRCS, formerly the Soil Conservation

Service), the subject property is primarily underlain by Wabasso-Urban land complex (Unit 58).

The general soil description as described in the Soil Survey is presented in the following table.

SUMMARY OF USDA SOIL SURVEY

HILLSBOROUGH COUNTY, FLORIDA

USDA Map Symbol and Soil Name

Depth (in)

Soil Classification

Permeability (in/hr) pH

Seasonal High Water Table

Risk of Corrosion

USCS AASHTO

Depth (feet)

Months Uncoated

Steel Concrete

(58) Wabasso-

Urban Land

0-5 SP, SP-SM A-3 6.0 - 20.0 3.5-6.5

0.5-1.5 June-Sept Moderate High

5-21 SP, SP-SM A-3 6.0 - 20.0 3.5-6.5

21-31 SM, SP-SM A-2-4, A-3 0.6 - 2.0 3.5-6.5

31-37 SP, SP-SM A-3 6.0 - 20.0 5.1-8.4

37-48 SC, SC-SM A-2-4, A-2-6 0.1 - 0.2 5.1-8.4

48-80 SM, SP-SM A-2-4, A-3 6.0 - 20.0 7.4-8.4

Report of Geotechnical Engineering Services February 20, 2023 CIP: 46142-490 Anticus Project No. 01.5482-3.22

It should be noted that information contained in the USDA Soil Survey may not be reflective of current subsurface conditions, particularly if recent development in the project vicinity (which includes man-made ditches, earthwork and water features) has modified existing soils or surface/subsurface drainage.

3.0 EXPLORATION AND TESTING METHODS

One (1) Cone Penetration Test (CPT) boring was advanced with a tractor-mounted rig - at the locations shown on the attached Field Test Location Plan. The CPT boring was performed virtually continuously to the boring termination depth noted on the Soil Profile. The CPT soil data was empirically correlated into Standard Penetration Test (SPT) Standard Penetration

Resistance Values (N60) and soil type in general accordance with the Unified Soil Classification

System (USCS). The SPT N60 values are used to establish settlement/consolidation characteristics of the soil profiles.

The SPT field test procedure, entitled "Standard Method for Penetration Test and Split-Barrel

Sampling of Soils” includes drilling the bore hole to the required depth and cleaning the bore hole; followed by driving the sampler (2" O.D.) 18 or 24 inches into the undisturbed soil by a

140-pound drop-hammer falling 30 inches; the number of blows required to drive the sampler the second and third 6-inch increments is known as the Standard Penetration Resistance (N60).

The procedures used by Anticus for field sampling and testing are in general accordance with

ASTM procedures and established engineering practice.

3.1 FIELD EXPLORATION AND TESTING

One (1) CPT boring was advanced to an approximate depth of 15 feet below the existing ground surface. The drillers advanced the boring using wet rotary methods and collected soil samples using a split-barrel sampler driven by a cathead hammer system according to ASTM D1586.

The boring location was located using hand-held Global Positioning System (GPS) equipment and cloth measuring tape and therefore the location shown on the Field Test Location Plan on the attached Report of Core Boring Sheet should be considered as approximate.

The Soil Profile on the attached Report of Core Boring Sheet, represents our interpretation of the conditions encountered at the boring location. The stratification lines indicated on the Soil

Profile represent the approximate boundaries between soil types; however these transitions may be more gradual than indicated.

3.2 LABORATORY TESTING

Our field representative sealed and returned the soil samples to our office where a Geotechnical

Engineer visually classified the soils in accordance with ASTM D2488, entitled “Standard

Practice for Description and Identification of Soils (Visual-Manual Procedures)” (ASTM D2488) and the American Association of State Highway and Transportation Officials (AASHTO) Soil

Classification System. Soil classification was based on visual observations with the results of the laboratory testing used to confirm the visual classification. Laboratory testing was completed in accordance with applicable Florida Method (FM) or ASTM International (ASTM) methods.

Laboratory classification tests included the following:

• two (2) moisture content tests in accordance with ASTM D2216, entitled “Standard Test

Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by

Mass”;

• two (2) no. 200 sieve wash tests in accordance with ASTM D1140 entitled “Standard

Test Methods for Determining the Amount of Material Finer than the 75-μm (No. 200)

Sieve in Soils by Washing”;

• one (1) particle-size distribution in accordance with ASTM D6913 entitled “Standard Test

Methods for Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis”;

Based on the results of the laboratory testing, the soils tested were classified in accordance with

ASTM D2487, entitled “Standard Practice for Classification of Soils for Engineering Purposes

(Unified Soil Classification System)” and the AASHTO Soil Classification System. A summary of our laboratory testing results is presented on the attached Table 1 and attached Report of

Core Borings Sheet.

4.0 SUBSURFACE CONDITIONS

4.1 GENERAL SOIL PROFILE

Detailed descriptions are presented on the attached soil profile. When reviewing the soil profile, the indicated boundaries between soil strata are approximate and the transitions between strata are typically more gradual. Also, variations in subsurface conditions from those encountered may exist between the boring locations.

4.2 GROUNDWATER

The groundwater level was encountered in the CPT boring at 3 feet below existing grade at the time of field exploration.

Groundwater levels fluctuate with time due to seasonal moisture changes, tidal influences and locally heavy precipitation events. Therefore, future ground water levels may be encountered at depths different from those identified in our borings.

4.3 TYPICAL SEASONAL HIGH WATER TABLE

The SHGWT is typically encountered during late summer following the rainy season. Several factors affect the seasonal high water table including tidal influences, the amount of rainfall; the drainage characteristics of the soils; the land surface elevation; relief points such as lakes, rivers or swamps; and distance to relief points. Based on published information the estimated current SHGWT is estimated to be 0.5 feet below existing grade. A SHGWT hand auger was not completed during our field services. If a more specific SHGWT estimate is necessary, we can retained to complete additional field services to evaluate the SHGWT further.

5.0 CONCLUSIONS

We base the following conclusions in part on the preceding project information and the results of the subsurface exploration. The following describes our conclusions concerning geotechnical issues associated with the project:

The proposed drainage structure can be supported by the subsurface soils designed as noted below and assuming that proper site preparation is completed as described in subsequent paragraphs.

The SHGWT table is estimated to be near existing grade. De-watering may be required during replacement of the drainage structure, especially if the construction is performed during the rainy season.

6.0 RECOMMENDATIONS

To prepare the site for construction, including removal of the 43 inch by 68 inch corrugated metal pipe (CMP) and replacement with 43 inch by 68 inch reinforced concrete pipe (RCP), work shall be completed in accordance with the Florida Department of Transportation (FDOT)

Standard Specifications for Road and Bridge Construction (SSRBC) current edition as well as current Hillsborough County Public Works Standard Specifications for Construction requirements (HC PWSSC). Based on the FDOT SSRBC July 2022 edition and the HC

PWSSC October 2017 edition, specifications including FDOT Section 125 Excavation For

Structures and Pipe and Section 430 Pipe Culverts must be followed, with HC PWSSC indicating that “For rigid concrete pipe installation, the County waives the requirement for the laser profiling and measurement technology. The County reserves the right to implement this requirement if the submitted video report indicates a visibly substantial deviation in the joints or alignment of the culvert. The laser profiling and measurement technology will still be required for all other optional culvert material types”.

In general and in summary, based on the FDOT SSRBC July 2022 edition Section 125-8.1.6.1 and our completed borings/probes:

• The upper approximate 6 feet of the soil profile (to approximately 11 feet below existing roadway grade) meets the Group 1 definition of A-3, A-2-4 (with less than 15% fines);

• The material from approximately 11 to 12.5 feet of the soil profile meets the Group 2 definition of A-2-6 material;

The contractor should be aware that variations of the soil profile may exist intermediate of our boring and prepare accordingly.

Scour geometry can be calculated utilizing methods found in the Federal Highway

Administration publication Hydraulic Design of Energy Dissipators for Culverts and Channels in

Hydraulic Engineering Circular No. 14, Third Edition (Publication No. FHWA-NHI-06-086).

Based on the encountered soils at the boring location, a material standard deviation of the cohesionless soils is included in the calculation, which is a factor of D84 and D16 (effective grain size in millimeters of soil in the 84th and 16th percentile, respectively). Based on our sieve analysis, the following values can be used:

Particle Size Coefficient

Grain Size (mm)

D84 0.40

D16 0.075

In Federal Register, Volume 54, No. 209 (October 1989), the United States Department of

Labor, Occupational Safety and Health Administration (OSHA) amended its “Construction

Standards for Excavations, 29 CFR, Part 1926, Subpart P”. This document was issued to better insure the safety of workmen entering trenches or excavations. It is mandated by this federal regulation that excavations, whether they be utility trenches, basement excavations or foundation excavations, be constructed in accordance with the new OSHA guidelines. It is our understanding that these regulations are being strictly enforced and if they are not closely followed, the owner and the contractor could be liable for substantial penalties.

The contractor is solely responsible for designing and constructing stable, temporary excavations and should shore, slope, or bench the sides of the excavations as required to maintain stability of both the excavation sides and bottom. The contractors “responsible persons”, as defined in 29 CFR Part 1926, should evaluate the soil exposed in the excavations as part of the contractor’s safety procedures. In no case should slope height, slope inclination, or excavation depth, including utility trench excavation depth, exceed those specified in all local, state, and federal safety regulations.

We are providing this information solely as a service to our client. Anticus Engineering, LLC does not assume responsibility for construction site safety or the contractor’s or other party’s compliance with local, state, and federal safety or other regulations.

7.0 LIMITATIONS OF REPORT

This report has been prepared for the exclusive use of Plummer | Watermark Engineering

Group, Inc. and Hillsborough County and their designers for specific application to the project previously discussed. Our conclusions and recommendations have been prepared using generally accepted standards of geotechnical engineering and engineering geology practice in the State of Florida. No other warranty is expressed or implied.

Our conclusions and recommendations are based on the design information furnished to us, the data obtained from the previously described exploration and our experience. They do not necessarily reflect variations in the subsurface conditions, which are likely to exist intermediate of our borings and in unexplored areas of the site due to the inherent variability of the subsurface conditions in this geologic region as well as past land use. Should such variations become apparent during construction, it will be necessary to re-evaluate our conclusions and recommendations based upon on-site observation of the conditions.

If changes are made in the overall design or location of the replacement drainage structure, then the recommendations presented in this report may no longer be valid. In such cases, our firm should review the proposed changes to evaluate whether our recommendations need to be modified. The results of this review should be provided in writing. We also request the opportunity to review the applicable portions of the project specifications when the design is finalized. This review will allow us to check whether these documents are consistent with the intent of our recommendations.

Sampling and testing of the soil, rock, ground water, surface water and air for the presence of environmental contamination was beyond the scope of this exploration. We will be glad to provide these services at your request.

The site is underlain by limestone bedrock that is susceptible to dissolution and the subsequent development of karst features such as voids and sinkholes in the natural soil overburden.

Construction in a sinkhole prone area is therefore accompanied by some risk that internal soil erosion and ground subsidence could affect new structures in the future. It is not possible to investigate or design to completely eliminate the possibility of future sinkhole related problems.

In any event, the Owner must understand and accept this risk.

Table 1. Summary of Laboratory Test Results

Boring

No.

Depth

(ft)

Summary of Laboratory Testing

USCS/AASHTO

Classification

Moisture

Content

No. 4

Sieve

No. 8

Sieve

No. 16

Sieve

No. 30

Sieve

No. 50

Sieve

No. 100

Sieve

No. 200

Sieve

B-1 0-4 14 96 95 94 92 76 43 9 SP-SM/A-3

B-1 0.0-0.5 11 - - - - - - 9 SP-SM/A-3

B-1 3.0-3.5 19 - - - - - - 2 SP/A-3

Note:” – “ indicates testing not performed.