Appendix_6_-_004183M.Geotechnical_Report_54th_and_113th_REV_032822_SS.pdf

6011 Benjamin Road, Suite 106 • Tampa, Florida 33634 813-993-0093 • www.TSFGeo.com

State of Florida Registration No. 28073

Revised March 28, 2022 January 20, 2022

Metric Engineering, Inc.

525 Technology Park, Suite 153 Lake Mary, Florida 32746

Attn: Josh Reichert, P.E.

Traffic Operations Manager

RE: Geotechnical Engineering Services Report

Design Services for 54th Ave. at 113th St. Mast Arm Hardening Pinellas County, Florida County PID: 004183M TSF Project No.: 7511-21-218

Tierra South Florida, Inc. (TSF), Inc. has completed the geotechnical study for the subject project. The geotechnical investigation was performed in general accordance with Pinellas County and FDOT procedures. This report presents the results of our study and includes our evaluation of the soil and groundwater conditions at the proposed mast arm locations, soil parameters for foundation design and existing pavement conditions.

If you have any questions or comments regarding this report, please contact our office at your earliest convenience.

Sincerely, TSF

This document has been digitally signed and sealed by:

Amy L. Guisinger, P.E. Ramakumar Vedula, P.E.

Principal Engineer Principal Engineer FL Registration No. 63989 FL Registration No. 54873 On the date adjacent to the seal.

Printed copies of this document are not considered signed and sealed and the signature must be verified on any electronic copies.

http://www.tsfgeo.com/

Table of Contents

1.0 PROJECT DESCRIPTION

2.0 SCOPE OF SERVICES

3.0 RESULTS OF SUBSURFACE EXPLORATION

3.1 SPT Borings for Mast Arms

3.2 Pavement Cores

4.0 GROUNDWATER CONDITIONS

5.0 ENGINEERING EVALUATIONS AND RECOMMENDATIONS

5.1 Foundation Design

5.2 Pavement Design Considerations

6.0 REPORT LIMITATIONS

APPENDIX: Boring Location Plan and Soil Profiles Recommended Soil Parameters for Foundation Design Pavement Core Location Plan Pavement and Base Material Data Sheet Pavement Core Photos

Geotechnical Engineering Service Report 1

Pinellas County, Florida County PID: 004183M TSF Project No.: 7511-21-218

Revised March 28, 2022

1.0 PROJECT DESCRIPTION

The project consists of new Mast Arms Signal structures at the intersection of 54th Avenue and 113th Street in Pinellas County, Florida. This report presents the results of our geotechnical exploration and recommendations for design and construction of the proposed mast arm foundations and information on existing pavement conditions.

2.0 SCOPE OF SERVICES

The study was performed to obtain information on the existing subsurface conditions at the proposed mast arm locations, and existing pavement conditions, to assist in the design and preparation of construction plans. The following services were provided:

1. Performed three (3) Standard Penetration Test (SPT) borings to depths of 30 feet below existing grades.

2. Visually classified and stratified the samples in the laboratory using the Unified Soil

Classification System (USCS).

3. Performed four (4) asphalt cores.

4. Prepared this geotechnical engineering report summarizing the field and laboratory data, subsurface conditions encountered, and the geotechnical recommendations for the proposed foundations.

3.0 RESULTS OF SUBSURFACE EXPLORATION

The subsurface conditions at the proposed mast arm foundation locations were explored by performing three (3) SPT borings to depths of 30 feet below existing grades. In addition, TSF performed four (4) pavement cores to provide information on the existing pavement section. Prior to our field exploration, the proposed test locations were marked in the field by TSF personnel using a hand-held GPS, utility clearance performed through Sunshine 811 and Pinellas County right-of-way use permit obtained.

3.1 SPT Borings for Mast Arms

Representative soil samples collected from the borings were classified and stratified in general accordance with Unified Soil Classification System (USCS). 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

Geotechnical Engineering Service Report 2

Pinellas County, Florida County PID: 004183M TSF Project No.: 7511-21-218

Revised March 28, 2022 abbreviated or omitted for clarity. The boring profile represents the conditions at that location, variations do occur and should be expected between borings.

The boring location plan and soil profiles which present borehole locations, soil stratification and groundwater table depth, if encountered, are provided in the Appendix.

3.2 Pavement Cores

The pavement cores were obtained at locations approved by the project designer. Right-of-way use permits were obtained from Pinellas County. Maintenance-of-traffic was performed in general accordance with FDOT Standard Plans. The approximate locations of the pavement cores are depicted on the attached Coring Location Plan. Core samples were returned to our laboratory and reviewed for asphalt, base and stabilized subgrade information. A summary of the core data is attached as the Pavement Evaluation Coring and Condition Data sheet. Photos of the pavement core locations, in the field, and pavement cores, in the laboratory, are attached as Core Photos.

4.0 GROUNDWATER CONDITIONS

The groundwater level was measured at each boring location following the termination of drilling. The groundwater table was encountered at depths of 3 to 4 feet below existing ground surface. The groundwater table information at each boring location is presented on the soil profiles in the 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, underdrains 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 procedures.

5.0 ENGINEERING EVALUATIONS AND RECOMMENDATIONS

5.1 Foundation Design

The FDOT Standard foundation (Drilled Shaft) design for Mast Arms are based on the following soil criteria:

Classification: Cohesionless (Fine Sand) Friction Angle: 30 Degrees Unit Weight: 50 pcf (assumed submerged) N-blowcount: 15

Geotechnical Engineering Service Report 3

Pinellas County, Florida County PID: 004183M TSF Project No.: 7511-21-218

Revised March 28, 2022

In general, the recommended design soil parameters from the boring data are less than the above standard design assumptions. The Soil Parameters Table for Foundation Design is provided in the Appendix.

For shafts adjacent to sloping ground, include the portion of the shaft with less than 2.5D soil cover (face-of-shaft to face-of-slope) in the unsupported length, and design the portion of the shaft with more than 2.5D soil cover as though founded on level ground.

Also, due to the potential of instability during construction and potential excessive settlements after construction, foundations should not be tipped or embedded within 1D above very loose or very soft soil zones (NAuto< 2).

Drilled shaft construction for the proposed mast arm structures should be performed in accordance with Section 455 of the most recent edition of the FDOT Standard Specifications for Road and Bridge Construction. The sandy soils below the groundwater level will tend to cave during construction. Therefore, in addition to the upper temporary casing, it is likely drilling slurry will be required to maintain the stability of the excavation.

5.2 Pavement Design Considerations

We anticipate that the proposed pavement structure will be a semi-flexible asphaltic concrete section. Soils existing along most of the project alignment should have adequate subgrade strength for pavement support.

For a stabilized subgrade, we recommend a sand-gravel mixture, 12-inch-thick, with a minimum design LBR of 40. Base course should consist of limerock, shellrock or coquina, meeting the minimum requirements of the FDOT “Standard Specifications for Road and Bridge Construction,” Sections 911, 913 or 915, respectively. Limerock base 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).

Asphalt thickness should be determined considering the anticipated traffic loading conditions and expected life expectancy of the pavement section.

6.0 REPORT LIMITATIONS

Our professional services have been performed, our findings obtained, and our recommendations prepared in accordance with generally accepted geotechnical engineering principles and practices. This company is not responsible for the conclusions, opinions, or recommendations made by others based on this data.

The scope of the investigation was intended to evaluate soil conditions within the influence zone of the foundations. The analysis and recommendations submitted in this report are based upon the data obtained from the soil boring performed at the location

Geotechnical Engineering Service Report 4

Pinellas County, Florida County PID: 004183M TSF Project No.: 7511-21-218

Revised March 28, 2022 indicated. If any subsoil variations become evident during this project, a re-evaluation of the recommendations contained in this report will be necessary after we have had an opportunity to observe the characteristics of the conditions encountered. The applicability of the report should also be reviewed in the event significant changes occur in the design, nature, or location of the proposed structure.

The scope of our services does not include any environmental assessment or investigation for the presence or absence of hazardous or toxic materials in the soil, groundwater, or surface water within or beyond the site studied. Any statements in this report regarding odors, staining of soils, or other unusual conditions observed are strictly for the information of our client.

The geotechnical engineer warrants that the findings, recommendations, specifications, or professional advice contained herein have been made in accordance with generally accepted professional geotechnical engineering practices in the local area. No other warranties are implied or expressed.

APPENDIX

Boring Location Plan and Soil Profiles Recommended Soil Parameters for Foundation Design

Structure Location/Information Mast Arm

B-01 (Mast Arm 1)

STA. 55+45, 71' RT

12/02/2021

Depth (ft) N-value (Automatic Hammer)

N-Value (Equivalent Safety

Hammer) Soil Type Approx. Unit

Weight (pcf)

Approx.

Submerged Unit

Weight (pcf)

Soil Angle of Friction (Degrees)

2.00 4 5 SP/SP-SM 107 45 29

4.00 21 26 SP/SP-SM 117 55 32

6.00 9 11 SP/SP-SM 112 50 30

8.00 8 10 SP/SP-SM 112 50 30

10.00 9 11 SP/SP-SM 112 50 30

15.00 3 4 SM 102 40 28

20.00 7 9 SM 107 45 29

25.00 12 15 SM 112 50 30

30.00 7 9 SC 107 45 29

35.00 7 9 CL 117 55 29

Note - N-Value for 2 ft adjusted to consider compacted base and concrete foundation at the boring location.

Depth (ft) N-value (Automatic Hammer)

N-Value (Equivalent Safety

Hammer)

Soil Type Modelled As

Approx. Unit Weight (pcf)

Approx.

Submerged Unit

Weight (pcf)

Soil Angle of Friction (Degrees)

Weighted Average (0~5 ft): 13 16 Sand 112 50 30 Weighted Average (0~10 ft): 10 12 Sand 112 50 30 Weighted Average (0~15 ft): 8 10 Sand 112 50 30 Weighted Average (0~20 ft): 8 10 Sand 112 50 30 Weighted Average (0~25 ft): 8 10 Sand 112 50 30 Weighted Average (0~30 ft): 8 10 Sand 112 50 30 Weighted Average (0~35 ft): 8 10 Sand 117 55 30

Note 3: If the foundation is located on or near a slope, ignore the horizonal soil support where soil cover is 2.5 times the pile diameter or less.

54TH AVE AND 113TH ST. MAST ARMS

PINELLAS COUNTY, FLORIDA

167-0005-CN TASK 4; TSF PROJECT NO. 7511-21-218

SOIL PARAMETERS TABLE FOR FOUNDATION DESIGN

Soil Parameters based on Weighted Averages, per Depth of Shaft

* If a boring encountered organic soils at near surface depths (i.e. topsoil), the Boring Top Elevation is the top of the sandy soil or limestone layers immediately below surficial layer. Otherwise, the value is the top of the reference boring.

Note 1: The Weighted Average N-Value for various depths has been converted to equivalent N-Value of safety hammer if a automatic hammer was used.

Note 2: Submerged condition should be considered in the foundation design.

B-02 (Mast Arm 2)

STA. 54+56, 68' LT

11/30/2021

Depth (ft) N-value (Automatic Hammer)

N-Value (Equivalent Safety

Hammer) Soil Type Approx. Unit

Weight (pcf)

Approx.

Submerged Unit

Weight (pcf)

Soil Angle of Friction (Degrees)

2.00 9 11 SP/SP-SM 112 50 30

4.00 6 7 SP/SP-SM 107 45 29

6.00 6 7 SP/SP-SM 107 45 29

8.00 12 15 SP/SP-SM 112 50 30

10.00 12 15 SM 112 50 30

15.00 9 11 SP-SM 112 50 30

20.00 17 21 SP-SM 117 55 32

25.00 7 9 CL 117 55 29

30.00 7 9 CL 117 55 29

Note - N-Value for 2 ft adjusted to consider compacted base and concrete foundation at the boring location.

Depth (ft) N-value (Automatic Hammer)

N-Value (Equivalent Safety

Hammer)

Soil Type Modelled As

Approx. Unit Weight (pcf)

Approx.

Submerged Unit

Weight (pcf)

Soil Angle of Friction (Degrees)

Weighted Average (0~5 ft): 8 10 Sand 112 50 30 Weighted Average (0~10 ft): 9 11 Sand 112 50 30 Weighted Average (0~15 ft): 9 11 Sand 112 50 30 Weighted Average (0~20 ft): 11 14 Sand 112 50 30 Weighted Average (0~25 ft): 10 12 Sand 117 55 30 Weighted Average (0~30 ft): 10 12 Sand 117 55 30

Note 3: If the foundation is located on or near a slope, ignore the horizonal soil support where soil cover is 2.5 times the pile diameter or less.

54TH AVE AND 113TH ST. MAST ARMS

PINELLAS COUNTY, FLORIDA

167-0005-CN TASK 4; TSF PROJECT NO. 7511-21-218

SOIL PARAMETERS TABLE FOR FOUNDATION DESIGN

Soil Parameters based on Weighted Averages, per Depth of Shaft

* If a boring encountered organic soils at near surface depths (i.e. topsoil), the Boring Top Elevation is the top of the sandy soil or limestone layers immediately below surficial layer. Otherwise, the value is the top of the reference boring.

Note 1: The Weighted Average N-Value for various depths has been converted to equivalent N-Value of safety hammer

B-03 (Mast Arm 3)

STA. 55+30, 72' LT

03/15/2022

Depth (ft) N-value (Automatic Hammer)

N-Value (Equivalent Safety

Hammer) Soil Type Approx. Unit

Weight (pcf)

Approx.

Submerged Unit

Weight (pcf)

Soil Angle of Friction (Degrees)

2.00 7 SP/SP-SM 107 45 29

4.00 7 SP/SP-SM 107 45 29

6.00 9 SP/SP-SM 107 45 29

8.00 5 SP/SP-SM 107 45 29

10.00 7 SM 107 45 29

15.00 10 SM 112 50 30

20.00 22 SM/SP-SM 117 55 32

25.00 9 SC 117 55 29

30.00 14 CL 117 55 30

Note - N-Value for 2 ft adjusted to consider compacted base and concrete foundation at the boring location.

Depth (ft) N-value (Automatic Hammer)

N-Value (Equivalent Safety

Hammer)

Soil Type Modelled As

Approx. Unit Weight (pcf)

Approx.

Submerged Unit

Weight (pcf)

Soil Angle of Friction (Degrees)

Weighted Average (0~5 ft): 7 7 Sand 107 45 29 Weighted Average (0~10 ft): 7 7 Sand 107 45 29 Weighted Average (0~15 ft): 8 8 Sand 107 45 29 Weighted Average (0~20 ft): 12 12 Sand 112 50 30 Weighted Average (0~25 ft): 11 11 Sand 117 55 30 Weighted Average (0~30 ft): 12 12 Sand 117 55 30

Note 3: If the foundation is located on or near a slope, ignore the horizonal soil support where soil cover is 2.5 times the pile diameter or less.

54TH AVE AND 113TH ST. MAST ARMS

PINELLAS COUNTY, FLORIDA

167-0005-CN TASK 4; TSF PROJECT NO. 7511-21-218

SOIL PARAMETERS TABLE FOR FOUNDATION DESIGN

Soil Parameters based on Weighted Averages, per Depth of Shaft

* If a boring encountered organic soils at near surface depths (i.e. topsoil), the Boring Top Elevation is the top of the sandy soil or limestone layers immediately below surficial layer. Otherwise, the value is the top of the reference boring.

Note 1: The Weighted Average N-Value for various depths has been converted to equivalent N-Value of safety hammer

Pavement Core Location Plan Pavement and Base Material Data Sheet

Pavement Core Photos

113th St and 54th Ave Pavement Cores

Legend

Pavement Core Location

200 ft

N

N

Layer

Layer

Layer

Layer

Depth (in.)

27.8214470 -82.7956160 PC-01 1/6/2022 2 1.0 1.3 2.3 4.0 Yes 2.3 Poor 0.1 5.5 Out R1 Eastbound

27.8212040 -82.7952330 PC-02 1/6/2022 2 2.0 1.5 3.5 4.0 Yes - Good 3.0 Out R4 Northbound

27.8215890 -82.7950950 PC-03 1/6/2022 2 1.6 1.4 3.0 7.0 Yes - Fair 3.8 Out R2 Turn-Lane onto 113th St

27.8220680 -82.7954390 PC-04 1/6/2022 2 1.8 2.0 3.8 8.5 Yes 1.5 Fair 0.1 1.9 Out L4 Southbound

Note - Latitude and Longitude are approximate

Pavement Conditions:

Pavement conditions based on visual observations only

54th Ave & 113th St Pinellas County, Florida

7511-21-218

Number of Layers Estimated

Pavement Layers (in.) Total Core

Length (in.)

NotesCrack * Pavement Condition

Rut Depth (in.)

Cross Slope

Cross Slope

Direction

Pavement and Base Material Data Sheet

Latitude Longitude Core ID Core Date

Base Material

Limerock Thickness (in.)

Stabilized Subgrade

Core Photos 54th Ave. 113th St.

TSF Project No. 7511-21-218

Core ID PC-01 Core Date 1/6/2022

Lane R1 Core in Wheel Path? Yes

Lattitude 27.821447 Longitude -82.795616

TSF Project No. 7511-21-218

Core ID PC-02 Core Date 1/6/2022

Lane R4 Core in Wheel Path? Yes

Lattitude 27.821204 Longitude -82.795233

TSF Project No. 7511-21-218

Core ID PC-03 Core Date 1/6/2022

Lane R2 OR Core in Wheel Path? Yes

Lattitude 27.821589 Longitude -82.795095

TSF Project No. 7511-21-218

Core ID PC-04 Core Date 1/6/2022

Lane L4 Core in Wheel Path? Yes

Lattitude 27.822068 Longitude -82.795439