24-8265_Exhibit_L-2_-_Geotechnical_Report_Mast_Arm_Signed.pdf

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

State of Florida Registration No. 28073

August 1, 2023

Kisinger Campo & Associates 13461 Parker Commons Blvd, Suite 104 Ft. Myers, FL 33912

Attn: Jesse E. Gill, PE

Project Manager

RE: Structures Geotechnical Report – Mast Arms 16th Street NE Bridge

Collier County, Florida

FPID 451283-1-58-01

TSF Project No. 7511-22-279

Tierra South Florida, Inc. (TSFGeo) has completed the geotechnical study for the subject project. The geotechnical investigation was performed in accordance with FDOT standard design procedures. This report presents the results of our study and includes our evaluation of the soil and groundwater conditions encountered and soil parameters for foundation design.

1.0 PROJECT DESCRIPTION

The project includes approximately 3.3 miles of 16th Street NE from Golden Gate Boulevard to north of Randall Boulevard. The proposed improvements include a new bridge over the Golden Gate Main Canal, roadway widening, a 6-foot sidewalk on the west side of the roadway, drainage improvements, and mast arms at Randall Boulevard.

The purpose of this study was to provide geotechnical (i.e. soils and groundwater) input to the design team to assist in the design and construction of the proposed mast arm foundations at 16th Street NE and Randall Boulevard. The roadway, sidewalk, drainage improvements, and bridge will be addressed under separate cover.

2.0 SCOPE OF SERVICES

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

1. Performed two (2) Standard Penetration Test (SPT) borings to depths of 25 feet.

2. Classified soil samples using the Unified Soil Classification System (USCS).

3. Prepared soil parameters for design of the mast arm foundations (by others).

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

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Structures Geotechnical Report - Mast Arms 2

Collier County, Florida

FPID 451283-1-58-01

TSF Project No. 7511-22-279

3.0 RESULTS OF SUBSURFACE EXPLORATION

The subsurface conditions at the proposed foundation locations were explored by performing two (2) SPT borings to depths of 25 feet below existing grades. Prior to our field exploration, the foundation locations were marked in the field by TSF personnel using a hand-held GPS and utility clearance performed through Sunshine 811.

Representative soil samples collected from the borings were classified and stratified in general accordance with the Unified Soil Classification System (USCS). A Geotechnical Engineer bases soil stratification on a visual review of the recovered samples, 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 profile represents the conditions at that location, variations do occur and should be expected between borings.

The report of core borings which present borehole locations, soil stratification, and the groundwater table depth, if encountered, are provided in the Appendix.

4.0 GROUNDWATER CONDITIONS

The groundwater level was encountered at depths of 2 to 3 feet below existing grades. 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 design for mast arm signals (drilled shafts) assumes the following soil criteria:

Classification: Cohesionless (Fine Sand) Friction Angle: 30° Unit Weight: 50 pcf (assumed submerged) Average N-blow count > or = 15 (mast arms)

The borings meet or exceed the standard design requirements at depths greater than 15 feet. The soil parameters for design are provided in the Appendix. Soil parameters are provided with depth and as a weighted average per depth of shaft.

For foundations 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.

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) or organic soils.

Structures Geotechnical Report - Mast Arms 3

Collier County, Florida

FPID 451283-1-58-01

TSF Project No. 7511-22-279

5.2 Drilled Shaft Construction

Drilled shaft construction for the proposed 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.

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 on the data obtained from the soil borings performed at the location 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.

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

Sincerely, TSFGeo 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 Florida License 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.

APPENDIX: Report of Core Borings, Soil Parameters Table for Foundation Design.

APPENDIX

16th ST. NE

Reference Boring No.:

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 5 6 SP 105 42.6 30

4.00 7 9 SP 105 42.6 30

6.00 7 9 SP 105 42.6 30

8.00 6 7 SP 105 42.6 30

10.00 50 62 SP 125 62.6 34

15.00 33 41 Limestone 135 72.6 38

20.00 39 48 Limestone 135 72.6 38

25.00 50 62 Limestone 135 72.6 38

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) Standard Plans?

Weighted Average (0~10 ft): 15 19 Sand 110 47.6 30 No Weighted Average (0~15 ft): 21 26 Sand 115 52.6 32 Yes Weighted Average (0~20 ft): 26 32 Limestone 135 72.6 36 Yes Weighted Average (0~25 ft): 30 37 Limestone 135 72.6 36 Yes

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.

16th Street NE Collier County, Florida

TSF Project No. 7511-22-279

SOIL PARAMETERS TABLE FOR FOUNDATION DESIGN

MA-01 (NW Quadrant)

Soil Parameters based on Weighted Averages, per Depth of Shaft

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

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.

Reference Boring No.:

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 110 47.6 30

4.00 5 6 SP 105 42.6 30

6.00 5 6 SP 105 42.6 30

8.00 3 4 SP 105 42.6 28

10.00 7 9 SP 105 42.6 30

15.00 17 21 Limestone 125 62.6 34

20.00 37 46 Limestone 135 72.6 38

25.00 33 41 Limestone 135 72.6 38

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) Standard Plans?

Weighted Average (0~10 ft): 6 7 Sand 105 42.6 30 No Weighted Average (0~15 ft): 10 12 Sand 110 47.6 30 No Weighted Average (0~20 ft): 16 20 Limestone 125 62.6 32 Yes Weighted Average (0~25 ft): 20 25 Limestone 125 62.6 34 Yes

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.

16th Street NE Collier County, Florida

TSF Project No. 7511-22-279

SOIL PARAMETERS TABLE FOR FOUNDATION DESIGN

MA-02 (SE Quadrant)

Soil Parameters based on Weighted Averages, per Depth of Shaft

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.