Appendix_6-Geotech_Report.pdf

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

MC Squared, Inc.

Geotechnical Engineering Services Report

Mast Arm Hardening – 3 Intersections West Bay Dr. & Indian Rocks Rd., Seminole Blvd & 126th Ave., and East Bay Dr. & US 19 Pinellas County, Florida

Prepared for: Cardno, Inc.

3905 Crescent Park Drive.

Riverview, Florida 33578

Prepared by: MC Squared, Inc.

5808-A Breckenridge Parkway Tampa, Florida 33610

Project No. T022112.019 April 28, 2022

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

April 28, 2022

Mr. Mark Modjeski, PE Traffic Operations Cardno 3905 Crescent Park Drive Riverview, Florida 33578

Subject: Geotechnical Engineering Services Report

Mast Arm Hardening – 3 Intersections – West Bay Dr. & Indian Rocks Rd., Seminole Blvd.

& 126th Ave., and East Bay Dr. & US 19 Pinellas County, Florida

MC2 Project No. T022112.019

Dear Mr. Modjeski :

As requested and authorized by Cardno, Inc. (Cardno), MC Squared, Inc. (MC2) has completed the subsurface soil exploration program for the subject project. The purpose of this program was to evaluate the general subsurface conditions for mast arms proposed at three intersections across Pinellas County, Florida.

This report documents our findings and conclusions. It has been prepared for the exclusive use of Cardno and Pinellas County for specific application to the subject project in accordance with generally accepted geotechnical engineering practices. No other warranty, express or implied, is made.

We appreciate the opportunity to be of service to you on this project. Should you have any questions or require further information, please do not hesitate to contact us.

Respectfully submitted, MC2

Sergio Gomez. Maziar Foroutan, Ph.D.

Staff Engineer Geotechnical Engineer

Ethan Drew, P.E. Prashanth Vaddu, P.E.

Project Engineer Sr. Vice President Florida P.E. No. 75144

West Bay Dr. & Indian Rocks Rd., Seminole Blvd. & 126th Ave., and East Bay Dr. & US 19

MC2 Project No. T022112.019 i

TABLE OF CONTENTS

1 PROJECT OBJECTIVE AND SITE DESCRIPTION

2 SCOPE

3 REVIEW OF AVAILABLE DATA

3.1 Soil Survey Maps

3.2 U.S.G.S Quadrangle Maps

4 FIELD EXPLORATION PROGRAM

5 LABORATORY TESTING PROGRAM

6 GENERAL SUBSURFACE CONDITIONS

7 ANALYSIS AND RECOMMENDATIONS

8 REPORT LIMITATIONS

APPENDIX

Table 1 – Summary of Laboratory Results Table 2 – Summary of Corrosion Series Testing Table 3 through Table 5 – Soil parameters Sheet 1 – USGS Topographic Map Sheet 2A – USDA Soil Survey (West Bay Dr and Indian Rocks Rd) Sheet 2B – USDA Soil Survey (126th Ave and Seminole Blvd) Sheet 2C – USDA Soil Survey (East Bay Dr and US Hwy 19 N) Sheet 3 – Report of Core Borings (West Bay Dr and Indian Rocks Rd) Sheet 4 – Report of Core Borings (126th Ave and Seminole Blvd) Sheet 5 – Report of Core Borings (East Bay Dr and US Hwy 19 N) Test Procedures Important Information About this Geotechnical-Engineering Report and East Bay Dr. & US 19

1 PROJECT OBJECTIVE AND SITE DESCRIPTION

New mast arms are proposed at three intersections in Pinellas County, Florida. Based on our understanding, Pinellas County plans to improve three (3) signalized road intersections by constructing mast arms to replace existing strain poles. Cardno is designing the intersection improvements and selecting the locations of mast arms.

The road intersections that are planned to be improved are:

1) West Bay Dr. & Indian Rocks Rd.

2) Seminole Blvd. & 126th Ave.

3) East Bay Dr. & US 19.

The approximate site location is shown superimposed on a portion of the Clearwater and Safety Harbor, Florida U.S.G.S. quadrangle map presented on Sheet No. 1 in the Appendix.

2 SCOPE

To achieve the project objective, the following scope of services was completed in accordance with our proposal dated February 22, 2021:

1. Reviewed readily available/published data from Soil Survey and Topographic Maps.

2. Coordinated the required permitting (MOT & utility locates) and access to test boring locations.

3. Conducted nine (9) Standard Penetration Test (SPT) borings to determine the nature and condition of the subsurface soils as follows:

• West Bay Dr & Indian Rocks Rd – Four (4) borings

• 126th Ave and Seminole Blvd – Three (3) borings

• East Bay Dr and US Hwy 19 N – Two (2) borings

4. Visually classified all soil samples retrieved from the field followed by laboratory tests on selected representative soil samples.

5. Analyzed the subsurface conditions with regards to the foundation design of the mast arms.

6. Prepared this report to document the results of our field exploration, engineering analysis, and our recommended soil parameters for foundation design.

and East Bay Dr. & US 19

3 REVIEW OF AVAILABLE DATA

3.1 Soil Survey Maps

Based on the Web Soil Survey for Pinellas County, Florida, as prepared by the U.S. Department of Agriculture Soil Conservations Services, seven soil types exist along the project alignment. The Soil Survey identified three major soil types at the mast arm locations, which are described below.

• Astatula soils and Urban land, 0 to 5 percent slopes (4), has a parent material of eolian or sandy marine deposits and a typical profile of fine sand from zero to 80-in. bgs (classified as AASHTO A- 3). The material is excessively drained and has a very high capacity to transmit water. The depth of the groundwater table is more than 80 inches.

• Myakka soils and Urban land (17) has a parent material of sandy marine deposits and a typical profile of fine sand from zero to 80-in. bgs (classified as AASHTO A-3). The material is poorly drained and has a moderately high to high capacity to transmit water. The depth of the groundwater table is about 6 to 18 inches.

• Urban land, 0 to 2 percent slopes (30), are soils in areas of high population density in the largely built environment. These soils can be significantly changed human-transported materials, human-altered materials, or minimally altered or intact “native” soils. Soils in urban areas exhibit a wide variety of conditions and properties and may have impervious surfaces.

Please refer to Sheet No. 2A through Sheet No. 2C in the Appendix for the mapped locations of individual soil units.

3.2 U.S.G.S Quadrangle Maps

Based on our review of the Clearwater and Safety Harbor, Florida U.S.G.S. quadrangle maps, the existing ground surface elevation at West Bay Dr & Indian Rocks Rd and Seminole Blvd & 126th Ave intersections is approximately +35 to +40 feet, and +15 to +20 feet NAVD88 at East Bay Dr & US 19 intersection. The approximate site location is shown superimposed on a portion of the Riverview, Florida U.S.G.S.

quadrangle map presented on Sheet No. 1 in the Appendix.

4 FIELD EXPLORATION PROGRAM

Our field exploration program consisted of performing nine Standard Penetration Test (SPT) borings. The SPT borings were drilled to depths ranging between 30 and 35 feet below the existing ground surface. The SPT borings were advanced using methods consistent with ASTM D1586.

The SPT is a widely accepted test method of in-situ testing of foundation soils. A 2-foot long, 2-inch O.D.

split-barrel sampler attached to the end of a string of drilling rods is driven 18 inches into the ground by successive blows of a 140-pound hammer, freely dropping 30 inches. The number of blows needed for every 6 inches of penetration is recorded. The sum of the blows required for penetration of the second and third 6-inch increments of penetration constitutes the test result or N-value. After the test, the sampler is extracted from the ground and opened to describe the retained soil sample visually. The N-and East Bay Dr. & US 19 value has been empirically correlated with various soil properties allowing a conservative estimate of the behavior of soils under load. The tests are usually performed at 5-foot intervals. The test holes are advanced to the test elevations by rotary drilling with a cutting bit, using circulating fluid to remove the cuttings and hold the fine grains in suspension. The circulating fluid, a bentonitic drilling mud, is also used to keep the hole open below the water table by maintaining an excess hydrostatic pressure inside the hole. In some soil deposits, particularly highly pervious ones, the flush-coupled casing must be driven to just above the testing depth to keep the hole open and/or prevent the loss of circulating fluid. After completion of the test boring, the hole is then sealed by backfilling with cement grout.

The approximate locations of the borings are illustrated in the Report of Core Borings (Sheet No. 3 through 5 in the Appendix). The locations were determined in the field by estimating distances from existing site features. They should be considered accurate only to the degree implied by the method of measurement used.

5 LABORATORY TESTING PROGRAM

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

• Five organic content tests (ASTM D2974),

• 27 natural moisture content tests (ASTM D2216),

• 27 percent fines analyses (ASTM D1140), and

• 11 Atterberg limit determination tests (ASTM D4318)

The test results are presented in Table 1 in the Appendix and summarized on the Report of Core Borings (Sheet No. 3 through 5 in the Appendix) at the depths from which the samples were recovered. The soil descriptions shown on the boring profiles are based upon visual-manual procedures in accordance with local practice. Soil classification is generally according to the Unified Soil Classification System (ASTM D2487) and is also based on visual-manual procedures.

Additionally, one soil sample from each SPT borings, nine in total, were selected for environmental corrosion tests consisting of soil pH (FM 5-550), resistivity (FM 5-551), chlorides (FM 5-552), and sulfates (FM 5-553). The results are presented in Table 2 in the Appendix.

All soil samples retrieved during the field exploration program will be saved for 60 days from the date of this report and subsequently discarded unless requested otherwise in writing.

and East Bay Dr. & US 19

6 GENERAL SUBSURFACE CONDITIONS

The general subsurface conditions encountered during the field exploration program are shown on the soil boring profiles presented on the Report of Core Borings (Sheet No. 3 through 5 in the Appendix). Soil stratification is based on examining 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 gradual.

The groundwater depths shown on the boring profiles presented on the Report of Core Borings (Sheet No. 3 through 5 in the Appendix) represent the groundwater-surface encountered on the date shown.

Fluctuations in groundwater levels should be anticipated throughout the year due to seasonal variations in rainfall and tidal influence.

West Bay Drive at Indian Rocks Road (B1-B4) In general, the subsurface conditions encountered at this location consisted of very loose to medium dense SAND to SAND with silt (SP, SP-SM) from the ground surface to depths ranging from 17.5 to 22.5-

ft. bgs, followed by very loose to medium dense clayey SAND to silty SAND (SC, SM) to the termination depth of 30-ft. bgs. Very stiff lean CLAY (CL) was encountered in test boring B-3 from 22.5 to 30-ft. bgs.

Weight of the hammer (WOH) conditions were observed at test boring B-4 from 24 to 27.5-ft. bgs.

The depths at which groundwater was encountered in the boreholes ranged from 4 to 9 feet below the existing ground surface. At the time of our field exploration, groundwater was not apparent (GNA) at test boring B-2 before the introduction of drilling mud.

Seminole Boulevard at 126th Avenue (B1-B3) Conditions encountered at this location consisted of loose to medium dense SAND to SAND with silt (SP, SP-SM) from the ground surface to depths ranging from 22.5 to 27.5-ft. bgs, followed by very loose to medium dense clayey SAND (SC) to the termination depth of 30-ft. bgs. Very stiff lean CLAY (CL) was encountered in test boring B-3 from 22.5 to 30-ft. bgs. Loose SAND with clay (SP-SC) was encountered in test boring B-3 from 28 to 30-ft. bgs.

The depth at which groundwater was encountered in all boreholes was 4 feet below the existing ground surface during our field exploration.

East Bay Drive at US 19 (B1-B2) Soils encountered consisted of loose to dense SAND to SAND with silt (SP, SP-SM) from the ground surface to the termination depth of 30-ft. bgs in test boring B-1. In test boring B-2, very loose to loose SAND to SAND with silt (SP, SP-SM) was encountered from the ground surface to 22.5-ft. bgs, followed by very loose to medium dense silty SAND (SM) to 33-ft. bgs. Medium dense clayey SAND (SC) was encountered from 33 to 35-ft. bgs where the boring was terminated. Weight of the rod and weight of the hammer (WOR, WOH) conditions were observed at B-2 from 28.5 to 32-ft. bgs.

The depths at which groundwater was encountered in the boreholes were 7 and 5 feet below the existing ground surface at the time of our field exploration for test borings B-1 and B-2, respectively.

and East Bay Dr. & US 19

7 ANALYSIS AND RECOMMENDATIONS

It is assumed that the proposed signal mast arms will be designed on drilled shaft foundations installed in accordance with the requirements of Section 455 of the Florida Department of Transportation (FDOT) Standard Specifications for Road and Bridge Construction. Due to the presence of cohesionless soils and the drilled shaft extending well below the ambient groundwater level, we anticipate installing the drilled shaft using a slurry displacement (wet) drilling method. The slurry should be tested to ensure it meets FDOT requirements. We further expect that a temporary casing will be necessary to stabilize the near-surface soils. We recommend that the plan sheets include a note advising the foundation contractor that the subsurface materials encountered during our site exploration may become unstable and cave in during excavation of the drilled shaft. To keep with conservative design methods, it was assumed that the groundwater level could rise to be near the ground surface.

The soil properties for each significant stratum were averaged and are presented in Table 3 through Table 5 in the Appendix corresponding to the soil types encountered for each boring. The soil properties presented include cohesive strength, c, in pounds per square foot (psf); the angle of internal friction, φ, in degrees; the total unit weight, γt, in pounds per cubic foot (pcf) and the soil buoyant unit weight, γb, in pcf. These values are based on published empirical correlations from field SPT N-values.

According to the 2021 FDOT Standard Plans Index 649-030, drilled shaft foundations and base plates for standard mast arm assemblies are predesigned based on the soil criteria listed in the table below.

Required Conditions for Standard Drilled Shaft Design

Soil Classification: Cohesionless (fine sand)

Friction Angle: 30° or greater

Unit Weight: 50 pcf or greater*

N-value: 15

* The above values assume that the design groundwater level is at the ground surface.

The estimated strength parameters for all test borings are lower than the minimum criteria applicable to mast arm foundations predesigned per Standard Plans Index 649-030; consequently, a site-specific design will be required using the estimated parameters listed in the Appendix.

Very loose soil conditions were encountered at boring locations B-4 (West Bay Dr & Indian Rocks Rd) and B-2 (East Bay Dr and US19), where the split-spoon sampler advanced under the weight-of-the-drill-rods and tooling (WOR) and the weight-of-hammer (WOH). These conditions could potentially be associated with localized, very loose zones of saturated sands and/or raveling soils, and the contractor should anticipate such occurrences during construction. However, the scope of this investigation was not intended to evaluate potential subsidence activities, presence, or extent, and none was performed.

and East Bay Dr. & US 19

8 REPORT LIMITATIONS

The analysis and recommendations in this report are based on the data obtained from the nine soil borings performed at the approximate locations indicated on Sheet No. 3 through 5 in the Appendix.

This report does not reflect any variations that may occur adjacent to or between the borings. The nature and extent of variations may not become evident until during 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 represent 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 profiles and related information are based on the field logs and visual examination of selected samples in the laboratory. The delineation between soil types shown on the boring profiles is approximate, and the description represents our interpretation of subsurface conditions at the designated boring locations and on the particular date drilled.

This study is based on a relatively shallow exploration and is not intended to evaluate sinkhole potential.

This study does not include an evaluation of the environmental (ecological or hazardous/toxic material related) condition of the site and subsurface.

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.”

West Bay Dr & Indian Rocks Rd, Seminole Blvd & 126th Ave, and East Bay Dr & US 19

APPENDIX

Table 1 – Summary of Laboratory Results

Table 2 – Summary of Corrosion Series Testing Table 3 through Table 5 – Soil parameters

Sheet 1 – USGS Topographic Map Sheet 2A – USDA Soil Survey (West Bay Dr and Indian Rocks Rd)

Sheet 2B – USDA Soil Survey (126th Ave and Seminole Blvd) Sheet 2C – USDA Soil Survey (East Bay Dr and US Hwy 19 N)

Sheet 3 – Report of Core Borings (West Bay Dr and Indian Rocks Rd) Sheet 4 – Report of Core Borings (126th Ave and Seminole Blvd) Sheet 5 – Report of Core Borings (East Bay Dr and US Hwy 19 N)

Test Procedures Important Information About this Geotechnical-Engineering Report

Mast Arm Hardening West Bay Dr & Indian Rocks Rd, Seminole Blvd & 126th Ave and, East Bay Dr & US 19

Table 1: Summary of Laboratory Testing

Boring Depth (ft)

Percent Passing No.200

Liquid Limit

Plasticity Index

Organic Content

Natural Moisture Content

USCS

Classification

West Bay Dr & Indian Rocks Rd

B-1 18.5 - 20 12.7 -- -- -- 37.0 SM

B-1 23.5 - 25 12.4 87 58 -- 65.5 SC

B-1 28.5 - 30 14.9 -- -- -- 54.9 SC

B-2 4.0 - 6.0 4.4 -- -- -- 15.4 SP

B-2 13.5 - 15.0 5.7 -- -- -- 20.5 SP-SM

B-2 28.5 - 30.0 17.2 63 39 -- 39.5 SC

B-3 4.0 - 6.0 0.9 -- -- 1.6 60.4 SP

B-3 8.0 - 10.0 2.7 -- -- -- 25.7 SP

B-3 18.5 - 20.0 35.5 62 48 -- 39.4 SC

B-4 23.5 - 26.0 9.4 -- -- -- 35.9 SP-SM

B-4 26.0 - 28.0 15.7 40 26 -- 50.0 SC

B-4 30.0 - 31.5 16.2 50 30 -- 33.0 SC

Seminole Blvd & 126th Ave

B-1 8.0 - 10.0 8.1 -- -- -- 19.4 SP-SM

B-1 18.5 - 20.0 1.6 -- -- 0.9 20.9 SP

B-1 23.5 - 25 45.2 62 45 -- 24.2 SC

B-2 6.0 - 8.0 14.9 NP NP -- 18.3 SM

B-2 13.5 - 15 3.6 -- -- -- 24.6 SP

B-2 23.5 - 25 6.1 -- -- -- 29.4 SP-SM

B-3 8.0 - 10.0 11.2 -- -- -- 18.7 SP-SM

B-3 18.5 - 21.0 1.0 -- -- 2.1 23.8 SP

B-3 23.0 - 26.0 24.3 41 21 -- 37.7 SC

East Bay Dr & US 19

B-1 4.0 - 6.0 7.6 NP NP -- 20.1 SP-SM

B-1 18.5 - 20 8.0 -- -- 4.5 26.9 SP-SM

B-1 28.5 - 30 6.4 -- -- -- 19.9 SP-SM

B-2 15.0 - 17.0 6.9 -- -- 1.9 22.6 SP-SM

B-2 28.5 - 30.0 31.7 NP NP -- 28.9 SM

B-2 33.0 - 35.0 21.8 42 26 -- 29.7 SC

-- = Property Not Measured and East Bay Dr & US 19 Pinellas County, Florida MC2 Project No. T022112.019

Table 2: Summary of Corrosion Series Testing

Boring No.

(Depth - ft) pH Chlorides

(ppm) Sulfates (ppm)

Resistivity (ohm-cm)

Substructure Environmental Classification (Non-Marine)

Steel Concrete

West Bay Dr & Indian Rocks Rd

B-1 (8-15) 7.4 15 0 5,800 Slightly Aggressive Slightly Aggressive

B-2 (6-10) 7.0 15 93 4,300 Moderately Aggressive Slightly Aggressive

B-3 (6-8) 7.4 0 0 7,650 Slightly Aggressive Slightly Aggressive

B-4 (6-10) 7.3 15 0 10,000 Slightly Aggressive Slightly Aggressive

Seminole Blvd & 126th Ave

B-1 (4-8) 8.2 15 27 7,300 Slightly Aggressive Slightly Aggressive

B-2 (2-6) 8.7 0 12 6,800 Slightly Aggressive Slightly Aggressive

B-3 (4-8) 8.6 30 6 6,400 Slightly Aggressive Slightly Aggressive

East Bay Dr & US 19

B-1 (6-10) 7.9 15 0 3,200 Moderately Aggressive Slightly Aggressive

B-2 (2-6) 7.9 15 168 2,000 Moderately Aggressive Moderately Aggressive and East Bay Dr & US 19 Pinellas County, Florida MC2 Project No. T022112.019

Table 3. Soil Parameters - West Bay Drive at Indian Rocks Road

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)

B-1

0 – 4 Hand Auger SP-SM 100 38 28 0

4 – 6 4 SP-SM 100 38 28 0

6 – 12.5 6 SP, SP-SM 105 43 29 0

12.5 – 17.5 20 SP, SP-SM 112 50 31 0

17.5 – 22.5 5 SM 105 43 29 0

22.5 – 30 9 SC 107 45 29 0

B-2

0 – 4 Hand Auger SP, SP-SM 100 38 28 0

4 – 8 12 SP 110 48 30 0

8 – 12.5 29 SP 117 55 32 0

12.5 – 17.5 59 SP-SM 125 63 34 0

17.5 – 22.5 6 SP-SM 105 43 29 0

22.5 – 27.5 5 SC 105 43 29 0

27.5 – 30 25 SC 115 53 32 0

B-3

0 – 4 Hand Auger SP-SM 100 38 28 0

4 – 17.5 8 SP 105 43 29 0

17.5 – 22.5 5 SC 105 43 29 0

22.5 – 30 20 CL 125 63 0 2500

B-4

0 – 4 Hand Auger SP-SM 100 38 28 0

4 – 8 4 SP-SM 100 38 28 0

8 – 17.5 16 SP-SM 110 48 30 0

17.5 – 22.5 7 SP-SM 105 43 29 0

22.5 – 28 1 SP-SC 100 38 26 0

28 – 31.5 18 SC 110 48 30 0

and East Bay Dr & US 19 Pinellas County, Florida MC2 Project No. T022112.019

Table 4. Soil Parameters - 126th Avenue at Seminole Boulevard

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)

B-1

0 – 4 Hand Auger SP-SM 100 38 28 0

4 – 17.5 10 SP, SP-SM 107 45 29 0

17.5 – 22.5 19 SP 110 48 30 0

22.5 – 30 8 SC 105 43 29 0

B-2

0 – 4 Hand Auger SP, SP-SM 100 38 28 0

4 – 17.5 7 SP, SP-SM, SM 110 48 30 0

17.5 – 22.5 11 SP 110 48 30 0

22.5 – 30 8 SP-SM , SC 105 43 29 0

B-3

0 – 4 Hand Auger SP-SM 100 38 28 0

4 – 8 7 SP 105 43 29 0

8 – 17.5 24 SP, SP-SM 115 53 32 0

17.5 – 21 11 SP 110 48 30 0

21 – 28 2 SP-SM , SC 100 38 26 0

28 – 30 9 SP-SC 105 43 29 0

and East Bay Dr & US 19 Pinellas County, Florida MC2 Project No. T022112.019

Table 5. Soil Parameters - Roosevelt Boulevard at US 19

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)

B-1

0 – 4 Hand Auger SP-SM 100 38 28 0

4 – 6 4 SP-SM 100 38 28 0

6 – 17.5 10 SP, SP-SM 105 43 29 0

17.5 – 22.5 33 SP, SP-SM 120 58 33 0

22.5 – 30 15 SP, SP-SM 110 48 30 0

B-2

0 – 4 Hand Auger SP-SM 100 38 28 0

4 – 12.5 6 SP, SP-SM 105 43 29 0

12.5 – 22.5 2 SP-SM 100 38 26 0

22.5 – 27.5 8 SM 105 43 29 0

27.5 – 31.5 1 SM 100 38 26 0

31.5 – 35 12 SM, SC 110 48 30 0

USGS Topographic Map

West Bay Dr and Indian Rocks Rd

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.

CLEARWATER AND SAFETY HARBOR QUADRANGLES

FLORIDA-PINELLAS CO.

7.5 MINUTE SERIES TOPOGRAPHIC

NAVD: 1988 - DATE: 2018

JF

KF

KF

JF

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Jordan Fox, P.E.

FLORIDA LICENSE No. 87472

10/13/2021

10/13/2021

10/20/2021 T022112.019

Mast Arm Hardening - 3 Intersections

Pinellas County, FL

East Bay Dr and

US Hwy 19 N

126th Ave and

Seminole Blvd

USDA Soil Survey (West Bay Dr and Indian Rocks Rd)

NAMEDATE APPROVED BY:REVISION

2A

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 18 dated Aug 27, 2021, with aerial images taken Jan 20, 2020 - Jan 28, 2020.

JF

KF

KF

JF

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Jordan Fox, P.E.

FLORIDA LICENSE No. 87472

T022112.019

Mast Arm Hardening - 3 Intersections

Pinellas County, FL

10/13/2021

10/13/2021

10/20/2021

2B

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 18 dated Aug 27, 2021, with aerial images taken Jan 20, 2020 - Jan 28, 2020.

USDA Soil Survey (126th Ave and Seminole Blvd)

JF

KF

KF

JF

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Jordan Fox, P.E.

FLORIDA LICENSE No. 87472

T022112.019

Mast Arm Hardening - 3 Intersections

Pinellas County, FL

10/13/2021

USDA Soil Survey (East Bay Dr and US Hwy 19 N)

2C

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 18 dated Aug 27, 2021, with aerial images taken Jan 20, 2020 - Jan 28, 2020.

JF

KF

KF

JF

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Jordan Fox, P.E.

FLORIDA LICENSE No. 87472

T022112.019

Mast Arm Hardening - 3 Intersections

Pinellas County, FL

10/13/2021

V

20 40

Feet

B-1

B-2

B-4

B-3

(CL) Lean CLAY

LEGEND

GRANULAR MATERIALS- RELATIVE DENSITY

VERY LOOSE

LOOSE

MEDIUM

DENSE

VERY DENSE

£ 4

4-10

10-30

30-50

GREATER THAN 50

SILTS AND CLAYS CONSISTENCY

VERY SOFT

SOFT

FIRM

STIFF

VERY STIFF

HARD

£ 2

2-4

4-8

8-15

15-30

GREATER THAN 30

SAFETY HAMMER SPT N-VALUE (BLOWS/FT)

(SP-SM) Poorly-graded fine SAND with silt

(SC) Clayey fine SAND

(SM) Silty fine SAND

N SPT N-VALUE

NMC NATURAL MOISTURE CONTENT (%)

ESTIMATED SEASONAL HIGH

GROUNDWATER TABLE

-200 FINES PASSING A NO. 200 SIEVE (%)

GNA GROUNDWATER NOT APPARENT

HA HAND AUGER BORING

LL LIQUID LIMIT

PI PLASTICITY INDEX

OC ORGANIC CONTENT

PL PLASTIC LIMIT

(SP-SC) Poorly graded SAND with clay

SAFETY HAMMER SPT N-VALUE (BLOWS/FT)

AUTOMATIC HAMMER SPT N-VALUE (BLOWS/FT)

AUTOMATIC HAMMER SPT N-VALUE (BLOWS/FT)

£ 3

3-8

8-24

24-40

GREATER THAN 40

£ 1

1-3

3-6

6-12

12-24

GREATER THAN 24

WATER TABLE EXISTING

AT TIME OF BORING

(SP) Poorly-graded fine SAND

LOC LOSS OF CIRCULATION

WOH WEIGHT OF HAMMER

WOR WEIGHT OF ROD

D E

P T

H

F

E E

T

BORING NO.

DATE

B-1

10/5/21

Boring Terminated at 30 ft.

BORING NO.

DATE

B-2

10/6/21

BORING NO.

DATE

B-3

10/6/21

BORING NO.

DATE

B-4

10/5/21

Boring Terminated at 30 ft. Boring Terminated at 30 ft.

Boring Terminated at 31.5 ft.

HA

HA

N

GNA

NMC: 37%

-200: 12.7%

NMC: 54.9%

-200: 14.9%

Very loose, dark brown, poorly graded SAND with silt (SP-SM)

Loose to medium dense, dark brown, poorly graded SAND (SP)

Loose, brown, silty SAND (SM)

Loose to medium dense, gray to greenish gray, clayey SAND (SC)

Dark brown, poorly graded

SAND with silt (SP-SM) and rock fragments

Medium dense, yellowish brown, poorly graded SAND (SP)

Loose to very dense, yellow to reddish brown, poorly graded SAND with silt (SP-SM)

Loose to medium dense, greenish gray, clayey SAND (SC)

Dark gray to yellowish brown, poorly graded SAND with silt (SP-SM)

Loose to medium dense, greenish gray to pale brown, poorly graded SAND (SP)

Loose, gray, clayey SAND (SC)

Very stiff, gray, sandy CLAY (CL) with trace limestone fragments

Very loose to medium dense, gray to yellowish brown, poorly graded SAND with silt (SP-SM) and trace limerock fragments

Loose to medium dense, greenish gray, clayey SAND (SC)

(5'-6') WOH

D E

P T

H

F

E E

T

NMC: 65.5%

-200: 12.4%

LL: 87

PI: 58

N N N

Greenish gray, poorly graded

SAND with clay (SP-SC)

HA

HA

HA

HA

HA

HA

NMC: 15.4%

-200: 4.4%

NMC: 20.5%

-200: 5.7%

NMC: 39.5%

-200: 17.2%

LL: 63

PI: 39

NMC: 50%

-200: 15.7%

LL: 40

PI: 26

NMC: 35.9%

-200: 9.4%

NMC: 39.4%

-200: 35.5%

LL: 62

PI: 48

NMC: 25.7%

-200: 2.7%

WOH

(24'-27.5') WOH

WOH

NMC: 33%

-200: 16.2%

LL: 50

PI: 30

NMC: 60.4%

-200: 0.9%

OC: 1.6%

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.

PV

KF

KF

PV

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Prashanth Vaddu, P.E.

FLORIDA LICENSE No. 75144

T022112.019

Mast Arm Hardening - 3 Intersections

Pinellas County, FL

LEGEND:

Plan Provided By: Cardno

Approximate Boring Location

Report of Core Borings (West Bay Dr and Indian Rocks Beach)

10/13/2021

4/28/2022

V

32.8084 65.6168

131.2337

Feet

V

V

B-3

B-1

B-2

(CL) Lean CLAY

LEGEND

GRANULAR MATERIALS- RELATIVE DENSITY

VERY LOOSE

LOOSE

MEDIUM

DENSE

VERY DENSE

£ 4

4-10

10-30

30-50

GREATER THAN 50

SILTS AND CLAYS CONSISTENCY

VERY SOFT

SOFT

FIRM

STIFF

VERY STIFF

HARD

£ 2

2-4

4-8

8-15

15-30

GREATER THAN 30

SAFETY HAMMER SPT N-VALUE (BLOWS/FT)

(SP-SM) Poorly-graded fine SAND with silt

(SC) Clayey fine SAND

(SM) Silty fine SAND

N SPT N-VALUE

NMC NATURAL MOISTURE CONTENT (%)

ESTIMATED SEASONAL HIGH

GROUNDWATER TABLE

-200 FINES PASSING A NO. 200 SIEVE (%)

GNA GROUNDWATER NOT APPARENT

HA HAND AUGER BORING

LL LIQUID LIMIT

PI PLASTICITY INDEX

OC ORGANIC CONTENT

PL PLASTIC LIMIT

(SP-SC) Poorly graded SAND with clay

SAFETY HAMMER SPT N-VALUE (BLOWS/FT)

AUTOMATIC HAMMER SPT N-VALUE (BLOWS/FT)

AUTOMATIC HAMMER SPT N-VALUE (BLOWS/FT)

£ 3

3-8

8-24

24-40

GREATER THAN 40

£ 1

1-3

3-6

6-12

12-24

GREATER THAN 24

WATER TABLE EXISTING

AT TIME OF BORING

(SP) Poorly-graded fine SAND

LOC LOSS OF CIRCULATION

WOH WEIGHT OF HAMMER

WOR WEIGHT OF ROD

D E

P T

H

F

E E

T

D E

P T

H

F

E E

T

BORING NO.

DATE

B-1

10/5/21

Boring Terminated at 30 ft.

Gray to light brown, poorly graded SAND with silt (SP-SM)

Loose, gray to brownish gray, poorly graded SAND (SP)

Medium dense, light gray to dark brown, poorly graded SAND (SP)

Loose to medium dense, greenish gray, clayey SAND (SC)

N

HA

HA

BORING NO.

DATE

B-2

10/6/21

Boring Terminated at 30 ft.

Loose, light brown to light gray, poorly graded SAND with silt (SP-SM)

Loose, grayish brown, silty SAND (SM)

Loose, greenish gray, poorly graded

SAND with silt (SP-SM)

Loose, grayish brown, clayey SAND (SC)

N

HA

HA

BORING NO.

DATE

B-3

10/6/21

Boring Terminated at 30 ft.

Gray to yellowish brown, poorly graded SAND with silt (SP-SM)

Loose to medium dense, light gray, poorly graded SAND (SP)

Very loose, brownish gray, clayey SAND (SC)

N

HA

HA

Very loose, dark gray, poorly graded SAND with silt (SP-SM)

Loose, grayish brown, poorly graded SAND with silt (SP-SM)

Loose to medium dense, dark gray to grayish brown, poorly graded SAND (SP)

Loose to medium dense, brownish gray, poorly graded SAND with silt (SP-SM)

Loose, brownish gray, poorly graded SAND with clay (SP-SC)

NMC: 23.8%

-200: 1%

OC: 2.1%

NMC: 37.7%

-200: 24.3%

LL: 41

PI: 21

NMC: 29.4%

-200: 6.1%

NMC: 24.6%

-200: 3.6%

NMC: 18.3%

-200: 14.9%

LL: NP

PI: NP

NMC: 19.4%

-200: 8.1%

NMC: 24.2%

-200: 45.2%

LL: 62

PI: 45

NMC: 20.9%

-200: 1.6%

OC: 0.9%

NMC: 18.7%

-200: 11.2%

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.

KF

KF

T022112.019

Mast Arm Hardening - 3 Intersections

Pinellas County, FL

LEGEND:

Plan Provided By: Cardno

Approximate Boring Location

Report of Core Borings (126th Ave and Seminole Blvd)

10/13/2021

10/13/2021

4/28/2022

PV

PV

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Prashanth Vaddu, P.E.

FLORIDA LICENSE No. 75144

B

20 40

Feet

B-1

B-2

(CL) Lean CLAY

LEGEND

GRANULAR MATERIALS- RELATIVE DENSITY

VERY LOOSE

LOOSE

MEDIUM

DENSE

VERY DENSE

£ 4

4-10

10-30

30-50

GREATER THAN 50

SILTS AND CLAYS CONSISTENCY

VERY SOFT

SOFT

FIRM

STIFF

VERY STIFF

HARD

£ 2

2-4

4-8

8-15

15-30

GREATER THAN 30

SAFETY HAMMER SPT N-VALUE (BLOWS/FT)

(SP-SM) Poorly-graded fine SAND with silt

(SC) Clayey fine SAND

(SM) Silty fine SAND

N SPT N-VALUE

NMC NATURAL MOISTURE CONTENT (%)

ESTIMATED SEASONAL HIGH

GROUNDWATER TABLE

-200 FINES PASSING A NO. 200 SIEVE (%)

GNA GROUNDWATER NOT APPARENT

HA HAND AUGER BORING

LL LIQUID LIMIT

PI PLASTICITY INDEX

OC ORGANIC CONTENT

PL PLASTIC LIMIT

(SP-SC) Poorly graded SAND with clay

SAFETY HAMMER SPT N-VALUE (BLOWS/FT)

AUTOMATIC HAMMER SPT N-VALUE (BLOWS/FT)

AUTOMATIC HAMMER SPT N-VALUE (BLOWS/FT)

£ 3

3-8

8-24

24-40

GREATER THAN 40

£ 1

1-3

3-6

6-12

12-24

GREATER THAN 24

WATER TABLE EXISTING

AT TIME OF BORING

(SP) Poorly-graded fine SAND

LOC LOSS OF CIRCULATION

WOH WEIGHT OF HAMMER

WOR WEIGHT OF ROD

BORING NO.

DATE

B-1

10/6/21

Boring Terminated at 30 ft.

Loose, dark gray to pale brown, poorly graded SAND with silt (SP-SM) with trace limerock

Loose to medium dense, light gray, poorly graded SAND (SP)

Loose to dense, dark gray, poorly graded SAND with silt (SP-SM)

Medium dense, pale brown, poorly graded SAND (SP)

N

HA

HA

BORING NO.

DATE

B-2

10/6/21

Boring Terminated at 35 ft.

N

HA

HA

D E

P T

H

F

E E

T

D E

P T

H

F

E E

T

Loose, gray to grayish brown, poorly graded SAND with silt (SP-SM)

Loose, grayish brown to light gray, poorly graded SAND (SP)

Very loose, dark gray to dark brown, poorly graded SAND with silt (SP-SM)

(20'-21') WOH

(28.5'-32') WOH

Medium dense, gray, clayey SAND (SC)

Very loose to medium dense, dark brown, silty SAND (SM)

NMC: 20.1%

-200: 7.6%

LL: NP

PI: NP

NMC: 28.9%

-200: 31.7%

LL: NP

PI: NP

NMC: 29.7%

-200: 21.8%

LL: 42

PI: 26

NMC: 22.6%

-200: 6.9%

OC: 1.9%

NMC: 26.9%

-200: 8%

OC: 4.5%

NMC: 19.9%

-200: 6.4%

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.

Report of Core Borings (East Bay Dr and US Hwy 19 N)

KF

KF

T022112.019

Mast Arm Hardening - 3 Intersections

Pinellas County, FL

LEGEND:

Plan Provided By: Cardno

Approximate Boring Location

10/13/2021

10/13/2021

4/28/2022

PV

PV

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Prashanth Vaddu, P.E.

FLORIDA LICENSE No. 75144

TEST PROCEDURES

The general field procedures employed by MC Squared, Inc. (MC2) are summarized in the American Society for Testing and Materials (ASTM) Standard D420 which is entitled "Investigating and Sampling Soil and Rock". This recommended practice lists recognized methods for determining soil and rock distribution and groundwater conditions. These methods include geophysical and in-situ methods as well as borings.

Standard Drilling Techniques To obtain subsurface samples, borings are drilled using one of several alternate techniques depending upon the subsurface conditions. Some of these techniques are:

In Soils:

a) Continuous hollow stem augers.

b) Rotary borings using roller cone bits or drag bits, and water or drilling mud to flush the hole.

c) "Hand" augers.

In Rock:

a) Core drilling with diamond-faced, double or triple tube core barrels.

b) Core boring with roller cone bits.

The drilling method used during this exploration is presented in the following paragraph.

Hollow Stem Augering: A hollow stem augers consists of a hollow steel tube with a continuous exterior spiral flange termed a flight. The auger is turned into the ground, returning the cuttings along the flights. The hollow center permits a variety of sampling and testing tools to be used without removing the auger.

Core Drilling: Soil drilling methods are not normally capable of penetrating through hard cemented soil, weathered rock, coarse gravel or boulders, thin rock seams, or the upper surface of sound, continuous rock. Material which cannot be penetrated by auger or rotary soil-drilling methods at a reasonable rate is designated as “refusal material”. Core drilling procedures are required to penetrate and sample refusal materials.

Prior to coring, casing may be set in the drilled hole through the overburden soils, to keep the hole from caving and to prevent excessive water loss. The refusal materials are then cored according to ASTM D-2113 using a diamond-studded bit fastened to the end of a hollow, double or triple tube core barrel. This device is rotated at high speeds, and the cuttings are brought to the surface by circulating water. Core samples of the material penetrated are protected and retained in the swivel-mounted inner tube. Upon completion of each drill run, the core barrel is brought to the surface, the core recovery is measured, and the core is placed, in sequence, in boxes for storage and transported to our laboratory.

Sampling and Testing in Boreholes Several techniques are used to obtain samples and data in soils in the field; however the most common methods in this area are:

a) Standard Penetrating Testing

b) Undisturbed Sampling

c) Dynamic Cone Penetrometer Testing

d) Water Level Readings

The procedures utilized for this project are presented below.

Standard Penetration Testing: At regular intervals, the drilling tools are removed and soil samples obtained with a standard 2 inch diameter split tube sampler connected to an A or N-size rod. The sampler is first seated 6 inches to penetrate any loose cuttings, and then driven an additional 12 inches with blows of a 140 pound safety hammer falling 30 inches. Generally, the number of hammer blows required to drive the sampler the final 12 inches is designated the "penetration resistance" or "N" value, in blows per foot (bpf). The split barrel sampler is designed to retain the soil penetrated, so that it may be returned to the surface for observation.

Representative portions of the soil samples obtained from each split barrel sample are placed in jars, sealed and transported to our laboratory.

The standard penetration test, when properly evaluated, provides an indication of the soil strength and compressibility. The tests are conducted according to ASTM Standard D1586. The depths and N-values of standard penetration tests are shown on the Boring Logs. Split barrel samples are suitable for visual observation and classification tests but are not sufficiently intact for quantitative laboratory testing.

Water Level Readings: Water level readings are normally taken in the borings and are recorded on the Boring Records. In sandy soils, these readings indicate the approximate location of the hydrostatic water level at the time of our field exploration. In clayey soils, the rate of water seepage into the borings is low and it is generally not possible to establish the location of the hydrostatic water level through short-term water level readings. Also, fluctuation in the water level should be expected with variations in precipitation, surface run-off, evaporation, and other factors. For long-term monitoring of water levels, it is necessary to install piezometers.

The water levels reported on the Boring Logs are determined by field crews immediately after the drilling tools are removed, and several hours after the borings are completed, if possible.

The time lag is intended to permit stabilization of the groundwater level that may have been disrupted by the drilling operation.

Occasionally the borings will cave-in, preventing water level readings from being obtained or trapping drilling water above the cave-in zone.

BORING LOGS

The subsurface conditions encountered during drilling are reported on a field boring log prepared by the Driller. The log contains information concerning the boring method, samples attempted and recovered, indications of the presence of coarse gravel, cobbles, etc., and observations of groundwater. It also contains the driller's interpretation of the soil conditions between samples. Therefore, these boring records contain both factual and interpretive information. The field boring records are kept on file in our office.

After the drilling is completed a geotechnical professional classifies the soil samples and prepares the final Boring Logs, which are the basis for our evaluations and recommendations.

SOIL CLASSIFICATION

Soil classifications provide a general guide to the engineering properties of various soil types and enable the engineer to apply his past experience to current problems. In our investigations, samples obtained during drilling operations are examined in our laboratory and visually classified by an engineer. The soils are classified according to consistency (based on number of blows from standard penetration tests), color and texture. These classification descriptions are included on our Boring Logs.

The classification system discussed above is primarily qualitative and for detailed soil classification two laboratory tests are necessary; grain size tests and plasticity tests. Using these test results the soil can be classified according to the AASHTO or Unified Classification Systems (ASTM D-2487). Each of these classification systems and the in-place physical soil properties provides an index for estimating the soil's behavior. The soil classification and physical properties are presented in this report.

The following table presents criteria that is typically utilized in the classification and description of soil and rock samples for preparation of the Boring Logs.

Relative Density of Cohesionless Soils

From Standard Penetration Test

(Auto Hammer SPT N-Values)

Consistency of Cohesive Soils

(Auto Hammer SPT N-Values)

Very Loose < 3 bpf

Loose 3 - 8 bpf

Medium Dense 8 - 24 bpf

Dense 24 - 40 bpf

Very Dense > 40 bpf

(bpf = blows per foot, ASTM D 1586)

Very Soft < 1 bpf

Soft 1 - 3 bpf

Firm 3 - 6 bpf

Stiff 6 - 12 bpf

Very Stiff 12 - 24 bpf

Hard >24 bpf

Relative Hardness of Rock Particle Size Identification

Very Soft Hard Rock disintegrates or easily compresses to touch; can be hard to very hard soil.

Soft May be broken with fingers.

Moderately Soft May be scratched with a nail, corners and edges may be broken with fingers.

Moderately Hard Light blow of hammer required to break samples.

Hard Hard blow of hammer required to break sample.

Boulders Larger than 12"

Cobbles 3" - 12"

Gravel Coarse 3/4" - 3" Fine 4.76mm - 3/4"

Sand Coarse 2.0 - 4.76 mm Medium 0.42 - 2.00 mm Fine 0.42 - 0.074 mm

Fines (Silt or Clay) Smaller than 0.074 mm

Rock Continuity Relative Quality of Rocks

RECOVERY = Total Length of Core x 100 % Length of Core Run

RQD = Total core, counting only pieces > 4" long x 100 % Length of Core Run

Description Core Recovery

Incompetent Less than 40

Competent 40 - 70

Fairly Continuous 71 - 90

Continuous 91 - 100

Description RQD %

Very Poor 0 - 25 %

Poor 25 - 50 %

Fair 50 - 75 %

Good 75 - 90 %

Excellent 90 - 100 %

Geotechnical-Engineering Report Important Information about This

Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.

While you cannot eliminate all such risks, you can manage them. The following information is provided to help.

The Geoprofessional Business Association (GBA) has prepared this advisory to help you – assumedly a client representative – interpret and apply this geotechnical-engineering report as effectively as possible. In that way, clients can benefit from a lowered exposure to the subsurface problems that, for decades, have been a principal cause of construction delays, cost overruns, claims, and disputes. If you have questions or want more information about any of the issues discussed below, contact your GBA-member geotechnical engineer.

Active involvement in the Geoprofessional Business Association exposes geotechnical engineers to a wide array of risk-confrontation techniques that can be of genuine benefit for everyone involved with a construction project.

Geotechnical-Engineering Services Are Performed for Specific Purposes, Persons, and Projects Geotechnical engineers structure their services to meet the specific needs of their clients. A geotechnical-engineering study conducted for a given civil engineer will not likely meet the needs of a civil-works constructor or even a different civil engineer. Because each geotechnical-engineering study is unique, each geotechnical-engineering report is unique, prepared solely for the client. Those who rely on a geotechnical-engineering report prepared for a different client can be seriously misled. No one except authorized client representatives should rely on this geotechnical-engineering report without first conferring with the geotechnical engineer who prepared it. And no one

– not even you – should apply this report for any purpose or project except the one originally contemplated.

Read this Report in Full Costly problems have occurred because those relying on a geotechnical-engineering report did not read it in its entirety. Do not rely on an executive summary. Do not read selected elements only. Read this report in full.

You Need to Inform Your Geotechnical Engineer about Change Your geotechnical engineer considered unique, project-specific factors when designing the study behind this report and developing the confirmation-dependent recommendations the report conveys. A few typical factors include:

• the client’s goals, objectives, budget, schedule, and risk-management preferences;

• the general nature of the structure involved, its size, configuration, and performance criteria;

• the structure’s location and orientation on the site; and

• other planned or existing site improvements, such as retaining walls, access roads, parking lots, and underground utilities.

Typical changes that could erode the reliability of this report include those that affect:

• the site’s size or shape;

• the function of the proposed structure, as when it’s changed from a parking garage to an office building, or from a light-industrial plant to a refrigerated warehouse;

• the elevation, configuration, location, orientation, or weight of the proposed structure;

• the composition of the design team; or

• project ownership.

As a general rule, always inform your geotechnical engineer of project changes – even minor ones – and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered.

This Report May Not Be Reliable Do not rely on this report if your geotechnical engineer prepared it:

• for a different client;

• for a different project;

• for a different site (that may or may not include all or a portion of the original site); or

• before important events occurred at the site or adjacent to it; e.g., man-made events like construction or environmental remediation, or natural events like floods, droughts, earthquakes, or groundwater fluctuations.

Note, too, that it could be unwise to rely on a geotechnical-engineering report whose reliability may have been affected by the passage of time, because of factors like changed subsurface conditions; new or modified codes, standards, or regulations; or new techniques or tools. If your geotechnical engineer has not indicated an “apply-by” date on the report, ask what it should be, and, in general, if you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying it. A minor amount of additional testing or analysis – if any is required at all – could prevent major problems.

Most of the “Findings” Related in This Report Are Professional Opinions Before construction begins, geotechnical engineers explore a site’s subsurface through various sampling and testing procedures.

Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing were performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgment to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ – maybe significantly – from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team from project start to project finish, so the individual can provide informed guidance quickly, whenever needed.

This Report’s Recommendations Are Confirmation-Dependent The recommendations included in this report – including any options or alternatives – are confirmation-dependent. In other words, they are not final, because the geotechnical engineer who developed them relied heavily on judgment and opinion to do so. Your geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions revealed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you fail to retain that engineer to perform construction observation.

This Report Could Be Misinterpreted Other design professionals’ misinterpretation of geotechnical-engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a full-time member of the design team, to:

• confer with other design-team members,

• help develop specifications,

• review pertinent elements of other design professionals’ plans and specifications, and

• be on hand quickly whenever geotechnical-engineering guidance is needed.

You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction observation.

Give Constructors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation.