Geotechnical_Report.pdf

REPORT OF GEOTECHNICAL EXPLORATION

53rd AVENUE NORTH FORCE MAIN

PINELLAS COUNTY, FLORIDA

AREHNA PROJECT NO. B-22-007.03REV

December 19, 2022

Prepared For:

Halff Associates, Inc.

1000 N. Ashley Drive, Suite 900 Tampa, Florida 33602

Prepared By:

AREHNA Engineering, Inc.

5012 West Lemon Street Tampa, Florida 33609 www.arehna.com

5012 West Lemon Street Tampa, Florida 33609 Ph 813.944.3464 │ Fax 813.944.4959

December 19, 2022

Mr. H. Phillip Keyes, PE Halff Associates, Inc.

1000 N. Ashley Drive, Suite 900 Tampa, Florida 33602

Subject: Report of Geotechnical Exploration 53rd Avenue North Force Main Replacement Along 53rd Avenue North from Duhme Road to 106th St. North Pinellas County, Florida 33708 AREHNA Project B-22-007.03.REV

AREHNA Engineering, Inc. (AREHNA) is pleased to submit this report of our geotechnical exploration for the proposed project. Services were conducted in general accordance with AREHNA Proposal B.Prop-22-176 revised September 1, 2022. The purpose of our geotechnical study was to obtain information on the general subsurface conditions at the project site for a new force main installation in Pinellas County, Florida.

This report presents our understanding of the project, outlines our exploratory procedures, documents the field data obtained, and provides our recommendations for the proposed construction based on the borings completed.

AREHNA appreciates the opportunity to have assisted Halff Associates, Inc. on this project. Should you have any questions with regards to this report, or if we can be of any further assistance, please contact this office.

Best Regards, AREHNA ENGINEERING, INC.

FLORIDA BOARD OF PROFESSIONAL ENGINEERS CERTIFICATE OF AUTHORIZATION NO. 28410

This item has been digitally signed and sealed by:

Gordon Appleton, E.I. Andy Tao, P.E.

Engineer Intern Geotechnical Engineer Florida Registration 88520

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

Distribution: 1 – Addressee - Electronic 1 – File

53rd Avenue North Force Main December 19. 2022 Pinellas County, Florida AREHNA Project B-22-007.03.REV ii

TABLE OF CONTENTS

Page

1.0 PROJECT INFORMATION AND SCOPE OF WORK

1.1 Site Description and Project Characteristics

1.2 Scope of Work

2.0 FIELD EXPLORATION AND LABORATORY TESTING

2.1 Field Exploration

2.2 Laboratory Testing

3.0 SITE AND SUBSURFACE CONDITIONS

3.1 USGS Topographic Data

3.2 USDA Natural Resources Conservation Service Data

3.3 Subsurface Conditions

3.4 Groundwater Conditions

3.5 Estimated Seasonal High Groundwater Level

4.0 GENERAL SITE PREPARATION

4.1 General

4.2 On-Site Soil Suitability

4.3 Excavation and Backfill

4.4 Dewatering

4.5 Pipeline Bedding

4.6 Horizontal Directional Drilling

4.7 General Construction Monitoring and Testing Guidelines

5.0 BASIS FOR RECOMMENDATIONS

LIST OF APPENDICES

APPENDIX A

USDA & USGS Vicinity Maps – Sheet 1 Boring Location Plan – Sheet 2 Soil Boring Profiles – Sheets 3A and 3B

APPENDIX B

Summary of Laboratory Test Results – Table 1 Summary of Recommended Soil Parameters – Table 2 Field and Laboratory Test Procedures

1 | P a g e

1.0 PROJECT INFORMATION AND SCOPE OF WORK

1.1 Site Description and Project Characteristics

The project site is located along 53rd Avenue North from Duhme Road to 106th St N. in Pinellas County, Florida.

The proposed construction includes the installation of either a 20-inch or 24-inch force main. We understand that the force main will be installed utilizing horizontal directional drilling (HDD) to depths of approximately 10 to 15 feet below existing ground surface (bgs) and open cut to depths of 4 to 6 feet bgs. On the eastern portion of the alignment the open cut construction will reach depths up to 11 feet to tie in with the existing force main.

1.2 Scope of Work

The purpose of our geotechnical study was to obtain information on the general subsurface conditions at the proposed project site. The subsurface materials encountered were evaluated with respect to the available project characteristics. In this regard, engineering assessments for the following items were formulated:

Subsurface soil conditions and general location and description of potentially deleterious materials encountered in the borings which may have an impact on the proposed construction.

Identification of the existing groundwater levels and estimated normal seasonal high groundwater fluctuations.

Evaluation of the subsurface soil properties and general recommendations for the proposed constructions.

General site preparation recommendations including the suitability of excavated soils.

The following services were performed to achieve the above-outlined objectives:

Requested 48-hour utility location services from Sunshine811.

Performed a total of 4 Standard Penetration Test (SPT) borings to depths of 15 to 25 feet at the project site. Samples were collected, and Standard Penetration Test resistances measured continuously for the top ten feet and at approximate intervals of five feet, thereafter.

Visually classified and stratified soil samples in the laboratory using the Unified Soil Classification System.

Reported the results of the field exploration and engineering analysis. The results of the subsurface exploration are presented in a written report signed and sealed by a professional engineer specializing in geotechnical engineering.

2 | P a g e

2.0 FIELD EXPLORATION AND LABORATORY TESTING

2.1 Field Exploration

AREHNA completed four (4) SPT borings extending to depths of 15 to 25 feet below the existing ground surface along 53rd Avenue North.

The borings were performed with the use of a drill rig using Bentonite “Mud” drilling procedures. Samples were collected and Standard Penetration Test resistances were measured at approximate intervals of two feet for the top ten feet, and at intervals of five feet, thereafter. The upper four feet of the SPT borings were manually augured to avoid any potential conflict with unmarked underground utilities. The soil sampling was performed in general accordance with ASTM Test Designation D-1586, entitled “Penetration Test and Split-Barrel Sampling of Soils.” Representative portions of these soil samples were sealed in glass jars, labeled and transferred to AREHNA’s Tampa office for appropriate classification by a Geotechnical Engineer.

Samples will be retained for 90 days after the date of the report and then disposed, unless other arrangements have been made.

The approximate locations of the SPT borings are shown on Sheet 2 in Appendix A. The borings were located in the field using Global Positioning System (GPS) coordinates.

2.2 Laboratory Testing

Laboratory testing, consisting of natural moisture content, single sieve (#200) gradation testing, Atterberg Limits, and organic content, was performed on representative soil samples. The results of the laboratory testing are presented on the Soil Boring Profiles on Sheets 3A and 3B in Appendix A and are summarized on Table 1 in Appendix B.

3 | P a g e

3.0 SITE AND SUBSURFACE CONDITIONS

3.1 USGS Topographic Data

The topographic survey map published by the United States Geological Survey was reviewed for ground surface features at the proposed project location, as shown on Sheet 1 in Appendix A. Based on this review, natural ground surface elevations at the project site are approximately EL. +25 to +30 feet National Geodetic Vertical Datum of 1929 (NGVD 29). The lowest elevations are at the eastern end of the alignment. Elevations referenced in this report were provided by Halff and Associates.

3.2 USDA Natural Resources Conservation Service Data

The United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) soil survey for Pinellas County indicates that the natural soils at the project site consist of the following soil units:

Soil Unit Number Soil Name

Depth to High Water Table

(inches)

4 Astatula soils and Urban land, 0 to 5 percent slopes >80

16 Matlacha and St. Augustine soils and Urban land 18 - 36

17 Myakka soils and urban land 6 - 18

28 Seffner soils and urban land 18 - 42

The data provided above may not account for fill or other construction activities related to development of the roadway. The USDA Soil Survey map for the project site is attached as Sheet 1 in Appendix A.

3.3 Subsurface Conditions

A pictorial representation of the subsurface conditions encountered by the borings is shown on the Soil Boring Profiles, Sheets 3A and 3B in Appendix A. These profiles and the following soil conditions highlight the general subsurface stratification.

The SPT borings generally encountered very loose to dense fine sands (SP, SP-SM) with shell fragments from just below the pavement to depths of approximately 12 to 22 feet (EL. +27.9 to +2.0 feet, NAVD88) below ground surface (bgs). SPT-01 encountered a layer of loose gray clayey sand (SC) at depths of approximately 12 feet bgs to the termination depth of 15 feet bgs (EL. +15.9 to +12.9 feet, NAVD88). SPT-02 and SPT-04 encountered a layer of loose silty sand at depths of approximately 22 feet bgs to the boring termination

4 | P a g e depths of 25 feet bgs (EL. +4.6 to -1.0 feet, NAVD88). SPT-04 also encountered a layer of decayed wood and gravel with some silty sand at depths of approximately 2 to 6 feet bgs (EL. +22.0 to +18.0 feet, NAVD88).

The Soil Boring Profile Sheets 3A and 3B in Appendix A should be consulted for a detailed description of the subsurface conditions encountered at each boring location. When reviewing the boring records and the subsurface profiles, it should be understood that soil conditions may vary between and away from boring locations.

3.4 Groundwater Conditions

The groundwater level was generally encountered from 2.3 to 6.3 feet below existing grades (EL. +22.5 to +21.3 feet, NAVD88). Fluctuation in groundwater levels should be expected due to seasonal climatic changes, construction activity, rainfall variations, surface water runoff, and other site-specific factors. Since groundwater level variations are anticipated, design drawings and specifications should accommodate such possibilities and construction planning should be based on the assumption that variations will occur.

3.5 Estimated Seasonal High Groundwater Level

The Seasonal High Water Table (SHWT) is the highest average depth of soil saturation during the wet season in a normal year. SHWT estimations are based on the procedures for estimating SHWT elevations including an examination of county soil surveys and field verification by observation and identification of indicators within the soil profile.

Based on the information reported by the USDA, soils information obtained from the site, and our experience in the area, we estimate that the seasonal high water level will be encountered at EL. +22±0.5.

The water table should be relatively level. Thus, water table depths may slightly vary across the site due to variations in the ground surface elevation.

5 | P a g e

4.0 GENERAL SITE PREPARATION

4.1 General

We understand the force main replacement may be installed utilizing both open cut and Horizontal Directional Drilling (HDD) construction. The open cut is expected to be at depths of approximately 4 to 6 feet below ground surface (bgs), with the connection to existing facilities at the eastern end of the project site expected to be at depths of approximately 9 to 11 feet bgs. The HDD is expected to be primarily at depths of approximately 10 to 15 feet bgs. The HDD installation operation is the responsibility of the specialty contractor (i.e. the selection of HDD equipment and operation procedures are the choices of the specialty contractor). We have provided general guidelines for HDD operation below. Our general installation recommendations have been based on the site conditions encountered during our geotechnical investigation. AREHNA should be notified if the site conditions are different than stated in this report, so we may modify or amend our recommendations.

4.2 On-Site Soil Suitability

The borings indicate that sandy soils classified as SP and SP-SM are present at the site from the ground surface to depths of 12 to 22 feet and are suitable for use as backfill material, however the depths of the sandy soils are variable along the alignment of this project. Soil classified as clayey sand (SC) and silty sand (SM) are not suitable for reuse. SPT-02 encountered asphalt fragments to depths of 2 feet bgs (EL. +24.6 feet, NAVD88) and SPT-04 encountered wood debris at depths of 2 to 6 feet (EL. +22 to 18 feet, NAVD88).

These materials are considered deleterious material. If deleterious materials are encountered the area should be over-excavated at least 12 inches and backfilled with compacted, suitable structural fill. Soil excavated from below the groundwater level will be above the optimum moisture content required for compaction and will need to be dried before placement. Suitable structural fill materials should consist of fine to medium sand with less than 12 percent passing the No. 200 sieve and be free of rubble, organics, clay, debris and other unsuitable material. Any off-site materials used as fill should be approved by AREHNA prior to acquisition.

4.3 Excavation and Backfill

Excavations should be constructed in accordance with the current OSHA guidelines. The contractor is solely responsible for designing and constructing stable 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 contractor’s responsible person, 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.

6 | P a g e

The soils encountered are consistent with OSHA Class C soils and will not stand vertically in an open excavation below the groundwater level or for more than very short periods above the groundwater level. Soil should not be stockpiled adjacent to excavations unless the stockpile has been included in the analyses of the excavation stability. Excavations below the groundwater level will likely require a combination of sanded wellpoints and pumping from filtered sumps.

Any and all excavations should be backfilled with compacted fill. Fill should generally consist of dry fine sand with less than 12 percent passing the No. 200 sieve and be free of rubble, organics, clay, debris and other unsuitable material. Excavated soils should be suitable for re-use as fill. Imported fill, if needed, should be tested and approved prior to acquisition. Fill should be placed in loose lifts not exceeding 12 inches in thickness and should be compacted to a minimum of 95 percent of the Modified Proctor maximum dry density (ASTM D-1557). If compaction cannot be obtained with 12-inch lifts, thinner lifts may be required.

Prior to beginning compaction, soil moisture contents should be adjusted in order to facilitate proper compaction. A moisture content within 2 percentage points of the optimum indicated by the Modified Proctor Test (ASTM D-1557) is recommended prior to compaction of the fill.

4.4 Dewatering

The groundwater was encountered at all of the boring locations, generally between about 2.3 and 6.3-feet bgs (EL. +22.5 to +21.3 feet, NAVD88). Therefore, depending on the time of year construction is performed, dewatering may be required for excavations deeper than EL. +23 feet, NAVD88. Surface water runoff into excavation may also require dewatering. Dewatering can be accomplished using a sanded wellpoint system supplemented by a gravel bottom layer and pumping from a sump. Actual dewatering means and methods should be the responsibility of the contractor.

Groundwater fluctuations will likely occur due to seasonal variations, runoff, and other factors and should be considered when planning earthwork activities. The impact of runoff from adjacent properties, nearby water bodies, and other site-specific conditions which may affect groundwater recharge are beyond the scope of this exploration and should be considered when planning and designing a dewatering system.

4.5 Pipeline Bedding

For open cut construction, we recommend the pipeline be supported on a bedding layer consisting of at least 6 inches of granular soils (existing soil or fill) meeting the previous requirements for structural fill. Any utilities 3 feet or greater in diameter should be supported on at least 12 inches of structural fill/granular soils. The bedding layer should be compacted to at least 95 percent of the Modified Proctor maximum dry density (ASTM D-1557).

7 | P a g e

4.6 Horizontal Directional Drilling

Based on the SPT borings performed, the subsurface materials generally consist of very loose to medium dense fine sands (SP, SP-SM, SM, SC). The encountered sandy soils have a potential for caving. Limestone was not encountered.

Soil parameters for use in the HDD design software are presented on Table 2 in Appendix B.

Drilling Fluid - Drilling fluid should be used during drilling and back-reaming operations. Due to the sandy soils encountered during our investigation it is recommended that the drilling fluid be composed of clean water and bentonite. Other appropriate additives should be added at the discretion of the specialty contractor. The drilling fluid should be mixed thoroughly and be absent of any clumps or clods. Further, the drilling fluid should not be recycled and should be hauled off the site.

Heaving Potential - The soils encountered in our investigation have a low heaving potential. However, heaving may occur when attempting to back-ream too large of a hole. To minimize heaving, reaming process should be completed leaving the bored hole at full design diameter during pullback. The pullback barrel reamer should be no larger than the design bored diameter. The pullback rate should minimize overcutting of the borehole so that excessive voids are reduced and post installation settlement may be minimized.

Monitoring – The drilling and installation operations should be monitored continuously by experienced personnel trained in all aspects of directional drilling process. These procedures include accurate monitoring and control system to track the progress and exact location of the drilling head at all times. The drilling operator should maintain record on drilling fluid pumping rates, pressures, viscosity and density, etc.

throughout the entire course of drilling activities.

Horizontal and vertical adjustments should be made throughout the procedure so that the drilling profile matches the planned profile. The specific weight of the drilling fluid should be adjusted throughout the process to maintain hydrological stability. Jetting pressures should be limited to avoid drilling fluid release during drilling. However, should release of drilling fluid in the project area occur, operations should stop immediately and measures should be taken to contain release. Generic measures may include the following:

If release is detected, the drilling crew should take immediate corrective action to contain the release and to prevent migration offsite.

Pits and/or berms should be constructed around the borehole entry point to contain drilling fluid and return.

Containment equipment, including earth moving equipment, portable pumps, hand tools, sandbags, hay bales, silt fencing, lumber, and vacuum trucks, should be stored and readily available at the drilling site.

8 | P a g e

Any drilling seepage should be removed using a vacuum truck and then transported to an approved disposal site.

4.7 General Construction Monitoring and Testing Guidelines

Prior to initiating compaction operations, we recommend that representative samples of the structural fill material to be used and acceptable exposed in-place soils be collected and tested to determine their compaction and classification characteristics. The maximum dry density, optimum moisture content, gradation and plasticity characteristics should be determined. These tests are needed for compaction quality control of the structural fill and existing soils and to determine if the fill material is acceptable.

A representative number of in-place field density tests should be performed in the compacted existing soils and in each lift of structural fill or backfill to confirm that the required degree of compaction has been obtained. We recommend that at least one density test be performed for every lift of backfill and the bedding material for every 100 lineal feet of trench, testing at different locations within the 100-foot section at each lift.

9 | P a g e

5.0 BASIS FOR RECOMMENDATIONS

The analysis and recommendations submitted in this report are based upon the data obtained from the soil borings performed at the location indicated. Regardless of the thoroughness of a geotechnical exploration, there is always a possibility that conditions across site will be different from those encountered where the boring was drilled, and that conditions will not be as anticipated by the designers or contractors. In addition, the construction process itself may alter soil conditions. AREHNA is not responsible for the conclusions, opinions or recommendations made by others based on the data presented in this report.

APPENDIX A

USDA & USGS Vicinity Maps – Sheet 1

Boring Location Plan – Sheet 2

Soil Boring Profiles – Sheets 3A to 3B

REFERENCE: USDA SOIL SURVEY OF PINELLAS COUNTY, FLORIDA

TOWNSHIP:

RANGE:

SECTION:

USGS TOPOGRAPHIC MAP

REFERENCE: "SEMINOLE, FLORIDA" USGS QUADRANGLE MAP

USDA SOIL SURVEY MAP

TOWNSHIP:

RANGE:

SECTION:

N

0 1000

Feet

N

0 1000

Feet

DATE

APPROVED

REVISIONS

DATENAME

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

PREPARED BY:

NO. DESCRIPTIONS

Andy Tao, P.E.

SHEET NO.PROJECT NO.PROJECT NAME

D A r e h n a P r o j e c t s B r d

A v e

N

F o r c e

M a i n

B d w g

V

I C

D e c p m

USDA & USGS VICINITY MAPS

31 S

15 E

3, 4

53RD AVE N FORCE MAIN

PINELLAS COUNTY, FLORIDA

AT

DG

GA

B-22-007.03 Engineering,Inc.AREHNA

12296 Wiles Road, Coral Springs, FL 33076 Phone 954.417.8412 Fax 813.944.4959

Certificate of Authorization No. 28410

11/2022

11/2022

11/2022

SITE LOCATION SITE LOCATION

31 S

15 E

3, 4

AutoCAD SHX Text | Fax 813.944.4959 Fax 813.944.4959

53RD AVE N

SPT-01

D U

H M

E

R

D

SPT-02

SPT-03

53RD AVE N

T

H

S

T

N

L A

Z Y

L

K

E

L

N

N

L A

Z Y

L

T

H

W

A Y

B E

N

H

U R

C

T

SPT-04

53RD AVE N

R

D

V

E

T

H

S

T

N

S E

M I N

O L

E

B

L V

D

DATE

APPROVED

REVISIONS

DATENAME

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

PREPARED BY:

NO. DESCRIPTIONS

SHEET NO.PROJECT NO.PROJECT NAME

D A r e h n a P r o j e c t s B r c e

M a i n

B d

B

L P

D e c p m

BORING LOCATION PLAN

0 100

Feet

N

LEGEND

APPROXIMATE LOCATION OF SPT BORING

Andy Tao, P.E.

53RD AVE N FORCE MAIN

PINELLAS COUNTY, FLORIDA

AT

DG

GA

B-22-007.03 Engineering,Inc.AREHNA

12296 Wiles Road, Coral Springs, FL 33076 Phone 954.417.8412 Fax 813.944.4959

Certificate of Authorization No. 28410

11/2022

11/2022

11/2022

Soil Profile Notes:

1. The profiles depicted are of a generalized nature to highlight the major subsurface stratification features and material characteristics. The soil profiles include soil description, stratifications and penetration resistances. The stratifications shown on the boring profiles represent the conditions only at the actual boring location. Variations may occur and should be expected between boring locations. The stratifications represent the approximate boundary between subsurface materials and the actual transition may be gradual.

2. Groundwater levels generally fluctuate during periods of prolonged drought and extended rainfall and may be affected by man-made influences. In addition, a seasonal effect will also occur in which higher groundwater levels or temporary perched conditions are normally recorded in rainy seasons.

3. The Boring Locations Presented are Approximate and Based on Hand Held GPS with an Accuracy of +/- 10 Feet.

4. SPT borings were performed using a safety hammer.

DATE

APPROVED

REVISIONS

DATENAME

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

PREPARED BY:

NO. DESCRIPTIONS

3A

SHEET NO.PROJECT NO.PROJECT NAME

D A r e h n a P r o j e c t s B r c e

M a i n

B d

A

P

R F

D e c p m

SOIL BORING PROFILES

LESS THAN 3

3 to 8

8 to 24

24 to 40

GREATER THAN 40

VERY SOFT

SOFT

FIRM

STIFF

VERY STIFF

HARD

LESS THAN 1

1 to 3

3 to 6

6 to 12

12 to 24

GREATER THAN 24

AUTOMATIC

HAMMER

SAFETY

HAMMER

LESS THAN 4

4 to 10

10 to 30

30 to 50

GREATER THAN 50

LESS THAN 2

2 to 4

4 to 8

8 to 15

15 to 30

GREATER THAN 30

VERY LOOSE

LOOSE

MEDIUM

DENSE

VERY DENSE

SPT

(BLOWS/FT)

SPT

(BLOWS/FT)

SPT

(BLOWS/FT)

SPT

(BLOWS/FT)

SILTS AND CLAYS

CONSISTENCY

GRANULAR MATERIALS-

RELATIVE DENSITY

Andy Tao, P.E.

53RD AVE N FORCE MAIN

PINELLAS COUNTY, FLORIDA

AT

DG

GA

B-22-007.03 Engineering,Inc.AREHNA

12296 Wiles Road, Coral Springs, FL 33076 Phone 954.417.8412 Fax 813.944.4959

Certificate of Authorization No. 28410

11/2022

11/2022

11/2022

E L

E V

A T

I O

N

I

E

T

N

A V

D

N

HA

HA

E L

E V

A T

I O

N

E

T

N

A V

D

BORING TERMINATED

AT ELEVATION 12.9 FEET

LATITUDE: N 27.8202406

LONGITUDE: W 82.792879

SPT-01

N

HA

HA

BORING TERMINATED

AT ELEVATION 1.6 FEET

LATITUDE: N 27.8202178

LONGITUDE: W 82.7900406

11/21/22

SPT-02

11/21/22

PAVEMENT, BASE

AND/OR SUBGRADE

2.5" PAVEMENT

SAND AND SHELL STABILIZED SUBGRADE

GRAY CLAYEY SAND (SC)

LIGHT ORANGE-BROWN TO WHITE TO LIGHT BROWN

LIGHT BROWN SAND WITH TRACE SHELL FRAGMENTS (SP)

LIGHT BROWN FINE SAND WITH FEW SHELL FRAGMENTS (SP)

LIGHT BROWN SAND WITH TRACE SHELL AND ASPHALT

LIGHT BROWN-GRAY TO GRAY SAND WITH TRACE SHELL

BROWN SAND (SP)

LIGHT BROWN FINE SLIGHTLY SILTY SAND (SP-SM)

LIGHT BROWN SILTY SAND (SM)

FRAGMENTS (SP)

LEGEND

FINE SAND (SP/SP-SM)

SILTY SAND (SM)

GROUNDWATER TABLE AT THE TIME OF DRILLING

UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D

2488) GROUP SYMBOL AS DETERMINED BY VISUAL

REVIEW AND/OR LABORATORY TESTING

SP

SPT N-VALUE IN BLOWS/FOOT FOR 12 INCHES OF

PENETRATION

N

HAND AUGERHA

ELEV. 27.9'

ELEV. 26.6'

-200 FINES PASSING THE #200 STANDARD SIEVE (%)

LL LIQUID LIMIT (%)

PI PLASTICITY INDEX (%)

NMC NATURAL MOISTURE CONTENT (%)

OC ORGANIC CONTENT (%)

-200=46

NMC=38

LL=49

PI=23

-200=2

NMC=23

SAND (SP)

CLAYEY SAND (SC)

FRAGMENTS (SP)

HA

HA

BORING TERMINATED

AT ELEVATION 9.3 FEET

LATITUDE: N 27.8202014

LONGITUDE: W 82.7877045

N

BORING TERMINATED

AT ELEVATION -1.0 FEET

LATITUDE: N 27.8202631

LONGITUDE: W 82.7864684

11/21/22

11/21/22

2" PAVEMENT

9" LIMEROCK BASE MATERIAL

4" PAVEMENT

6.5" SHELL BASE MATERIAL

DARK BROWN FINE SAND (SP)

LIGHT BROWN SLIGHTLY SILTY SAND (SP-SM)

LIGHT BROWN SAND (SP)

LIGHT BROWN SLIGHTLY SILTY SAND WITH TRACE ROOTS (SP-SM)

DARK BROWN-GRAY SLIGHTLY SILTY SAND WITH TRACE SHELL

DARK BROWN-GRAY SLIGHTLY SILTY SAND WITH FEW SHELL

WOOD AND GRAVEL WITH SOME SILTY SAND

BROWN-GRAY SLIGHTLY SILTY SAND (SP-SM)

BROWN-GRAY SAND WITH TRACE DECAYED WOOD

DARK BROWN SLIGHTLY SILTY SAND WITH TRACE CEMENTED

DARK BROWN SLIGHTLY SILTY SAND (SP-SM)

DARK GRAY SILTY SAND WITH CEMENTED FRAGMENTS (SM)

AND CEMENTED SAND FRAGMENTS AND TRACE DECAYED

FRAGMENTS (SP)

SAND FRAGMENTS (SP-SM)

FRAGMENTS (SP-SM)

Soil Profile Notes:

1. The profiles depicted are of a generalized nature to highlight the major subsurface stratification features and material characteristics. The soil profiles include soil description, stratifications and penetration resistances. The stratifications shown on the boring profiles represent the conditions only at the actual boring location. Variations may occur and should be expected between boring locations. The stratifications represent the approximate boundary between subsurface materials and the actual transition may be gradual.

2. Groundwater levels generally fluctuate during periods of prolonged drought and extended rainfall and may be affected by man-made influences. In addition, a seasonal effect will also occur in which higher groundwater levels or temporary perched conditions are normally recorded in rainy seasons.

3. The Boring Locations Presented are Approximate and Based on Hand Held GPS with an Accuracy of +/- 10 Feet.

4. SPT borings were performed using a safety hammer.

DATE

APPROVED

REVISIONS

DATENAME

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

PREPARED BY:

NO. DESCRIPTIONS

3B

SHEET NO.PROJECT NO.PROJECT NAME

D A r e h n a P r o j e c t s B r c e

M a i n

B d

B

P

R F

D e c p m

SOIL BORING PROFILES

Andy Tao, P.E.

53RD AVE N FORCE MAIN

PINELLAS COUNTY, FLORIDA

AT

DG

GA

B-22-007.03 Engineering,Inc.AREHNA

12296 Wiles Road, Coral Springs, FL 33076 Phone 954.417.8412 Fax 813.944.4959

Certificate of Authorization No. 28410

11/2022

11/2022

11/2022

SPT-03

SPT-04

ELEV. 24.3'

ELEV. 24.0'

-200=3

NMC=23

OC=1

-200=2

NMC=21

LESS THAN 3

3 to 8

8 to 24

24 to 40

GREATER THAN 40

VERY SOFT

SOFT

FIRM

STIFF

VERY STIFF

HARD

LESS THAN 1

1 to 3

3 to 6

6 to 12

12 to 24

GREATER THAN 24

AUTOMATIC

HAMMER

SAFETY

HAMMER

LESS THAN 4

4 to 10

10 to 30

30 to 50

GREATER THAN 50

LESS THAN 2

2 to 4

4 to 8

8 to 15

15 to 30

GREATER THAN 30

VERY LOOSE

LOOSE

MEDIUM

DENSE

VERY DENSE

SPT

(BLOWS/FT)

SPT

(BLOWS/FT)

SPT

(BLOWS/FT)

SPT

(BLOWS/FT)

SILTS AND CLAYS

CONSISTENCY

GRANULAR MATERIALS-

RELATIVE DENSITY

PAVEMENT, BASE

AND/OR SUBGRADE

LEGEND

FINE SAND (SP/SP-SM)

SILTY SAND (SM)

GROUNDWATER TABLE AT THE TIME OF DRILLING

UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D

2488) GROUP SYMBOL AS DETERMINED BY VISUAL

REVIEW AND/OR LABORATORY TESTING

SP

SPT N-VALUE IN BLOWS/FOOT FOR 12 INCHES OF

PENETRATION

N

HAND AUGERHA

-200 FINES PASSING THE #200 STANDARD SIEVE (%)

LL LIQUID LIMIT (%)

PI PLASTICITY INDEX (%)

NMC NATURAL MOISTURE CONTENT (%)

OC ORGANIC CONTENT (%)

CLAYEY SAND (SC)

-5

E L

E V

A T

I O

N

E

T

N

A V

D

-5

E L

E V

A T

I O

N

E

T

N

A V

D

WOOD FRAGMENTS (SP-SM)

APPENDIX B

Summary of Laboratory Test Results – Table 1

Summary of Recommended Soil Parameters – Table 2

Field and Laboratory Test Procedures

#200 LL PI

Plasticity

Index

SPT ‐ 01 13.5' ‐ 15.0' SC 46 49 26 23 ‐ 38

SPT ‐ 02 8.0' ‐ 10.0' SP 2 ‐ ‐ ‐ ‐ 23

SPT ‐ 03 13.5' ‐ 15.0' SP 2 ‐ ‐ ‐ ‐ 21

SPT ‐ 04 8.0' ‐ 10.0' SP 3 ‐ ‐ ‐ 1 23

TABLE 1

SUMMARY OF LABORATORY TEST RESULTS

53rd Avenue N. Force Main

AREHNA Project No. B‐22‐007.03

PINELLAS COUNTY, FLORIDA

Boring No.

Sample

Depth

(feet)

Natural

Moisture

Content

Sieve Analysis

(% Passing)USCS

Classification

Atterberg Limits

(%) Organic

Content ɣ SAT ɣ SUB

4 23.9 8 SP 112 49.6 0 30 0.33 3.00

6 21.9 4 SP 102 39.6 0 29 0.35 2.88

12 15.9 11 SP 112 49.6 0 31 0.32 3.12

15 12.9 4 SC 102 39.6 0 27 0.38 2.66

4 22.6 8 SP 112 49.6 0 30 0.33 3.00

12 14.6 2 SP 102 39.6 0 29 0.35 2.88

22 4.6 14 SP 112 49.6 0 32 0.31 3.25

25 1.6 4 SM 102 39.6 0 27 0.38 2.66

12 12.3 9 SP 112 49.6 0 31 0.32 3.12

15 9.3 29 SP 120 57.6 0 37 0.25 4.02

4 20.0 6 SP 105 42.6 0 30 0.33 3.00

6 18.0 7 PT 90 27.6 0 5 0.84 1.19

12 12.0 3 SP 102 39.6 0 29 0.35 2.88

22 2.0 33 SP 125 62.6 0 38 0.24 4.20

25 ‐1.0 7 SM 112 49.6 0 28 0.36 2.77

TABLE 2

SUMMARY OF RECOMMENDED SOIL PARAMETERS

53RD AVENUE N. FORCE MAIN

APPROXIMATE SOIL UNIT

WEIGHT (PCF)

COHESION

(PSF)

SOIL ANGLE OF

FRICTION

(DEGREES)

EARTH PRESSURE

COEFFICIENTSOIL

CLASSIFICATION

PINELLAS COUNTY, FLORIDA

AREHNA Project No. B‐22‐007.03

Ka Kp

DEPTH

(FEET)

SPT "N" AVERAGE

(AUT0)

BORING

NUMBER

ELEVATION

(NAVD 88)

SPT‐01

SPT‐02

SPT‐03

SPT‐04

FIELD PROCEDURES

Standard Penetration Test (SPT) Borings

The SPT borings are performed in general accordance with ASTM D-1586, "Penetration Test and Split-Barrel

Sampling of Soils." A rotary drilling process is used and bentonite drilling fluid is circulated in the boreholes to stabilize the sides and flush the cuttings. At regular intervals, the drilling tools are removed and soil samples are obtained with a standard 2-feet long, 2-inch diameter split-tube sampler. The sampler is first seated 6 inches and then driven an additional foot with blows of a 140-pound hammer falling under its own weight a distance of 30 inches. The number of hammer blows required to drive the sampler the final foot is designated the "Penetration

Resistance." The penetration resistance, when properly interpreted, is an index to the soil strength and density.

LABORATORY PROCEDURES

Water Content

The water content is the ratio, expressed as a percentage, of the weight of water in a given mass of soil to the weight of the solid particles. This test is conducted in general accordance with AASHTO T-265/ASTM D-2974.

Percent Organics (Organic Loss on Ignition)

The amount of organic material in a sample is determined in this test. The sample is first dried and weighed, then ignited and reweighed. The amount of organic material is expressed as a percentage of the total dry weight of the sample prior to ignition. This test is conducted in general accordance with FM 1-T267.

Atterberg Limits (Plasticity)

A soil's Plasticity Index (PI) is the numerical difference between the Liquid Limit (LL) and the Plastic limit (PL). The LL is the moisture content at which the soil will flow as a heavy viscous fluid and is determined in general accordance with AASHTO T-89/ASTM D-4318. The PL is the moisture content at which the soil begins to crumble when rolled into a small thread and is also determined in general accordance with AASHTO T-90/ASTM D-4318.

Fines Content

In this test, the sample is dried and then washed over a No. 200 mesh sieve. The percentage of soil by weight passing the sieve is the percentage of fines or portion of the sample in the silt and clay size range. This test is conducted in general accordance with AASHTO T-11/ASTM D-1140.