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GFA INTERNATIONAL
FLORIDA’S LEADING ENGINEERING SOURCE
Report of Geotechnical Exploration
Watersong Way Three-Story Residence
5000 Watersong Way
Fort Pierce, Florida
December 21, 2020
GFA Project No. 3330.2000274.0000
For: Coastal Construction and Design, Inc.
Since 1988
Florida’s Leading Engineering Source
Environmental • Geotechnical • Construction Materials Testing • Threshold and Special Inspections • Plan Review & Code Compliance
607 NW Commodity Cove • Port St. Lucie, Florida 34986 • (772) 924-3575 • (772) 924-3580 (fax) • www.teamgfa.com
OFFICES THROUGHOUT FLORIDA
December 21, 2020
Mr. Mario Arbucci
Coastal Construction and Design, Inc.
4832 Watersong Way
Fort Pierce, Florida 34949
Subject: Report of Geotechnical Exploration
Watersong Way Three-Story Residence
5000 Watersong Way, Fort Pierce, Florida
GFA Project No. 3330.2000274.0000
Dear Mr. Arbucci:
GFA International, Inc. (GFA) has completed the subsurface exploration and geotechnical
engineering evaluation for the above referenced project in accordance with the geotechnical
and engineering service agreement for this project. The scope of services was completed in
accordance with our Geotechnical Engineering Proposal No. 20-4534.00 dated December 8,
2020, planned in conjunction with and authorized by you.
EXECUTIVE SUMMARY
The purpose of our subsurface exploration was to classify the nature of the subsurface soils and
general geomorphic conditions at the site and evaluate their impact upon the proposed
construction. This report contains the results of our subsurface exploration and our engineering
interpretations of these with respect to the project characteristics described to us, including
providing recommendations for site preparation and design of the foundation system.
Per our prior telephone discussions and email correspondence with you, GFA understands that
a new three-story residence is planned for construction at the referenced property. Since the
structure (or a portion thereof) will be located east of the Coastal Construction Control Line
(CCCL), a pile supported foundation is required. We have been provided with plans prepared
by James Bushouse, Inc. illustrating the location of the residence on the property. The plans
also indicate that the residential structure will be supported by 14-inch diameter augered cast-in-
place (ACIP) piles and grade beams. The piles have a design capacity of 30 tons.
The recommendations provided herein are based upon the above considerations. If the stated
conditions are incorrect or if project description is revised, please inform GFA so that we may
review our recommendations with respect to any modifications.
Two (2) standard penetration test (SPT) borings, advanced to a depth of approximately 40 feet
below the existing ground surface, were completed for this study. The subsurface soil conditions
encountered in the borings generally consisted of very loose to medium dense fine sand (SP),
fine sand with silt (SP-SM), and silty fine sand (SM) within the upper 18.5 feet of the soil profile.
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 2 of 10
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A seam of muck (PT) was also present from a depth of approximately 8.5 to 11.5 feet in boring
B-1. These soils were underlain by layers of medium dense to very dense fine sand (SP)
containing varying amounts of shell to the boring termination depths.
The results of the borings indicate that a foundation system consisting of ACIP piles and grade
beams will be suitable for the proposed residence. Axial compressive and tension capacities for
14-inch diameter ACIP piles having lengths of 25, 30, and 35 feet were developed for the
project. The results of our analysis are contained in Table 3.2.1 in Section 3.2 of this report.
Note that the pile installation lengths in the table are relative to the current ground surface. The
piles will be longer or shorter based on depth of fill added or other elevation adjustments.
Subgrade soils should be improved (densified) with compaction from the stripped grade prior to
constructing any ground supported/structural slabs. The top 2 feet below stripped grade should
be compacted to a minimum of 95 percent of modified Proctor (ASTM D 1557) maximum dry
density prior to placing fill to achieve final grade. Fill required to attain design grades should be
placed in 12-inch lifts and compacted to achieve the same criteria stated above.
Scour elevations used in pile capacity calculations are those provided by the Florida DEP for
coastal construction but may not be adequate for actual scour elevations exceeding the DEP
assumptions that may occur in hurricane events. Therefore, our analysis is limited to the DEP
scour elevation criteria. Additional scour analysis was not included in our scope of work.
We appreciate the opportunity to be of service to you during this phase of the project and look
forward to a continued association. Please do not hesitate to contact us if you have any
questions or comments, or if we may further assist you as your plans proceed.
Respectfully Submitted,
GFA International, Inc.
Florida Certificate of Authorization No. 4930
This item has been digitally signed and sealed by John Kent, P.E. 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.
John Kent, P.E. Erik Soderstrom, E.I.
Senior Project Engineer Geotechnical Department Manager
Florida Registration No. 63218
Distribution: Mr. Mario Arbucci – Coastal Construction and Design, Inc. 1 pdf
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 3 of 10
____________________________________________________________________________________
TABLE OF CONTENTS
1.0 INTRODUCTION ................................................................................................................. 4
1.1 Scope of Services ........................................................................................................... 4
1.2 Project Description .......................................................................................................... 4
2.0 OBSERVATIONS ................................................................................................................ 4
2.1 Site Description ............................................................................................................... 4
2.2 Field Exploration ............................................................................................................. 5
2.3 Visual Classification ........................................................................................................ 5
2.4 Geomorphic Conditions ................................................................................................... 5
2.5 Hydrogeological Conditions ............................................................................................. 6
3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS.............................................. 6
3.1 General ........................................................................................................................... 6
3.2 Pile Foundation Design ................................................................................................... 6
3.3 Pile Foundation Installation ............................................................................................. 8
3.4 Site Preparation .............................................................................................................. 8
3.5 Fill Placement and Compactioin ...................................................................................... 9
3.6 Quality Control and Vibration Monitoring ......................................................................... 9
4.0 REPORT LIMITATIONS .....................................................................................................10
5.0 BASIS FOR RECOMMENDATIONS ..................................................................................10
Appendix A - Vicinity Map
Appendix B - Test Location Plan
Appendix C - Notes Related to Borings
Appendix D - Log of Boring Records
Appendix E - Discussion of Soil Groups
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 4 of 10
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1.0 INTRODUCTION
1.1 Scope of Services
The objective of our geotechnical services was to collect subsurface data for the subject project,
summarize the test results, and discuss any apparent site conditions that may have
geotechnical significance for the planned construction. The following scope of services is
provided within this report:
1. Prepare logs depicting the subsurface soil conditions encountered in the borings.
2. Review the soil samples obtained during our field exploration for classification and additional
testing if necessary.
3. Evaluate the existing soil conditions found during our exploration with respect to ACIP pile
foundation support of the proposed residential structure.
4. Provide recommendations with respect to ACIP pile foundation support of the structure,
including pile diameter, capacity, length, and other pile design and installation criteria.
5. Provide recommendations for site preparation and earthwork construction.
1.2 Project Description
Per our prior telephone discussions and email correspondence with you, GFA understands that
a new three-story residence is planned for construction at the referenced property. Since the
structure (or a portion thereof) will be located east of the Coastal Construction Control Line
(CCCL), a pile supported foundation is required. We have been provided with plans prepared
by James Bushouse, Inc. illustrating the location of the residence on the property. The plans
also indicate that the residential structure will be supported by 14-inch diameter augered cast-in-
place (ACIP) piles and grade beams. The piles have a design capacity of 30 tons.
The recommendations provided herein are based upon the above considerations. If the stated
conditions are incorrect or if project description is revised, please inform GFA so that we may
review our recommendations with respect to any modifications.
2.0 OBSERVATIONS
2.1 Site Description
At the time of our field exploration, the majority of the property was generally grassy with some
miscellaneous vegetation. Undeveloped residential lots were located immediately north and
south of the site, the Atlantic Ocean to the east, and Watersong Way and Highway A1A to the
west.
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 5 of 10
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2.2 Field Exploration
Two (2) standard penetration test (SPT) borings, advanced to a depth of approximately 40 feet
below the existing ground surface, were completed for this study. The boring depths were
established based upon our knowledge of vicinity soils and confined to the zone of soil likely to
be influenced by the foundation construction. The approximate boring locations are illustrated
on the Test Location Plan in in Appendix B.
The Standard Penetration Tests (SPT) were performed in general accordance with ASTM D
1586, “Standard Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of
Soils.” The SPT test procedure consists of driving a 1.4-inch I.D. split-barrel sampler into the
soil profile using a 140-pound hammer falling 30 inches. The number of blows per foot, for the
second and third 6-inch increment, is referred to as the N-value. The N-value has been
empirically correlated with various soil properties and provides an indication of soil strength.
Site specific survey staking for the borings was not provided for our field exploration. The
indicated depth and location of the borings were approximated based upon existing grade and
estimated distances and relationships to the adjacent properties and Watersong Way.
2.3 Visual Classification
Soil samples recovered from our field exploration were returned to our laboratory where they
were visually classified by a geotechnical engineer in general accordance with the Unified Soil
Classification System (ASTM D 2487). After reviewing the samples, no laboratory testing was
deemed necessary. The samples will be retained in our laboratory for 30 days and then
discarded unless we are notified otherwise in writing.
The recovered samples were not evaluated, either visually or analytically, for chemical
composition or environmental hazards. GFA would be pleased to perform these services for an
additional fee, if required.
2.4 Geomorphic Conditions
The geology of the site as mapped on the USDA Soil Survey website consists of Canaveral fine
sand, 0 to 5 percent slopes (10). These are sandy soils and organic soils are not indicated.
The Soil Survey generally extends to a maximum depth of 80 inches below ground surface and
is not indicative of deeper soil conditions.
The boring logs resulting from our field exploration are presented in Appendix D - Log of Boring
Records. The logs contain the soil descriptions and the standard penetration test (SPT) N-
values values logged during the drilling and sampling activities. Note that the soil borings reflect
information from the specific boring locations only and that soil conditions may vary between the
strata interfaces indicated on the logs. The soil classifications and descriptions shown on the
logs are generally based upon visual characterizations of the recovered samples using the
Unified Soil Classification System. See Appendix E - Discussion of Soil Groups, for a detailed
description of various soil groups.
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 6 of 10
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The subsurface soil conditions encountered in the borings generally consisted of very loose to
medium dense fine sand (SP), fine sand with silt (SP-SM), and silty fine sand (SM) within the
upper 18.5 feet of the soil profile. A seam of muck (PT) was also present from a depth of
approximately 8.5 to 11.5 feet in boring B-1. These soils were underlain by layers of medium
dense to very dense fine sand (SP) containing varying amounts of shell to the boring
termination depths.
2.5 Hydrogeological Conditions
On the date of our field exploration (December 17, 2020), groundwater was recorded at
approximate depths of 6 and 6.3 feet at the boring locations. Note that the groundwater table
will fluctuate seasonally depending upon local rainfall and other site specific and/or local factors,
including tidal influences from the Atlantic Ocean. Brief ponding of stormwater may occur
across the site after heavy or extended rainfall events.
No additional evaluation was included in our scope of work in relation to the wet seasonal high
groundwater table or any existing well fields in the vicinity. Well fields may influence water table
levels and cause significant fluctuations. If a more comprehensive water table analysis is
necessary, please contact our office for additional guidance.
3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS
3.1 General
Our geotechnical engineering evaluation of the site and subsurface conditions at the property,
with respect to the planned construction, and our recommendations for site preparation and
foundation support, are based upon (1) our site observations, (2) the field data obtained, and (3)
our understanding of the project information and structural conditions as presented in this
report. If the stated conditions are incorrect, or if the project description is revised, please
inform GFA so that we may review our recommendations with respect to any modifications.
We note that the applicability of geotechnical recommendations is very dependent upon project
characteristics, specifically (1) improvement locations, (2) grade alterations, (3) and actual
applied structural loads. For that reason, GFA must be provided with and review the preliminary
and final site and grading plans, and structural design loads to validate all recommendations
provided in this report. Without performing this review, our recommendations should not be
relied upon for final design or construction of any site improvements.
3.2 Pile Foundation Design
Since the residence (or portions thereof) will be located east of the Coastal Construction Control
Line (CCCL), a pile supported foundation is required. GFA considered the following design
criteria to develop pile foundation recommendations for the proposed residence:
1. For CCCL construction, the FDEP has established a 100-year storm elevation (bottom of
lowest structural member) of 17.0 to 17.9 feet NGVD (15.5 to 16.4 NAVD), depending on
location, for structures within St. Lucie County.
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 7 of 10
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2. For CCCL construction, the FDEP has established a 100-year storm erosion elevation
(design scour elevation) of 2.7 NGVD (1.2 NAVD) for all of St. Lucie County.
3. A loss of soil support between the bottom of lowest structural member and the design
scour elevation of 2.7 NGVD (1.2 NAVD) was considered in the pile capacity analyses.
4. We assume that fill will be placed to achieve final (or near final) grade before installing
the pile foundations. The residence will utilize typical construction and be supported on
columns terminating on pile caps slightly below the ground floor elevation (9.5 NGVD,
8.0 NAVD). The top of piles (bottom of pile caps) will be approximately elevation 7.5
NGVD (6.0 NAVD).
The soil profile revealed by the borings is compatible with supporting the residential structure
upon a deep foundation system consisting of 14-inch diameter augered-cast-in-place (ACIP)
piles and grade beams. ACIP pile design should be in accordance with the applicable sections
of the 2017 Florida Building Code, Sixth Edition, the latest edition of the Deep Foundations
Institute’s Augered Cast-In-Place Piles Manual, and other applicable federal, state, and local
requirements.
The results of our ACIP pile capacity analysis are summarized in Table 3.2.1 below. The
evaluations were performed using the commercially available ALLPILE 7.0 software using a
factor of safety of 2.0.
Table 3.2.1 - ACIP Pile Design Recommendations for 14-Inch Diameter Piles
Nominal Pile
Diameter (in)
Pile Top
Elevation
Recommended
Pile Tip
Elevation
Pile
Length
(ft)
Maximum Allowable
Pile Compression
Capacity (Tons)
Pile Allowable
Tension
Capacity (Tons)
Grout
Strength
(psi)
14 Unknown Unknown 25 30 5.4 5,000
14 Unknown Unknown 30 33 7.3 5,000
14 Unknown Unknown 35 28 9.2 5,000
The design pile depths in the above table are based on installing the piles at the site grade
existing at the boring locations at the time of drilling. Any fill required to raise the site to achieve
design grade will result in the piles being longer based upon the thickness of the placed fill. If
piles having depths and/or capacities other than those presented in the above table are desired,
GFA will be pleased to provide further recommendations upon request.
The following notes are also applicable to the ACIP pile design:
1. GFA assumed that the piles will have a minimum of 1 percent steel reinforcement for the
analysis. ACIP piles should be reinforced over their entire length for tension capacity.
The reinforcement should be as designed by the project Structural Engineer.
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 8 of 10
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2. Structural stresses in the piles may impose a more severe limitation on the design
capacity. Therefore, we recommend the allowable stresses be verified for the selected
pile section by the project Structural Engineer.
3. The pile reinforcement should be sufficiently embedded in the pile cap to afford a fixed
end connection, as required.
3.3 Pile Foundation Installation
Pile installation should be in accordance with the applicable sections of the 2017 Florida
Building Code, Sixth Edition and other applicable federal, state, and local requirements. In
addition, piles should be installed in accordance with the following:
1. Pile Length - The proposed piles should be installed as determined by the inspecting
Geotechnical Engineer.
2. Spacing - Piles installed in groups should be spaced at a center-to-center distance of not
less than 3 pile diameters.
3. Plan Location - The center of the top of any pile at cut-off should be displaced laterally
no more than 3 inches from the position shown on the plans. This applies to both single
piles and piles installed in groups.
4. Vertical Alignment - The vertical alignment of the piles should not deviate from the plumb
by more than 1/4 inch per foot of length.
5. Reinforcing Cage Positioning - The top of the reinforcing cages installed in the piles
should not be more than 6 inches above and no more than 3 inches below the positions
shown in the plans. The reinforcing cages should be positioned concentrically within the
grouted pile shaft. The grout cover over longitudinal reinforcing bars should not be less
than 3 inches. Reinforcing centralizers should be placed at maximum spacing of 15 feet
at the lower portion of the pile and at 5 feet from the top of the cage.
6. Adjacent Piles - A minimum elapsed time of 12 hours should be specified for the
installation of piles located within 5 feet, center-to-center, of each other.
7. Grout Factor - The minimum acceptable grout factor (i.e. actual grout volume divided by
the theoretical grout volume) should be 1.1.
3.4 Site Preparation
Initial site preparation should consist of removing all surface vegetation, near surface roots, and
other deleterious materials within, and to five (5) feet beyond, the perimeter of the footprint of
the planned construction. Foundations and the below grade remains of former structures that
are within the footprint of the new construction should also be removed. Similarly, utility lines
should be removed or properly abandoned so that they will not adversely impact new overlying
structures.
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 9 of 10
____________________________________________________________________________________
3.5 Fill Placement and Compaction
Prior to initiating fill placement, the stripped surface should be compacted until the upper 2 feet
of soil achieves at least 95 percent of modified Proctor maximum dry density (ASTM D 1557).
We recommend using a steel drum vibratory roller having sufficient static weight to achieve the
required compaction. Density tests should be performed on the compacted surface at a
frequency of not less than one test per 2,500 square feet, or a minimum of three (3) tests,
whichever is greater. The density tests should be performed using either the nuclear method
(ASTM D 6839) or the sand cone method (ASTM D 1556). Hand Cone Penetrometer (HCP)
tests may also be performed to evaluate soil density.
Fill required for the project should be inorganic (i.e., contain less than 5 percent by weight
organic material) and classified as SP, SW, GP, GW, SP-SM, SW-SM, GW-GP, or GP-GM.
GFA does not recommend using fill material having silt/clay-size soil fines contents
exceeding 12 percent. In general, fill required to attain design grades should be placed in
maximum 12-inch thick loose lifts and compacted to at least 95 percent of modified Proctor
maximum dry density (ASTM D 1557). Each lift of fill should be compacted and tested prior to
the placement of the next lift. Density tests should be performed within the fill at the same
frequency noted above.
Following installation of the ACIP piles and construction of the pile caps and grade beams, the
areas next to the pile caps and grade beams will require backfilling. This fill should be placed in
maximum 8-inch thick loose lifts and compacted to at least 95 percent of modified Proctor
maximum dry density (ASTM D 1557). The compaction should be performed using portable
equipment, such as vibratory sleds, jumping jacks, or walk-behind rollers.
3.6 Quality Control and Vibration Monitoring
We strongly recommend that a GFA representative be on site throughout the ACIP pile
installation. This is necessary to determine if the piles are being installed in accordance with the
project plans and specifications, provide an accurate record of the installation, and provide an
opportunity to correct any anomalous conditions during the pile placement work. In addition, the
grout mix used to form the piles should be sampled and tested for strength on a regular basis.
The construction will be close to existing residential structures and a roadway that could be
susceptible to damage from vibrations generated at the site during site preparation and
foundation installation. GFA recommends that these structures and other bordering landmarks
be monitored using a seismograph to determine the extent of vibration absorption they are
experiencing during all aspects of construction. The seismograph used for monitoring at the site
should have the capability to measure ground velocities along vertical, transverse, and
longitudinal axes. The project Structural Engineer should establish allowable ground velocities
that the bordering facilities can safely withstand without incurring damage. A proposal for GFA
personnel to provide the vibration monitoring during construction will be provided upon request.
Watersong Way Three-Story Residence Geotechnical Exploration Report
5000 Watersong Way, Fort Pierce, Florida December 21, 2020
GFA Project No. 3330.2000274.0000 Page 10 of 10
____________________________________________________________________________________
4.0 REPORT LIMITATIONS
This consulting report has been prepared for the exclusive use of Coastal Construction and
Design, Inc. and members of the design team for the proposed new residence located at 5000
Watersong Way in Fort Pierce, Florida. This report has been prepared in accordance with
generally accepted local geotechnical engineering practices; no other warranty is expressed or
implied.
The evaluation submitted in this report is based in part upon the data collected during a field
exploration. However, the nature and extent of variations throughout the subsurface profile may
not become evident until construction. If variations then appear evident, it may be necessary to
reevaluate the information and professional opinions provided in this report. In the event
changes are made in the nature, design, or location of the proposed residence, the evaluation
and opinions contained in this report should not be considered valid unless the changes are
reviewed, and conclusions modified or verified in writing by GFA.
GFA should be provided the opportunity to review the final foundation plans and specifications
to determine if GFA’s recommendations have been properly interpreted, communicated, and
implemented. If GFA is not afforded the opportunity to participate in construction related
aspects of foundation installation as recommended in this report or any report addendum, GFA
cannot accept responsibility for the interpretation of our recommendations made in this report or
in a report addendum for foundation performance.
Scour elevations used in pile capacity evaluations are those provided by the Florida DEP for
coastal construction but may not be adequate for actual scour elevations exceeding the DEP
assumptions that may occur in hurricane events. Therefore, our analysis is limited to the DEP
scour elevation criteria. Additional scour analysis was not included in our scope of work.
5.0 BASIS FOR RECOMMENDATIONS
The analysis and recommendations submitted in this report are based on the data obtained
from the borings performed at the locations indicated on the Test Location Plan in Appendix B.
This report does not reflect any variations which may occur between or away from the borings.
While the borings are representative of the subsurface conditions at their locations and vertical
reaches, local variations characteristic of the subsurface soils within the region are anticipated
and may be encountered. The delineation between soil types shown on the boring logs is
approximate and the descriptions represent our interpretation of the subsurface conditions at
the designated boring locations on the specific date drilled.
Any third-party reliance of this geotechnical report or parts thereof is strictly prohibited without
the expressed written consent of GFA International, Inc. The applicable SPT methodology
(ASTM D 1586) used in performing our borings, and for determining penetration resistance, is
specific to the sampling tools utilized and does not reflect the ease or difficulty to advance other
tools or materials.
Appendix A - Vicinity Map
Site Vicinity Map
5000 Watersong Way Residence
5000 Watersong Way, Fort Pierce, Florida
PROJECT NO: 3330.2000274.0000 DRAFTED BY: JR REVIEWED BY: JK DATE: 12/21/2020
gfhgfghfgh
N
Site Location
Appendix B - Test Location Plan
Test Location Plan
5000 Watersong Way Residence
5000 Watersong Way, Fort Pierce, Florida
PROJECT NO: 3330.2000274.0000 DRAFTED BY: JR REVIEWED BY: JK DATE: 12/21/2020
gfhgfghfgh
N Legend
Approximate 40’ Standard Penetration Test Boring Locations
B-1
B-2
Appendix C - Notes Related to Borings
NOTES RELATED TO BORING RECORDS AND GENERALIZED SUBSURFACE PROFILES
1. Groundwater levels (if encountered) were recorded either during or following the boring completion on
the date indicated. Fluctuations in groundwater levels are common - see the report text for a discussion.
2. The boring locations were identified in the field by estimated distances and offsets from existing reference
marks and/or other site landmarks.
3. The completed boreholes were backfilled to adjacent site grade using drilling spoils and patched with
asphalt cold mix in pavement areas.
4. The Log of Boring records represent our interpretation of soil conditions based on visual classification of
the soil samples recovered from the borings.
5. The Log of Boring records are subject to the limitations, conclusions, and recommendations presented in
the report text.
6. The Standard Penetration Test (SPT) N-values contained on the Log of Boring records refer to the total
blow counts of a 140-pound drop hammer falling 30 inches required to drive a split-barrel sampler a total
distance of 12 inches into soil strata at specific depth intervals.
7. The Hand Cone Penetrometer (HCP) values contained on Log of Boring records and the Cone
Penetration Test (CPT) values contained on the Cone Penetration Sounding logs refer to the cone tip
resistance recorded when pushing the cone tip into the soil strata at specific depth intervals.
8. The soil and/or rock strata interfaces shown on the Log of Boring records are approximate and may vary
from those shown on the logs. The soil and/or rock descriptions shown on the Log of Boring records refer
to conditions at the specific location tested. Soil/rock conditions may vary between test locations.
9. Relative density for coarse-grained soils (sands/gravels) and consistency for fine-grained soils (silts/clays)
are described as follows:
Coarse Grained Soils (Sands and Gravels) Fine Grained Soils (Silts and Clays)
SPT N-Value HCP Value (kg/cm2) CPT Value (tsf) Relative Density SPT N-Value HCP Value (kg/cm2) CPT Value (tsf) Consistency
0-4 0-16 0-20 Very Loose 0-2 0-20 0-3 Very Soft 5-10 17-36 21-40 Loose 3-4 21-35 4-6 Soft
11-30 37-116 41-120 Med. Dense 5-8 >35 7-12 Firm
31-50 117-196 121-200 Dense 9-15 13-25 Stiff
>50 > 196 >200 Very Dense 16-30 26-50 Very Stiff
>30 >50 Hard
10. Grain size descriptions are as follows:
Description Particle Size Limits
Boulder Greater than 12 inches Cobble 3 to 12 inches
Coarse Gravel 3/4 to 3 inches
Fine Gravel No. 4 sieve to 3/4 inch
Coarse Sand No. 10 to No. 4 sieve
Medium Sand No. 40 to No. 10 sieve
Fine Sand No. 200 to No. 40 sieve
Fines (Silt/Clay) Smaller than No. 200 sieve
11. Definitions for modifiers used in soil/rock descriptions:
Proportion Modifier Approximate Root Diameter Modifier
<5% Trace Less than 1/32" Fine roots
5% to 12% Little 1/32" to 1/4” Small roots
12% to 30% Some 1/4” to 1" Medium roots
30% to 50% And Greater than 1" Large roots
Organic Soils: Soils containing vegetative tissue in various stages of decomposition having a fibrous to amorphous
texture. Usually having a dark brown to black color and an organic odor.
Organic Content Modifiers: <25%: Slightly to Highly Organic; 25% to 75%: Muck; >75%: Peat
Appendix D - Log of Boring Records
4
12
11
12
9
10
11
10
4
4
6
5
3
2
1
1
1
2
1
2
1
2
3
5
5
6
6
17
24
30
Topsoil (.5")
Light brown fine sand, trace shell (SP)
Gray fine sand, little shell (SP)
Gray fine sand with silt (SP-SM)
Gray fine sand, little plastic debris and shell (SP)
Dark brown muck (PT)
Gray silty fine sand (SM)
Gray fine sand, little silt (SP)
Gray fine sand, little shell (SP)
0.1
2.0
4.0
7.0
8.5
10.5
13.5
15.0
1
2
3
4
5
6
7
8
23
21
10
3
3
5
12
54
HAMMER TYPE
HOLE DIAMETER 3 in
DRILLER JB/RV
DRILL RIG GeoProbe
METHOD SPT
HOLE DEPTH 40 ft
DATE STARTED 12/17/20 COMPLETED 12/17/20
AT TIME OF DRILLING 6.00 ft
NOTE:
GROUND WATER LEVEL:
DRILLING CONTRACTOR GFA International Inc.
LATITUDE LONGITUDE
SAMPLEGRAPHICLOGBLOWCOUNTSMATERIAL DESCRIPTION
SAMPLENUMBERN VALUE(Continued Next Page)
PROJECT NUMBER 3330.2000274.0000 PROJECT LOCATION 5000 Watersong Way, Fort Pierce, Florida
PROJECT NAME 5000 Watersong Way Residence
LOG OF BORING B-1
PAGE 1 OF 2
CLIENT Coastal Construction and Design, Inc.DEPTH(ft)5
10
15
20 MOISTURECONTENT (%)FINESCONTENT (%)ORGANICCONTENT (%)SPT LOGS - GFA DATA TEMPLATE.GDT - 12/21/20 11:49 - Z:\PROJECTS\_UES PROJECT SETUP\3330.2000274.0000 - 5000 WATERSONG WAY - GEO\20-4534.00 - 5000 WATERSONG WAY RESIDENCE - GEO\GEO\APPENDICES NORMAL\SPT LOGS.GPJGFA International, Inc.
607 NW Commodity Cove
Port Saint Lucie, Florida 34986
(772) 924-3575
21
24
26
17
21
30
12
14
16
11
12
15
Gray fine sand, little shell (SP) (continued)
Gray fine sand, some shell (SP)
Gray fine sand, little shell (SP)
Gray fine sand, trace shell (SP)
Bottom of borehole at 40.0 feet.
23.5
33.5
38.5
40.0
9
10
11
12
50
51
30
27SAMPLE GRAPHICLOGBLOWCOUNTSMATERIAL DESCRIPTION
SAMPLENUMBERN VALUEPROJECT NUMBER 3330.2000274.0000 PROJECT LOCATION 5000 Watersong Way, Fort Pierce, Florida
PROJECT NAME 5000 Watersong Way Residence
LOG OF BORING B-1
PAGE 2 OF 2
CLIENT Coastal Construction and Design, Inc.DEPTH(ft)25
30
35
40 MOISTURECONTENT (%)FINESCONTENT (%)ORGANICCONTENT (%)SPT LOGS - GFA DATA TEMPLATE.GDT - 12/21/20 11:49 - Z:\PROJECTS\_UES PROJECT SETUP\3330.2000274.0000 - 5000 WATERSONG WAY - GEO\20-4534.00 - 5000 WATERSONG WAY RESIDENCE - GEO\GEO\APPENDICES NORMAL\SPT LOGS.GPJGFA International, Inc.
607 NW Commodity Cove
Port Saint Lucie, Florida 34986
(772) 924-3575
3
10
10
14
6
10
11
13
6
6
7
9
3
4
4
5
4
4
3
3
3
3
1
10
21
20
Light brown fine sand, little silt (SP)
Gray fine sand, little shell (SP)
Gray fine sand, trace shell (SP)
Gray silty fine sand, trace shell (SM)
Gray fine sand, trace shell (SP)
3.0
4.0
13.5
18.5
1
2
3
4
5
6
7
20
21
13
8
7
4
41
HAMMER TYPE
HOLE DIAMETER 3 in
DRILLER JB/RV
DRILL RIG GeoProbe
METHOD SPT
HOLE DEPTH 40 ft
DATE STARTED 12/17/20 COMPLETED 12/17/20
AT TIME OF DRILLING 6.30 ft
NOTE:
GROUND WATER LEVEL:
DRILLING CONTRACTOR GFA International Inc.
LATITUDE LONGITUDE
SAMPLEGRAPHICLOGBLOWCOUNTSMATERIAL DESCRIPTION
SAMPLENUMBERN VALUE(Continued Next Page)
PROJECT NUMBER 3330.2000274.0000 PROJECT LOCATION 5000 Watersong Way, Fort Pierce, Florida
PROJECT NAME 5000 Watersong Way Residence
LOG OF BORING B-2
PAGE 1 OF 2
CLIENT Coastal Construction and Design, Inc.DEPTH(ft)5
10
15
20 MOISTURECONTENT (%)FINESCONTENT (%)ORGANICCONTENT (%)SPT LOGS - GFA DATA TEMPLATE.GDT - 12/21/20 11:49 - Z:\PROJECTS\_UES PROJECT SETUP\3330.2000274.0000 - 5000 WATERSONG WAY - GEO\20-4534.00 - 5000 WATERSONG WAY RESIDENCE - GEO\GEO\APPENDICES NORMAL\SPT LOGS.GPJGFA International, Inc.
607 NW Commodity Cove
Port Saint Lucie, Florida 34986
(772) 924-3575
21
38
39
14
50
9
13
13
10
11
13
Gray fine sand, trace shell (SP) (continued)
Gray fine sand, little shell (SP)
Gray fine sand, trace shell (SP)
Bottom of borehole at 40.0 feet.
23.5
28.5
40.0
8
9
10
11
77
50
26
24SAMPLE GRAPHICLOGBLOWCOUNTSMATERIAL DESCRIPTION
SAMPLENUMBERN VALUEPROJECT NUMBER 3330.2000274.0000 PROJECT LOCATION 5000 Watersong Way, Fort Pierce, Florida
PROJECT NAME 5000 Watersong Way Residence
LOG OF BORING B-2
PAGE 2 OF 2
CLIENT Coastal Construction and Design, Inc.DEPTH(ft)25
30
35
40 MOISTURECONTENT (%)FINESCONTENT (%)ORGANICCONTENT (%)SPT LOGS - GFA DATA TEMPLATE.GDT - 12/21/20 11:49 - Z:\PROJECTS\_UES PROJECT SETUP\3330.2000274.0000 - 5000 WATERSONG WAY - GEO\20-4534.00 - 5000 WATERSONG WAY RESIDENCE - GEO\GEO\APPENDICES NORMAL\SPT LOGS.GPJGFA International, Inc.
607 NW Commodity Cove
Port Saint Lucie, Florida 34986
(772) 924-3575
Appendix E - Discussion of Soil Groups
DISCUSSION OF SOIL GROUPS
COARSE GRAINED SOILS
General. A soil is classified as coarse-grained if more than 50 percent of a representative
sample of the material is retained on the No. 200 sieve.
GW and SW Groups. These groups comprise well-graded gravelly and sandy soils
containing little or no plastic fines (less than 5 percent passing the No. 200 sieve). The low
fines content does not noticeably change the shear strength characteristics of these soils
and does not interfere with their free-draining characteristics.
GP and SP Groups. Poorly graded gravels and sands containing little or no plastic fines
(less than 5 percent passing the No. 200 sieve) are in the GP and SP groups. The
materials can be called uniform gravels, uniform sands, or non-uniform mixtures of very
coarse materials and very fine sand, with intermediate sizes lacking (sometimes called
skip-graded, gap-graded, or step-graded). This last group often results from borrow pit
excavation in which gravel and sand layers are mixed.
GM and SM Groups. In general, the GM and SM groups comprise gravels or sands with
fines (more than 12 percent passing the No. 200 sieve) having little or no plasticity. The
plasticity index and liquid limit of soils in these groups plot below the “A” line on the
plasticity chart. The gradation of the material is not considered significant and both well
and poorly graded materials are included.
GC and SC Groups. In general, the GC and SC groups comprise gravelly or sandy soils
containing fines (more than 12 percent passing the No, 200 sieve) having plasticity
characteristics. The plasticity index and liquid limit of soils in these groups plot above the
“A” line on the plasticity chart.
FINE GRAINED SOILS
General. A soil is classified as fine-grained if more than 50 percent of a representative
sample of the material passes the No. 200 sieve.
ML and MH Groups. These groups comprise inorganic silts (ML) and elastic silts (MH)
having either low (L) or high (H) liquid limits, respectively. ML soils have a liquid limit of
less than 50 while MH soils have a liquid limit of 50 and greater. Silts and elastic silts can
also contain varying amounts of sand and gravel. Also included in this group are loess
sediments and rock flours.
CL and CH Groups. These groups comprise low plasticity (lean) clays (CL) and medium
to high plasticity (fat) clays (CH) having either low (L) or high (H) liquid limits, respectively.
CL soils have a liquid limit of less than 50 while CH soils have a liquid limit of 50 and
greater. The low plasticity clays can also be sandy clays or silty clays. The moderate to
high plasticity clays can also be sandy clays and include some volcanic clays.
OL and OH Groups. These groups comprise organic silts and clays. The soils are
characterized by the presence of organic odor and/or dark color. The OL and OH soils
are differentiated by determining and comparing their liquid limit values before and after
oven drying representative soil samples.
HIGHLY ORGANIC SOILS
The highly organic soils are usually very soft and compressible and have undesirable
construction characteristics. Particles of leaves, grasses, branches, or other fibrous
vegetative matter are common components of these soils. They are not subdivided and
are classified into one group with the symbol PT. Peat humus and swamp soils with a
highly organic texture are typical soils of the group.