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Geotechnical Exploration Report
Lot A-3 Residence
10751 South Ocean Drive, Jensen Beach, Florida
March 16, 2020
GFA Project No. 20-8566.00
Prepared for: JWN Builders, LLC
Since 1988
Florida’s Leading Engineering Source
Environmental • Geotechnical • Construction Materials Testing • Threshold and Special Inspections • Plan Review & Code Compliance
March 16, 2020
Mr. James Newman
JWN Builders, LLC
1701 SE Carvalho Street
Port St. Lucie, Florida 34983
RE: Geotechnical Exploration Report
Lot A-3 Residence
10751 South Ocean Drive, Jensen Beach, Florida
GFA Project No. 20-8566.00
Dear Mr. Newman:
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. 20-8566.00 dated February 7, 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 foundation design and site preparation.
Per our prior telephone discussions and email correspondence with you, GFA understands the
project consists of a new single-story residence located at 10751 South Ocean Drive (Lot A-3) in
Jensen Beach, Florida. At this time, no site or house plans are available.
Specific design loads have not been provided to GFA. For the foundation recommendations
presented in this report, we assumed a maximum wall loading of 3 kips per linear foot and a
maximum column load of 35 kips.
The recommendations provided herein are based upon the above considerations. 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.
Two (2) standard penetration test (SPT) borings, advanced to an approximate depth of 15 feet
below the existing ground surface, were completed for this study. The subsurface soil conditions
encountered at the boring locations generally consisted of alternating layers of very loose to
dense fine sand (SP) containing varying amounts of shell to the boring termination depths.
Lot A-3 Residence Geotechnical Exploration Report
10751 S Ocean Drive, Jensen Beach, Florida March 16, 2020
GFA Project No.: 20-8566.00
Considering the results of our field exploration program, the subsurface soil conditions at the
project site are generally favorable for support of the proposed structure on shallow foundations.
A maximum allowable soil bearing pressure of 2,500 psf may be used for foundation design.
The subgrade soils should be improved (densified) with compaction from the stripped grade prior
to constructing the building pad. Prior to placing fill to achieve final grade, the upper 2 feet of
soil below stripped grade should be compacted to a minimum of 95 percent maximum dry
density as determined by the modified Proctor test (ASTM D 1557). Fill (including stem wall
backfill) should be placed in 12-inch thick lifts and compacted to achieve a minimum 95 percent
modified Proctor maximum dry density. After completing the footing excavations, the bearing
subgrade to a depth of 2 feet should be compacted to not less than 95 percent modified Proctor
maximum dry density.
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. Khaled Abdelli
Senior Project Engineer Project Manager
Florida Registration No. 63218
Distribution: Mr. James Newman – JWN Builders, LLC 1 pdf
TABLE OF CONTENTS
1.0 INTRODUTION ...............................................................................................................................................1
1.1 SCOPE OF SERVICES .......................................................................................................................................1
1.2 PROJECT DESCRIPTION ...................................................................................................................................1
2.0 OBSERVATIONS ...........................................................................................................................................1
2.1 SITE DESCRIPTION ..........................................................................................................................................1
2.2 FIELD EXPLORATION ........................................................................................................................................1
2.3 VISUAL CLASSIFICATION ..................................................................................................................................2
2.4 GEOMORPHIC CONDITIONS ..............................................................................................................................2
2.5 HYDROGEOLOGICAL CONDITIONS .....................................................................................................................3
3.0 ENGINEERING EVALUATION AND PRELIMINARY RECOMMENDATIONS ............................................3
3.1 GENERAL ........................................................................................................................................................3
3.2 SITE PREPARATION .........................................................................................................................................3
3.3 VIBRATION MONITORING ..................................................................................................................................4
3.4 DESIGN OF FOOTINGS......................................................................................................................................4
3.5 SETTLEMENT ESTIMATES .................................................................................................................................5
3.6 GROUND FLOOR SLABS ...................................................................................................................................5
4.0 REPORT LIMITATIONS .................................................................................................................................6
5.0 BASIS FOR RECOMMENDATIONS .............................................................................................................6
Appendices
Appendix A - Vicinity Map
Appendix B - Test Location Plan
Appendix C - Notes Related to Boring Records
Appendix D - Log of Boring Records
Appendix E - Discussion of Soil Groups
Lot A-3 Residence Geotechnical Exploration Report
10751 S Ocean Boulevard, Jensen Beach, Florida March 16, 2020
GFA Project No.: 20-8566.00 Page 1 of 6
1.0 INTRODUTION
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 building construction. The following scope of services is provided within this report:
1. Prepare boring logs depicting the subsurface soil conditions encountered during our field
exploration.
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 foundation support
for the proposed structure.
4. Provide recommendations with respect to foundation support of the structure, including foundation
type, maximum allowable soil bearing capacity, and bearing elevations.
5. Provide site preparation criteria for the proposed construction.
1.2 Project Description
Per our prior telephone discussions and email correspondence with you, GFA understands the project
consists of a new single-story residence located at 10751 South Ocean Drive (Lot A-3) in Jensen
Beach, Florida. At this time, no site or house plans are available.
Specific design loads have not been provided to GFA. For the foundation recommendations presented
in this report, we assumed a maximum wall loading of 3 kips per linear foot and a maximum column
load of 35 kips.
The recommendations provided herein are based upon the above considerations. 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.
2.0 OBSERVATIONS
2.1 Site Description
At the time of our field exploration, the site was generally flat. The elevation was approximately the
same as the adjacent roadway and adjacent properties.
2.2 Field Exploration
Two (2) standard penetration test (SPT) borings, advanced to an approximate depth of 15 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
planned construction. The locations of the borings are illustrated in Appendix B - Test Location Plan.
Lot A-3 Residence Geotechnical Exploration Report
10751 S Ocean Boulevard, Jensen Beach, Florida March 16, 2020
GFA Project No.: 20-8566.00 Page 2 of 6
The Standard Penetration Tests (SPT) were performed in general accordance with ASTM D 1586,
“Penetration Test 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.
The upper 4 feet of the borings were advanced by hand augering due to potential buried utility line
conflicts. The augered portion of the SPT borings were performed in general accordance with ASTM
D 1452, “Practice for Soil Investigation and Sampling by Auger Borings.” Hand Cone Penetrometer
(HCP) tests were conducted at one-foot depth intervals in the auger borings. The HCP test, in
conjunction with information about the soil type, is empirically correlated to the relative density of
subsurface soils.
Site specific survey staking of the borings was not provided for our field exploration. The indicated
depth and location of each boring was approximated based upon existing grade at the time of drilling
and estimated distances and relationships to the adjacent roadway and properties.
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). The samples will be retained in our laboratory for 30 days from the date of
this report 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 will 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 Arents, 0 to 5 percent
slopes (4). These are sandy soils and organic soils are not indicated. However, since Arents are
areas where the soils have been generally altered by grading, shaping, and covered with fill, the soils
can be variable. Note that the Soil Survey generally extends to a maximum depth of 80 inches below
ground surface and is not indicative of deeper soil conditions.
Boring logs resulting from our field exploration are presented in Appendix D - Log of Boring Records.
The boring logs contain the soil descriptions, the standard penetration test (SPT) N-values, and the
hand cone penetrometer (HCP) values logged during the drilling and sampling activities. Note that the
soil boring data reflect information from a specific test location only and the 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.
The subsurface soil conditions encountered at the boring locations generally consisted of alternating
layers of very loose to dense fine sand (SP) containing varying amounts of shell to the boring
termination depths.
Lot A-3 Residence Geotechnical Exploration Report
10751 S Ocean Boulevard, Jensen Beach, Florida March 16, 2020
GFA Project No.: 20-8566.00 Page 3 of 6
2.5 Hydrogeological Conditions
On the date of our field exploration (March 2, 2020), groundwater was encountered at an average depth
of approximately 4.1 feet below the ground surface 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 adjacent Jensen Beach to Jupiter Inlet Aquatic Preserve. 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 PRELIMINARY 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 Site Preparation
GFA recommends the following compaction requirements for this project:
Proof Roll ............................................................... 95 percent of modified Proctor
Building Pad Fill ..................................................... 95 percent of modified Proctor
Footings ................................................................. 95 percent of modified Proctor
The compaction percentages presented above are based upon the maximum dry density as determined
by the modified Proctor test (ASTM D 1557). All density tests should be performed to a depth of 2
feet below stripped surface and bottom of footings. Density testing should be performed using
either the nuclear method (ASTM D 6938) or the sand cone method (ASTM D 1556). Hand Cone
Penetrometer (HCP) tests can also be performed to evaluate compaction.
Our recommendations for preparation of the site for use of shallow foundation systems are presented
below. This approach to improving and maintaining site soils has been found to be successful on
projects having similar soil conditions.
Lot A-3 Residence Geotechnical Exploration Report
10751 S Ocean Boulevard, Jensen Beach, Florida March 16, 2020
GFA Project No.: 20-8566.00 Page 4 of 6
1. Initial site preparation should consist of removing surface vegetation, topsoil, near surface roots,
and other miscellaneous debris within and to a distance of 5 feet beyond of the planned construction
limits. Foundations and the below grade remain of former structures within the footprint of the new
construction should also be removed. Similarly, utility lines within the limits of the proposed
construction should be removed or properly abandoned so that they will not adversely impact
overlying structures.
2. Following site stripping and prior to the placement of fill, areas of surficial sand should be compacted
(proof rolled) and tested. We recommend using a steel drum vibratory roller with sufficient static
weight and vibratory impact energy to achieve the required compaction. Density tests should be
performed on the proof rolled 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.
3. Fill material may then be placed for the building pad and general site grading, as required. The fill
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
materials having silt/clay-size soil fines contents exceeding 12 percent. Fill should be placed
in lifts having a maximum thickness of 12-inches. Each lift should be compacted and tested prior to
the placement of the next lift. Density tests should be performed within the fill at a frequency of not
less than one test per 2,500 square feet per lift in building areas, or a minimum of three (3) tests
per lift, whichever is greater.
4. For foundations placed on structural fill or compacted native granular soils, the bearing subgrade
should be tested for compaction and observed by an engineer or geologist or his/her representative
to determine if the soil is free of organic and/or deleterious material. Density tests should be
performed at a frequency of not less than one (1) density test per each isolated column footing and
one (1) test per each seventy-five (75) lineal feet of wall footing.
5. The contractor should consider the final grading contours contained in the project plans when
executing backfilling and compaction operations.
3.3 Vibration Monitoring
Using vibratory compaction equipment at this site may disturb nearby structures. Therefore, we
recommend that these structures be monitored by GFA both before and during compaction operations.
A proposal for providing vibration monitoring services during earthwork construction will be provided
upon request.
3.4 Design of Footings
A foundation system for any structure must be designed to resist bearing capacity failures, have
settlements that are tolerable, and resist the environmental forces that the foundation may be subjected
to over the life of the structure. The soil bearing capacity is the soil’s ability to support loads without
plunging into the soil profile. Bearing capacity failures are analogous to shear failures in structural
design and are usually sudden and catastrophic.
Lot A-3 Residence Geotechnical Exploration Report
10751 S Ocean Boulevard, Jensen Beach, Florida March 16, 2020
GFA Project No.: 20-8566.00 Page 5 of 6
Based on the results of the soil borings performed at the site, GFA recommends the structure
foundations be designed using a maximum allowable soil bearing pressure of 2,500 psf. Shallow
foundations should be embedded a minimum of 12 inches below final grade measured from the lowest
adjacent grade. Isolated column footings should be at least 24 inches in width. Continuous strip
footings should have a width of at least 16 inches regardless of contact pressure.
Once site preparation has been performed in accordance with the recommendations presented in this
report, the soils should readily support the proposed structure bearing upon a properly designed and
constructed shallow foundation system. Footings and columns should be structurally separated from
the ground floor slab, as they will be loaded differently and at different times, unless a monolithic slab
foundation is designed.
3.5 Settlement Estimates
Post construction settlements of the structure will be influenced by several interrelated factors, including
(1) subsurface soil stratification and the strength/compressibility characteristics, (2) footing size,
bearing level, applied loads, and resulting bearing pressure beneath the footings, and (3) the site
preparation and earthwork construction techniques used by the contractor. Our settlement estimates
for the proposed construction are based on the use of the site preparation and earthwork construction
methods as recommended in this report. Any deviation from these recommendations could result in
an increase in the estimated post-construction settlements of the proposed construction.
We expect the majority of settlement to occur in an elastic manner and fairly rapidly during construction.
Using the recommended maximum bearing pressure, the assumed maximum structural loads, and the
field test data that we have correlated geotechnical strength and compressibility characteristics of the
subsurface soils, we estimate that total settlements of the structure could be on the order of one (1)
inch or less.
Differential settlements result from differences in applied bearing pressures and variations in the
compressibility characteristics of the subsurface soils. Because of the general uniformity of the
subsurface conditions and the recommended site preparation and earthwork construction methods
presented in this report, we anticipate that differential settlements of the structure should be within
tolerable magnitudes (0.5 inch or less).
3.6 Ground Floor Slabs
Ground floor slabs may be constructed upon either existing grade or granular fill following completion
of the foundation site preparation and fill placement procedures outlined in this report. We recommend
that a modulus of subgrade reaction (k) of 150 pounds per cubic inch (pci) be considered during design.
The floor slabs should be structurally separated from walls and columns to allow for differential vertical
movement, unless monolithic slab foundations are designed.
Excessive moisture vapor transmission through foundation slabs can result in damage to floor
coverings as well as cause other deleterious affects. An appropriate moisture vapor barrier should be
placed beneath the slab to reduce moisture vapor from entering the structure through the slab. The
barrier should be installed in general accordance with applicable ASTM procedures including sealing
around pipe penetrations and at the foundation edges.
Lot A-3 Residence Geotechnical Exploration Report
10751 S Ocean Boulevard, Jensen Beach, Florida March 16, 2020
GFA Project No.: 20-8566.00 Page 6 of 6
4.0 REPORT LIMITATIONS
This consulting report has been prepared for the exclusive use of JWN Builders, LLC and the project
design team for the proposed residence located at 10751 S Ocean Drive (Lot A-3) in Jensen Beach,
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 information and
professional opinions provided in this report. In the event changes are made in the nature, design, or
location of the proposed structure, 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 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.
5.0 BASIS FOR RECOMMENDATIONS
The analysis and recommendations submitted in this report are based on the data obtained from the
tests performed at the locations indicated on the Test Location Plan in Appendix B. This report does
not reflect any variations which may occur between borings. While the borings are representative of
the subsurface conditions at their respective locations and for their vertical reaches, local variations
characteristic of the subsurface soils of 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 our geotechnical report or parts thereof is strictly prohibited without the
expressed written consent of GFA International, Inc. The applicable SPT methodology (ASTM D 1586)
and auger boring methodology (ASTM D 1452) 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
Lot A-3 Residence
10751 S Ocean Drive, Jensen Beach, Florida
PROJECT NO: 20-8566.00 DRAFTED BY: JR REVIEWED BY: JK DATE: 3/12/2020
N
Site Location
Appendix B - Test Location Plan
Test Location Plan
Lot A-3 Residence
10751 S Ocean Drive, Jensen Beach, Florida
PROJECT NO: 20-8566.00 DRAFTED BY: JR REVIEWED BY: JK DATE: 3/12/2020
N
B-1
B-2
Legend
Approximate 15’ Standard Penetration Test Boring Locations
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
20
40
80
80
3
2
2
1
1
2
4
4
4
7
10
13
7
7
4
Brown fine sand, trace roots (SP)
Gray fine sand (SP)
Brown fine sand, trace silt (SP)
Gray fine sand, trace shell fragments (SP)
Light brown fine sand, some shell (SP)
Bottom of borehole at 15.0 feet.
2.0
5.0
6.0
13.5
15.0
1
2
3
4
5
6
4
6
17
11
HAMMER TYPE
HOLE DIAMETER 3 in
DRILLER PM/JB
DRILL RIG GeoProbe
METHOD SPT
HOLE DEPTH 15 ft
DATE STARTED 3/2/20 COMPLETED 3/2/20
AT TIME OF DRILLING 4.10 ft
NOTE:
GROUND WATER LEVEL:
DRILLING CONTRACTOR GFA International Inc.
LATITUDE LONGITUDE
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PROJECT NUMBER 20-8566.00
PROJECT NAME Lot A-3 Residence
PROJECT LOCATION 10751 S Ocean Drive, Jensen Beach, Florida
LOG OF BORING B-1
PAGE 1 OF 1
CLIENT JWN Builders, LLC
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GFA International, Inc.
607 NW Commodity Cove
Port Saint Lucie, Florida 34986
(772) 924-3575
20
80
80
80
3
2
2
4
3
6
8
10
5
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32
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7
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Brown fine sand, trace shell fragments, trace roots (SP)
Dark gray fine sand, trace shell fragments (SP)
Gray fine sand, trace rocks, trace organics (SP)
Brown-gray fine to medium sand, trace shell fragments (SP)
Gray fine to medium sand, trace shell fragments (SP)
Bottom of borehole at 15.0 feet.
3.5
5.0
6.0
13.5
15.0
1
2
3
4
5
6
4
14
43
23
HAMMER TYPE
HOLE DIAMETER 3 in
DRILLER PM/JB
DRILL RIG GeoProbe
METHOD SPT
HOLE DEPTH 15 ft
DATE STARTED 3/2/20 COMPLETED 3/2/20
AT TIME OF DRILLING 4.10 ft
NOTE:
GROUND WATER LEVEL:
DRILLING CONTRACTOR GFA International Inc.
LATITUDE LONGITUDE
SA
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MATERIAL DESCRIPTION
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PROJECT NUMBER 20-8566.00
PROJECT NAME Lot A-3 Residence
PROJECT LOCATION 10751 S Ocean Drive, Jensen Beach, Florida
LOG OF BORING B-2
PAGE 1 OF 1
CLIENT JWN Builders, LLC
DE
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7.5
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GFA 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.