HomeMy WebLinkAboutReport of Supplemental Geotechnical ExplorationGFA INTERNATIONAL
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Report of Supplemental Geotechnical Exploration
Riazzi Residence
12 Nettles Boulevard
Jensen Beach, Florida
May 20, 2020
GFA Project No. 20-9023.00
For: Richard Riazzi
Florida's Leading Engineering Source
Environmental • Geotechnical • Construction Materials Testing • Threshold and Special Inspections • Plan Review & Code Compliance
May 20, 2020
Mr. Richard Riazzi
1207 Nettles Boulevard
Jensen Beach, Florida 34957
Subject: Report of Supplemental Geotechnical Exploration
Riazzi Residence
12 Nettles Boulevard, Jensen Beach, Florida
GFA Project No. 20-9023.00
Dear Mr. Riazzi:
GFA International, Inc. (GFA) has completed the supplemental subsurface exploration and
geotechnical engineering evaluation for the above referenced project in accordance with the
geotechnical and engineering service agreement for this project. Our scope of services was
completed in accordance with our Change Order No. 1 dated May 6, 2020, planned in
conjunction with and authorized by you.
GFA performed a geotechnical exploration at the referenced property in March 2020. The
results were presented in our Report of Geotechnical Exploration dated March 25, 2020. GFA
later learned that an augered cast -in -place (ACIP) pile foundation system is required for the
proposed residence due to its proximity to the seawall on Nettles Island. The supplemental field
exploration performed for this study included one (1) 40-feet deep boring to provide information
required to develop geotechnical recommendations for the design and installation of the ACIP
piles.
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 recent telephone discussions and email correspondence with Mr. James Newman of
JWN Builders LLC and you, we understand that you plan to construct a new 2-story residence
at the subject property on Nettles Island. No house plans are currently available. As previously
noted, the residence will be supported by deep foundations consisting of ACIP piles.
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.
607 NW Commodity Cove • Port St Lucie, Florida 34986 • (772) 924.3575 • (772) 924.3580
Riazzi Residence Supplemental Geotechnical Exploration Report
12 Nettles Boulevard, Jensen Beach, Florida May 20, 2020
GFA Project No. 20-9023.00 Page 2 of 10
One (1) standardpenetration test (SPT) boring (13-3), advanced to an approximate depth of 40
feet below the existing ground surface, was completed for this study. Two (2) standard
penetration test (SPT) borings (B-1 and B-2), advanced to depths of approximately of 15 feet
below the existing ground surface, were performed for our initial geotechnical exploration.
The subsurface soil conditions encountered at the boring locations generally consisted of very
loose to medium dense fine sand (SP) and fine sand with silt (SP-SM) to the boring termination
depths. As an exception, a layer of loose clayey fine sand was present in boring B-3 between
approximate depths of 3 and 5 feet below the existing ground surface.
Axial compressive and tension capacities for both 14-inch and 16-inch diameter ACIP piles were
developed for the project. The results of our analysis are contained in the table in Section 3.2 of
this report.' Note that the pile installation lengths in the tables are relative to the current ground
surface at the boring locations. The piles will be longer or shorter based on depth of fill added
or elevation adjustments.
If the ground level floor slab will not be designed as a structural slab supported by the ACIP pile
foundations, the upper two (2) feet of the loose fine sand soils encountered in the borings will
require densification below the proposed structure during initial site preparation to reduce the
risk for the occurrence of excessive floor slab settlements and associated structural distress.
These soils should be compacted until achieving a minimum of 95 percent of modified Proctor
(ASTM D 1557) maximum dry density prior to placing any fill that may be required to achieve
final grade. Fill should be placed in maximum 12-inch thick lifts and compacted to achieve the
same criteria stated above.
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
John Digitally signed
by John Kent
Kent J- Date:, 2020.05.20
15:09.37-04'00'
John Kent, P.E.
Senior Project Engineer
Florida Registration No. 63218
Distribution: Mr. Richard Riazzi
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.
Erik Soderstrom, E.I.
Geotechnical Department Manager
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Riazzi Residence Supplemental Geotechnical Exploration Report
12 Nettles Boulevard, Jensen Beach, Florida May 20, 2020
GFA Project No. 20-9023.00 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.............................................................................................................
4
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.............................................................................................
7
3.4
Ground Supported Floor Slabs........................................................................................
8
3.5
Site Preparation..............................................................................................................
8
3.6
Fill Placement and Compaction.......................................................................................
9
3.7
Quality Control and Vibration Monitoring.........................................................................
9
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
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Riazzi Residence Supplemental Geotechnical Exploration Report
12 Nettles Boulevard, Jensen Beach, Florida May 20, 2020
GFA Project No. 20-9023.00 Page 4 of 10
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 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 ACIP pile
foundation support for the proposed 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 recent telephone discussions and email correspondence with Mr. James Newman of
JWN Builders LLC and you, we understand that you plan to construct a new 2-story residence
at the subject property on Nettles Island. No house plans are currently available. As previously
noted, the residence will be supported by deep foundations consisting of ACIP piles.
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 explorations, the site was generally flat and contained a modular home
and concrete pavement. Similar residential properties and the Jensen Beach to Jupiter Inlet
Aquatic Preserve were located adjacent to the site.
2.2 Field Exploration
One (1) standard penetration test (SPT) boring (B-3), advanced to an approximate depth of 40
feet below the existing ground surface, was completed for this study. Two (2) standard
penetration test (SPT) borings (B-1 and B-2), advanced to depths of approximately of 15 feet
below the existing ground surface, were performed for our initial geotechnical exploration. The
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Riazzi Residence Supplemental Geotechnical Exploration Report
12 Nettles Boulevard, Jensen Beach, Florida May 20, 2020
GFA Project No. 20-9023.00 Page 5 of 10
boring depths were based upon our knowledge of vicinity soils and confined to the zone of soil
likely to be influenced by the proposed 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.
The upper 4 feet of the borings were advanced by hand augering due to potential buried utility
line conflicts. The augered portions of the 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 and
estimated distances and relationships to existing landmarks at the site.
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 Arents, 0 to 5
percent slopes (100). 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. 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 on the logs are generally based upon visual characterizations of
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Riazzi Residence Supplemental Geotechnical Exploration Report
12 Nettles Boulevard, Jensen Beach, Florida May 20, 2020
GFA Project No. 20-9023.00 Page 6 of 10
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 very
loose to medium dense fine sand (SP) and fine sand with silt (SP-SM) to the boring termination
depths. As an exception, a layer of loose clayey fine sand was present in boring B-3 between
approximate depths of 3 and 5 feet below the existing ground surface.
2.6 Hydrogeological Conditions
On the dates of our field exploration (March 18 and May 15, 2020), groundwater was
encountered at an approximate depth of 5 feet below the ground surface of 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 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
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 utilizing a factor of
safety of 2.0.
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Riazzi Residence Supplemental Geotechnical Exploration Report
12 Nettles Boulevard, Jensen Beach, Florida May 20, 2020
GFA Project No. 20-9023.00 Page 7 of 10
Table 3.2.1 — ACIP Pile Design Recommendations
Nominal Pile
Diameter in
Pile Top
Elevation
Recommended
Pile Tip
Elevation
Pile
Length
ft
Maximum Allowable
Pile Compression
Capacity
Pile Allowable
Tension
Capacity
Grout
Strength
(psi)
14
Unknown
Unknown
32
42 kips
14 kips
5,000
16
Unknown
Unknown
32
55 kips
16 kips
5,000
The pile depths in the 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.
The following notes are also applicable to the ACIP pile design:
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.
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:
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.
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Riazzi Residence Supplemental Geotechnical Exploration Report
12 Nettles Boulevard, Jensen Beach, Florida May 20, 2020
GFA Project No. 20-9023.00 Page 8 of 10
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 Ground Supported Floor Slabs
Ground supported (on -grade) slabs may be constructed upon either existing grade or granular
fill following completion of the foundation site preparation and fill placement procedures outlined
in Sections 3.5 and 3.6 of this report. We recommend that a modulus of subgrade reaction (k)
of 150 pounds per cubic inch (pci) be considered during design. The floor slab should be
structurally separated from pile caps and grade beams to allow for differential vertical
movement.
Excessive moisture vapor transmission through on -grade 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.
3.6 Site Preparation
Initial site preparation should consist of removing all surface vegetation, near surface roots,
pavement, 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.
If the ground level floor slab will not be designed as a structural slab supported by the ACIP pile
foundations, the subgrade soils should be improved (densified) with compaction from the
stripped grade prior to constructing the slab. The upper two (2) feet of the loose fine sand soils
encountered in the borings will require densification below the proposed structure during initial
site preparation to reduce the risk for the occurrence of excessive floor slab settlements and
associated structural distress. The soils should be compacted in accordance with the criteria
discussed in Section 3.6 below.
CFP
Riazzi Residence
12 Nettles Boulevard, Jensen Beach, Florida
GFA Project No. 20-9023.00
3.6 Fill Placement and Compaction
Supplemental Geotechnical Exploration Report
May 20, 2020
Page 9 of 10
Fill should be inorganic (i.e., contain less than 5 percent by weight organic material) and have a
USCS classification of 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.
The upper two (2) feet of soils below ground supported slabs and all fill required for the project
should be compacted until achieving 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. Note that it may be necessary to operate
the roller in the static mode due to the proximity of the adjacent lots. In general, fill should
be placed in maximum 12-inch thick loose lifts. Each lift of fill should be compacted and tested
prior to the placement of the next lift.
Density tests should be performed at a frequency of not less than one test per 2,500 square feet
per lift, 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.
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.
3.7 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 afford 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 proposed construction will be close to nearby residential structures and roadways that
could be susceptible to damage from vibrations generated at the site during site preparation and
foundation installation. We recommend 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.
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Riazzi Residence Supplemental Geotechnical Exploration Report
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GFA Project No. 20-9023.00 Page 10 of 10
4.0 REPORT LIMITATIONS
This consulting report has been prepared for the exclusive use of Mr. Richard Riazzi and the
project design team for the proposed residence located at 12 Nettles Boulevard 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 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.
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
extents, 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 dates 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.
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Appendix A - Vicinity Map
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Site Location
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Appendix B - Test Location Plan
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Test Location Plan
PROJECT NO: 20-9023.00
Legend
Riazzi Residence
12 Nettles Boulevard, Jensen Beach, Florida
DRAFTED BY: JR REVIEWED BY: JK DATE: W19/2020
m Approximate 15' Standard Penetration Test Boring Locations
® Approximate 40' Standard Penetration Test Boring Location
N
Appendix C - Notes Related to Borings
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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/cm�
CPT Value
(tsf)
Relative
Density
SPT
N-Value
HCP Value
(kg/cmz)
CPT Value
(tsf)
Consistent y
0-4
0- 6
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 areas follows:
Description
Particle Size Limits
Boulder
Greater than 12 inches
Cobble
3 to 12 inches
Coarse Gravel
314 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/Cla
Smaller than No. 200 sieve
11. Definitions for modifiers used in soil/rock descriptions:
Proportion
Modifier
Approximate Root Diameter
Modifier
<5%
Trace
Less than /3z'
Fine roots
5% to 12%
Little
1/3z" to'/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
GFA
Appendix D - Log of Boring Records
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9
International, LOG OF BORING B-
6GFA 07N 1
NW Commodity Cove
Port
Port Saint Lucie, Florida 34986 PAGE 1 OF 1
(772) 924-3575
NAT�� P
CLIENT Richard Riazzi PROJECT NAME Riazzi Residence
PROJECT NUMBER 20-9023.00 PROJECT LOCATION 12 Nettles Boulevard, Jensen Beach, Florida
DRILLING CONTRACTOR GFA International Inc. HOLE DEPTH 15 ft HOLE DIAMETER 3 in
DRILLER PM/CM/EN DATE STARTED 3/18/20 COMPLETED 3/18/20
DRILL RIG CME-45 GROUND WATER LEVEL: -VAT TIME OF DRILLING 5.00 ft
METHOD SPT LATITUDE LONGITUDE
NOTE: HAMMER TYPE
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2.5
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30
40
5.
X3
2
4
6
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5
5.5
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3
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4
2
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4
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2
3
t
10.
12.
:.'
13.5
Gray fine sand with silt, trace shell (SP-SM)
5
6
a
7
15.0
Bottom of borehole at 15.0 feet.
International, LOG OF BORING B-2
6GFA 07N
NW Commodity Cove
Port Saint Lucie, Florida 34986 PAGE 1 OF 1
Port
(772) 924-3575
4� P
•`�1NAT4�
CLIENT Richard Riazzi PROJECT NAME Riazzi Residence
PROJECT NUMBER 20-9023.00 PROJECT LOCATION 12 Nettles Boulevard, Jensen Beach, Florida
DRILLING CONTRACTOR GFA International Inc. HOLE DEPTH 15 ft HOLE DIAMETER 3 in
DRILLER PM/CMIEN DATE STARTED 3118/20 COMPLETED 3118/20
DRILL RIG CME-45 GROUND WATER LEVEL: 9AT TIME OF DRILLING 5.00 ft
METHOD SPT LATITUDE LONGITUDE
NOTE: HAMMER TYPE
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faird
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Asphalt (2")
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1
so
2.5
2
60
60
5.
SZ
3
2
4
6
12
2
-X
4
1
6
7
7.5
8.0
Gray fine sand with silt (SP-SM)
2
5
3
5
8
2
10.
12.
6
e
9
15.0
Tv Bottom of borehole at 15.0 feet.
International, Inc. LOG OF BORING B-3
NW Commodity Cove
6F�GFA
or
Port
PSaint Lucie, Florida 34986 PAGE 1 OF 2
(772) 924-3575
CLIENT Richard Riazzi PROJECT NAME Riazzi Residence
PROJECT NUMBER 20-9023.00 PROJECT LOCATION 12 Nettles Boulevard, Jensen Beach, Florida
DRILLING CONTRACTOR GFA International Inc. HOLE DEPTH 40 ft HOLE DIAMETER 3 in
DRILLER PM/SK/CM DATE STARTED 5/15/20 COMPLETED 5/15/20
DRILL RIG Simco GROUND WATER LEVEL: -7--AT TIME OF DRILLING 5.00 ft
METHOD SPT LATITUDE LONGITUDE
NOTE: HAMMER TYPE
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MATERIAL DESCRIPTION
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0.8
Gray fine sand, trace shell (SP)
1
eo
80
2
30
:
3.0
Dark gray clayey fine sand (SC)
40
5
3
2
2
5.0
Dark gray fine sand With silt, trace shell (SP-SM)
s
5
6
4
6
7.0
Gray fine sand (SP)
10
15
5
7
::
9.0
Gray fine sand, trace silt (SP)
7
16
io-x8
7
6
3
6
15
:.'
18.5
Gray fine sand, trace shell (SP)
6
7
7
14
`" (Continued Next Page)
International, Inc. LOG OF BORING B-3
607
607 NW Commodity Cove
Port Saint Lucie, Florida 34986 PAGE 2 OF 2
(772) 924-3575
CLIENT Richard Ri=i PROJECT NAME Riazzi Residence
PROJECT NUMBER 20-9023.00 PROJECT LOCATION 12 Nettles Boulevard, Jensen Beach, Florida
LLl
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MATERIAL DESCRIPTION
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Gray fine sand, trace shell (SP) (continued)
5
8
3
9
25
s
9
10
18
'
30
33.5
Brown fine sand, trace shell and cemented sand (SP)
ze
10
12
20
35
38.5
Gray fine sand, little silt (SP)
E
11
i
12
40.0
Bottom of borehole at 40.0 feet.
Appendix E - Discussion of Soil Groups
601
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.
6FP
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.
6rp