HomeMy WebLinkAboutREPORT OF GEOTECHNICAL EXPLORATIONL
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GI=A INTERNOATIONAL
FLORIDA'SLEADING ENGINEERING SOURCE
Report oGeotechnical Exploration
Proposed Two -Story Residence
% Development Lot 5
4434 i:. t ,1St. LucieCounty, Florida
June h
GFA Project No.: 15-0786.00
For: AJT ConstructionConsulting,
l " Florida's Leading Engineering Source
Environmental -Geotechnical - Construction Materials Testing -'threshold and Special Inspections • Plan Review & Code Compliance
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June 26, 2015
AJT Construction Consulting, LLC
Attention: Mr. Alan Tarpell
1760 N. Jog Road, Suite 140
West Palm Beach, Florida 33411
Site: Proposed Two -Story Residence
Aquavista Development BLK A Lot 5
4434 A1A, St. Lucie County, Florida
GFA Project # 15-0786.00
Dear Mr. Tarpell:
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 (15-0986.00) dated May 7, 2015,
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 and evaluate their impact upon the proposed construction. This
report contains the results of our subsurface exploration at the site and our engineering
interpretations of these, with respect to the project characteristics described to us including
providing recommendations for site preparation and the design of the foundation system.
Based on conversations with the client, the project consists of constructing a two-story
residence. The residential structure (or portion thereof) will be located east of the Coastal
Construction Control Line (CCCL) and therefore a pile supported foundation is required. GFA
was informed that the residence will be elevated above a lower level garage that will have walls
and ground floor slab of frangible breakaway design.
The recommendations provided herein are based upon the above considerations. If the project
description has been revised, please inform GFA International so that we may review our
recommendations with respect to any modifications.
A total of one (1) standard penetration test (SPT) boring to a depth of approximately forty (40)
feet, and one (1) Cone Penetrometer Test (CPT) sounding to a depth of approximately twenty-
five (25) feet terminated due to refusal on very dense/hard soil, below ground surface (BGS)
were completed for this study. Additional borings and soundings were performed on the
adjacent lots and the information is used to supplement this report.
521 OW Enterprise Drive ® Port St. Lucie, Florida 34986 4 (772) 924.3575 • (772) 924.3580
OFFICES THROUGHOUT FLORIDA
Proposed Two -Story Residence Geotechnical Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26,, 2016
GFA Project No. 15-0786.00 Page of 12
The subsurface soil conditions encountered at this site (with information from borings performed
from adjacent lots), generally consist of loose to medium sand (SP) to 4 feet, medium dense
sand (SP) from 4 to 23% feet, and then medium dense to very dense sand (SP) with cemented
sand seams and layers the boring termination depths. Please refer to Appendix D - Record of
Test Borings for a detailed account of each boring and sounding.
GFA recommends that the proposed residence be supported using a deep foundation system
consisting of augered cast -in -place (ACIP) piles. Based on our analysis, GFA has estimated
that a 14 or 16-inch-diameter ACIP pile installed to a depth of 30 feet below grade existing
grade can provide a maximum allowable axial compressive capacity of 40 tons and a maximum
tension capacity of 12 tons.
For the ground supported frangible walls, an allowable bearing capacity of 2,500 psf may be
used for shallow footing foundation design.
The subgrade soils should be improved with compaction from the stripped grade prior to
constructing the foundation pads and footing excavations. The top 2 feet below stripped grade
should be compacted to a minimum of 95% density prior to placing fill to achieve final grade.
Fill (including stemwall backfill) should be placed in 12-inch lifts and compacted to achieve a
minimum 95% density. After excavation for footings, the subgrade to a depth_of 2 feet below
bottom of footings should be compacted to achieve a minimum 95% density.
Scour elevations used in pile calculations are those provided by the Florida DEP for coastal
construction, but may not be adequate for actual scour elevations in hurricane(s) event(s) that
exceed the DEP assumptions and cause lower scour elevations. Therefore, GFA analysis is
limited to that provided by the DEP scour elevation, and scour analysis is not included in our
scope of work.
We appreciate the opportunity to be of service to you on this 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.
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Proposed Two -Story Residence Geotechnicai Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 3 of 12
E _ �
1.0 INTRODUCTION.................................................................................................................4
1.1
Scope of Services............................................................................................................4
1.2
Project Description...........................................................................................................4
2.0 OBSERVATIONS
..........................................................................................................:......5
2.1
Site Inspection.................................................................................................................5
2.2
Field Exploration....................................................................................................I..........5
2.3
Laboratory Analysis..........................................................................................................5
2.4
Geomorphic Conditions....................................................................................................6
2.5
Hydrogeological Conditions..............................................................................................6
3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS..............................................7
3.1
Foundation Recommendations - General.........................................................................7
3.2
Pile Foundation................................................................................................................7
3.3
Pile Installation.................................................................................................................8
3.4
Vibration Monitoring.........................................................................................................9
3.5
Design of Footings (Ground Level Frangible Walls).........................................................9
3.6
Ground Floor Slab (Frangible)..........................................................................................9
3.7
Site Preparation...............................................................................................................9
4.0 REPORT LIMITATIONS .....................................................................................................11
5.0 BASIS FOR RECOMMENDATIONS ........
Appendix A - Vicinity Map
Appendix B - Test Location Plan
Appendix C - Notes Related to Borings
Appendix D - Record of Test Borings
Appendix E - Discussion of Soil Groups
u
......................................................1.1
Proposed Two -Story Residence Geotechnical Report
Aquavista Lot 5 (4434 AM), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 4 of 12
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 are provided
within this report-
1 . Prepare records of the soil boring logs depicting the subsurface soil conditions encountered
during our field exploration.
2. Conduct a review of each soil sample obtained during our field exploration for classification
and additional testing if necessary.
3. Analyze 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
allowable soil -bearing capacity, bearing elevations, and foundation design parameters.
5. Provide criteria and site preparation procedures to prepare the site for the proposed
construction.
1.2 Project Description
Based on conversations with the client, the project consists of constructing a two-story
residence. The residential structure (or portion thereof) will be located east of the Coastal
Construction Control Line (CCCL) and therefore a pile supported foundation is required. GFA
was informed that the residence will be elevated above a lower level garage that will have walls
and ground floor slab of frangible breakaway design.
Based on a site visit and elevations from topographic data from GoogleEarth website, the
current grade at the location of the proposed residence varies from about +8 on the west side
and slopes upwards to the east to +11 feet NGVD. Assuming the proposed house will have a
ground level garage grade about +9 feet NGVD, about 0 to 2 feet of fill will be required to
achieve final grade.
We assume the residence will have typical construction, and be supported on columns
terminating on pile caps slightly below the ground floor elevation. We assume that fill will be
placed to achieve final (or near final) grade before installing the pile foundations, and top of piles
(bottom of pile caps) would be about +8 feet NGVD.
We have not received any information regarding structural loads. For the foundation
recommendations presented in this report we assumed the maximum column load will be 80
kips and the maximum wall loading will be 4 kips per linear foot.
Proposed Two -Story Residence Geotechnicai Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 5 of 12
The recommendations provided herein are based upon the above considerations. If the project
description has been revised, please inform GFA International so that we may review our
recommendations with respect to any modifications.
2.1 Site Inspection
The project site was generally grassy with some palm trees and bushes. The site was about
even with the adjacent road on the west side and sloped upwards to the east, and at the end of
the east side of the lot the grade varied with dunes and vegetation. The Atlantic Ocean bordered
the east side of the property on the east side of the dunes.
2.2 Field Exploration
A total of one (1) standard penetration test (SPT) boring to a depth of approximately forty (40)
feet, and one (1) Cone Penetrometer Test (CPT) sounding to a depth of approximately twenty-
five (25) feet terminated due to refusal on very dense/hard soil, below ground surface (BGS)
were completed for this study. Additional borings and soundings were performed on the
adjacent lots and the information is used to supplement this report. The locations of the borings
and soundings performed are illustrated in Appendix B: "Test Location Plan". The Standard
Penetration Test (SPT) and Cone Penetrometer Test (CPT) methods were used as the
investigative tools within the borings. SPT tests were performed in substantial accordance with
ASTM Procedure D-1586, "Penetration Test and Split -Barrel Sampling of Soils" and the Cone
Penetrometer Test (CPT) in substantial accordance with ASTM Procedure D-3441, "Deep
Quasi -Static, Cone and Friction Cone Penetration Tests of Soils". The SPT test procedure
consists of driving a 1.4-inch I.D. split -tube sampler into the soil profile using a 140-pound
hammer failing 30 inches. The number of blows per foot, for the second and third 6-inch
increment, is an indication of soil strength.
The soil samples recovered from the soil borings were visually classified and their stratification
is illustrated in Appendix D: "Record of Test Borings". It should be noted that soil conditions
might vary between the strata interfaces, which are shown. The soil boring data reflect
information from a specific test location only. Site specific survey staking for the test locations
was not provided for our field exploration. The indicated depth and location of each test was
approximated based upon existing grade and estimated distances and relationships to obvious
landmarks. The boring and sounding depths were confined to the zone of soil likely to be
stressed by the proposed construction and knowledge of vicinity soils.
2.3 Laboratory Analysis
Soil samples recovered from our field exploration were returned to our laboratory where they
were visually examined in general accordance with ASTM D-2488. Samples were evaluated to
obtain an accurate understanding of the soil properties and site geomorphic conditions. After a
thorough visual examination of the recovered site soils, no laboratory testing was deemed
necessary. Bag samples of the soil encountered during our field exploration will be held in our
Proposed Two -Story Residence Geotechnical Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 6 of 12
laboratory for your inspection for 30 days and then discarded unless we are notified otherwise in
writing.
The recovered samples were not examined, either visually or analytically, for chemical
composition or environmental hazards. GFA would be pleased to perform these services for an
additional fee, if required.
12.4 Geomorphic Conditions
The geology of the site as mapped on the USDA Soil Survey website consists ofPalm Beach
fine sand, 0 to 5 percent slopes (27). These are sandy soils and organic soils are not
indicated. It should be noted that the Soil Survey generally extends to a maximum depth of 80
inches (approximately 63/ feet) below ground surface and is not indicative of deeper soil
conditions.
Boring logs derived from our field exploration are presented in Appendix D: 'Record of Test
Borings". The boring logs depict the observed soils in graphic detail. The Standard Penetration
Test borings indicate the penetration resistance, or N-values, and the CPT soundings the
penetration resistance values, logged during the testing and sampling activities. The
classifications and descriptions shown on the logs are generally based upon visual
characterizations of the recovered soil samples. All soil samples reviewed have been depicted
and classified in general accordance with the Unified Soil Classification System, modified as
necessary to describe typical Florida conditions. See Appendix E: "Discussion of Soil Groups",
for a detailed description of various soil groups.
The subsurface soil conditions encountered at this site (with information from borings performed
from adjacent lots), generally consist of loose to medium sand (SP) to 4 feet, medium dense
sand (SP) from 4 to 23'/z feet, and then medium dense to very dense sand (SP) with cemented
sand seams and layers the boring termination depths. Please refer to Appendix D - Record of
Test Borings for a detailed account of each boring and sounding.
2.5 Hydrogeological Conditions
On the dates of our field exploration, the groundwater table was encountered at a depth of
approximately 8 feet below the existing ground surface. The groundwater table will fluctuate
seasonally depending upon local rainfall and other site specific and/or local influences including
the water level in the nearby Atlantic Ocean with tidal influences. Brief ponding of stormwater
may occur across the site after heavy rains.
No additional investigation 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.
Proposed Two -Story Residence Geotechnical Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 7 of 12
3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS
3.1 Foundation Recommendations -General
The residential structure will be located east of the Coastal Construction Control Line (CCCL)
and therefore a pile supported foundation is required. Frangible ground floor slabs and ground
level walls may be pile supported or supported on footings in accordance with rules and
regulations (to be determined by others).
3.2 Pile Foundation
The following is design parameters GFA used for pile recommendations:
> 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 (depends on location) for
structures within St. Lucie County.
> For CCCL construction, the FDEP has established a 100-year storm erosion elevation
(design scour elevation) of +2.7 feet NGVD for all of St. Lucie County.
> A loss of soil support between the bottom of lowest structural member and design scour
elevation (+2.7 feet NGVD) was included in compressive, tensile, and lateral pile
capacity analyses.
> We assume the residence will have typical construction, and be supported on columns
terminating on pile caps slightly below the ground floor elevation. We assume that fill will
be placed to achieve final (or near final) grade before installing the pile foundations, and
top of piles (bottom of pile caps) would be about +8 feet NGVD.
At this time, GFA recommends the deep foundation to consist of augered cast -in -place piles
(ACIP). Additional lateral capacity may be attained by utilizing inclined piles. We assumed that
the piles will have a minimum of 1% steel reinforcement for the analyses. ACIP pile installation
procedures should be performed in accordance with the guidelines presented in the latest
edition of the Deep Foundations Institute's Augered Cast -In -Place Pile Manual. The lateral
capacity and pile top deflection were calculated using the commercially available L-pile 4.0
software. A summary of pile capacities for a 14-inch diameter ACIP piles is presented in the
following table.
Pile Recommendations For All Pile Supported Structures
Maximum
Nominal
Pile Top
Recommended
Pile
Pile
Pile
Pile Lateral
Pile
Elevation
Pile Tip
Lengths
Compression
Tension
Capacity
Recommended
Diameter
(NGVD)-
Elevation
ft **
Capacity
Capacity
(Tons)"*
Grout Strength
0.5 Tons
(Free Head)
14" or' 1.25 Tons
16" Unknown Unknown 30 40 Tons 12 Tons Fixed Head 5000 PSJ
*Pile top elevation assumed at, or more than, +6 feet NGVD for analyses.
**From ground surface existing at time of drilling.
***For calculated pile top deflection of inches at top of pile elevation.
Proposed Two -Story Residence Geotechnical Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 8 of 12
GFA assumed that the piles will have a minimum of 1 % steel reinforcement for the analyses.
Augercast piles should be reinforced over their entire length for tension capacity. The
reinforcement shall be as designed by the Structural Engineer.
If piles of lesser or greater capacities than those mentioned in the table above are required,
GFA would be pleased to provide further recommendations upon request.
The following additional notes are applicable to the pile design:
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.
The pile reinforcement is sufficiently embedded in the pile cap so as to afford a
fixed end connection if,required.
3.3 Pile Installation
Pile design and installation shall be in accordance with the applicable sections of the Florida
Building Code and other applicable federal, state and local requirements. In addition, piles
should be installed in accordance with the following:
1. Pile Length: The proposed 1 4-inch-d ia meter 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 piling 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 piling
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 shall be placed at maximum spacing of 15 feet at
the lower portion of the pile and at 5 feet from the cage's top.
6. Adjacent Piles - A minimum time period 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
theoretical grout volume) should be 1.1.
1
Proposed Two -Story Residence Geotechnical Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 9 of 12
3.4 Vibration Monitoring
The proposed construction will be within close proximity to residential structures and roadways
that maybe susceptible to damage from vibration generated at the site. We recommend that
during all aspects of construction, the bordering landmarks be monitored using a seismograph
to determine the extent of vibration absorption that these features will be subject to. The
seismograph used to monitor at this 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
any damage.
3.5 Design of Footings (Ground level Frangible Walls)
Footings may be designed using an allowable soil bearing pressure of 2,500 psf. Shallow
foundations should be embedded a minimum of 12 inches below final grade. This embedment
shall be measured from the lowest adjacent grade. Isolated column footings should be at least
24 inches in width and 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 described
in this report, the soil should readily support the proposed structure resting on a shallow
foundation system. Settlements have been projected to be less than 1-inch total and %2-inch
differential. All footings and columns should be structurally separated from the floor slab, as
they will be loaded differently and at different times, unless a monolithic mat foundation is
designed.
3.6 Ground Floor Slab (Frangible)
The ground floor slabs may be supported directly on the existing grade or on granular fill
following the foundation site preparation and fill placement procedures outlined in this report.
For purposes of design, a coefficient of subgrade modulus 150 pounds per cubic inch may be
used., The ground floor slab should be structurally separated from all walls and columns to
allow for differential vertical movement.
Water vapor is likely to rise through the granular fill and condense beneath the base of the floor
slab. If moisture entry into the floor slab is not desirable, an impermeable membrane should be
installed at the slab bottom - subgrade interface.
3.7 Site Preparation
GFA recommends the following compaction requirements for this project:
➢ Proof Roll......................................................................95% of a Modified Proctor
> Building Pad Fill............................................................95% of a Modified Proctor
➢ Footings........................................................................95% of a Modified Proctor
The compaction percentages presented above are based upon the maximum dry density as
determined by a "modified proctor" test (ASTM D-1557). All density tests should be
performed to a depth of 2 feet below stripped surface and 2 feet below bottom of
Proposed Two -Story Residence Geotechnical Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 10 of 12
footings. All density tests should be performed using the nuclear method (ASTM D-2922), the
sand cone method (ASTM D-1556), or Hand Cone Penetrometer (HCP) tests.
Our recommendations for preparation of the site are presented below. This approach to
improving and maintaining the site soils has been found to be successful on projects with similar
soil conditions.
Initial site preparation should consist of performing stripping (removing surface vegetation,
near surface roots, and other deleterious matter) and clearing operations. This should be
done within, and to a distance of five (5) feet beyond, the perimeter of the proposed building
footprint (including exterior isolated columns). Foundations and any below grade remains of
any structures that are within the footprint of the new construction should be removed, and
utility lines should be removed or properly abandoned so as to not affect structures. If the
demolished residence had a pile foundation, GFA must be notified as the recommendations
may change.
2. Following site stripping and prior the placement of any fill, areas of surficial sand (not
exposed limestone) 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. Areas of exposed intact limestone shall be visually confirmed
by the project geotechnical engineer prior to fill placement, in lieu of proof rolling.
3. Fill material may then be placed in the building pad as required. The fill material should be
inorganic (classified as SP, SW, GP, GW, SP-SM, SW-SM, GW-GP, GP -GM) containing not
more than 5 percent (by weight) organic materials. Fill materials with slit/clay-size soil
fines in excess of 12% should not be used. Fill should be placed in lifts with a maximum
lift thickness not exceeding 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 the building areas, or a minimum of
three (3) tests per lift, whichever is greater.
4. For any footings bearing on a limestone formation, the bottom of all footing excavation shall
be examined by the engineer / geologist or his representative to determine the condition of
the limestone. The limestone shall be probed for voids and loose pockets of sand. Such
areas shall be cleaned to depth of 3 times the greatest horizontal dimension and backfilled
with lean concrete.
5. For footings placed on structural fill or compacted native granular soils, the bottom of all
footings shall be tested for compaction and examined by the engineer / geologist or his
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
footings.
Residence 8eo��n�/R�o
Proposed' I/U.3iLucie County, FL June 26,2OY8
O. Upon completion of production pile installation and pile cap oonatruoUon, the pile oopo
should be. backfiUed in8to8inch thick lifts and compacted to at leastQ5% of the modified
Proctor maximum dry density (ASTM D 1557).
7. The contractor should take into account the final contours and grades as established by the
plan when executing his baokfiUingand compaction operations.
Using vibratory compaction equipment at this site may disturb adjacent structures' We
recommend that you monitor before and during proof -compaction operations.
A representative of GFA International can monitor the vibration disturbance of adjacent
structures. /\ proposal for vibration monitoring during compaction operations can be supplied
upon request.
This consulting report has been prepared for the exclusive use of the current project owners and
other members ofthe design team for the Proposed Two -Story Residence located atAouavista
Lot5. 4434A1A. St. Lucie County, Florida. This report has been prepared in accordance with
generally accepted local geotechniva| engineering practices; no other warranty is expressed or
implied. The evaluation submitted in this report, is based in part upon the data collected during,
e field exp|oratiun, h¢vvever, the nature and extent of variations throughout the subsurface
profile may not become evident until the time ofconstruction. (fvariations then appear evident,
it may be necessary to naema|uaba information and professional opinions as provided in this
report. In the event changes are mode in the nature, design, or locations of the proposed
etructuue, the evaluation and opinions contained in this report shall not be considered *gUd,
unless the changes are reviewed and conclusions modified or verified in xxhbng by GFA
International.
Scour elevations used in pile calculations are those provided by the Florida DEPfor coastal
oonstnuotion, but may not be adequate for actual scour elevations in hurricane(s) event(s) that
exceed the DEP assumptions and cause lower scour elevations, Therefore, GFAmna|Vaio is
limited to that provided by the []Ep scour m|evobon, and scour analysis is not included in our
scope ofwork.
The anak�o��c�m��mu�U������a�����d�m�h�
�onmthe' tests performed at the locations indicated on the attached figure 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 [heir respective locations and for their vertical
reaches, local variations characteristic ofthe subsurface soils ofthe region are anticipated and
may boencountered. The delineation between soil types shown onthe soil logs is approximate
and the description represents our interpretation ofthe subsurface conditions o1the designated
boring locations onthe particular date drilled.
1
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Proposed Two -Story Residence Geotechnicai Report
Aquavista Lot 5 (4434 A1A), St. Lucie County, FL June 26, 2016
GFA Project No. 15-0786.00 Page 12 of 12
Any third party reliance of our geotechnical report or parts thereof is strictly prohibited without
the expressed written consent of GFA International. The applicable SPT methodology (ASTM
D-1586), CPT methodology (ASTM D-3441), and Auger Boring methodology (ASTM D-1452)
used' in performing our borings and sounding, and for determining penetration and cone
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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Proposed Two -Story Residence
4434 AlA, St. Lucie County, FL
GFA Project No. 15-0786.00
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Development
Plan
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NOTES RELATED TO
RECORDS OFrTEST BORING AND
GENERALIZED SUBSURFACE PROFILE
1. Groundwater level was encountered and recorded (if shown) following the completion of the soil test boring on
the date indicated. Fluctuations in groundwater levels are common; consult report text for a discussion.
2. The boring location was identified in the field by offsetting from existing reference marks and using a cloth tape
and survey wheel.
3. The borehole was backfilled to site grade following boring completion, and patched with asphalt cold patch mix
when pavement was encountered.
4. The Record of Test Boring represents our interpretation of field conditions based on engineering examination of
the soil samples.
5. The Record of Test Boring is subject to the limitations, conclusions and recommendations presented in the Report
text.
6. "Field Test Data" shown on the Record of Test Boring indicated as 1116 refers to the Standard Penetration Test
(SPT) and means I I hammer blows drove the sampler 6 inches. SPT uses a 140-pound hammer falling 30 inches.
7. The N-value from the SPT is the sum of the hammer blows required to drive the sampler the second and third 6-
inch increments.
8. The soitrock strata interfaces shown m3 the Records of Test Boring are approximate and may vary from those
shown. The soiFrock conditions shown on the Records of Test Boring refer to conditions at the specific location
tested; soilfrock conditions may vary between test locations.
9. Relative density for sands;gravels and consistency for sifts clays are described as follows:
SPT
CPT
SANDSIGRAVELS
SPT
CPT
SILTS/CLAYS
BLOWSIFOOT
KGrCM-
RELATIVE DENSITY
BLO_OWS/EQOT
KG/CM=
CONSISTENCY
0-4
0-16
Very loose
0-1
0-3
Very soft
5-10
17-40
Loose
2-4
4-6
Soft
11-30
41-120
Medium Dense
5-8
7-12
Firm
31-50
121-200
Dense
9-15
13-25
Stiff
50+
over 200
Very Dense
16-30
25-50
Very stiff
>30
a50
Hard
10. Grain size descriptions areas follows:
NAME
SIZE LIMITS
Boulder
12 Inches or more
Cobbles
3 to 12 Inches
Coarse Gravel
'Y< to 3 inches
Fine Gravel
No. 4 sieve to Y4 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
Smaller than No. 200 sieve
11. Definitions related to adjectives used in soil/rock descriptions:
PROPORTION
ADJECTIVE
APPROXIMATE ROOT DIAMETER
ADJECTIVE
<5%
Trace
Less than I/32"
Fine roots
5% to 12%
Little
1/321' to'1."
Small roots
12% to 30%
Some
%" to l"
Medium roots
_
30% to 50%
And
Greater than I"
Large roots
Organic Soils: Soils containing vegetable tissue in various stages of decomposition that has a fibrous to amorphous texture,
usually a dark brown to black color, and an organic odor.
Organic Content <25%: Slightly to Highly Organic; 25% to 75% Muck; >75%: Peat
Yl��l limilli��!l�:l�illi
ll I if =313A���
GF'A INTERNATIONAL
521 N.W. ENTERPRISE DRIVE, PORT ST. LUCIE, FLORIDA 34986
PHONE: (772) 924-3575 - Fax: (772) 924-3580
11 STANDARD PENETRATION TEST BOILING (ASTN1 D-1586)
Clie �t: AJT Construction Consulting, LLC Project No.:15-0986.00
1 Lab No.:
PrcJ ct: Proposed Two -Story Residence - Acquavista Development BLK A Lot 5 Page: I of 1
4434 AlA, St. Lucie County, FL Date: 6/16/2015
Elevt:ion: Existing Grade Drill Rig: Simco-24
Wat Level: not encountered within 0 feet Drilling Fluid commenced at depth of 0 feet Field Party: WN/CS
TES LOCATION SPT @ Lot 5 N27.51546° W80.30810°
Laboratory
Tests
Dept
BIors's/
N
Sample
Layer:
USCS
Description
Passing
Moisture
Organic
(feet
6 in.
Value
No.
From/to
No. 200
Content
Content
0 - 28%
Drilled down to 28'/z feet
--
--------------
I
..............
------
Cone Penetration Test (CPT) also performed
1
i..............
I..............
II-------
I..............
I..............
0
..............
............
I
FA INTERNATIONAL
521 N.W. ENTERPRISE DRIVE, PORT ST. LuclE, FLORIDA 34986
PHONE: (772) 924-3575 - FAX: (772) 924-3580
1 STANDARD PENETRATION TEST BORING (ASTM D-1586)
Clie t: AJT Construction Consulting, LLC Project No.: 15-0986.00
Lab No.:
Proj ict: Proposed Two -Story Residence - Acquavista Development BLK A Lot 5 Page: 2 of 2
4434 AIA, St. Lucie County, FL Date: 6/16/2015
Elev Lion: Existing Grade Drill Rig: Simco-24
Wati Level: not encountered ,vithin 0 feet Drilling Fluid commenced at depth of 0 feet Field Party: WN/CS
TEST
LOCATION SPT @ .Lot 5 N27.51546° W80.30810°
Laboratory
Tests
Dept
(i'ee
Blows/
i 6 in.
N
Value
Sample
No.
Layer:
From/to
I�SCS
Description
Passing
No. 200
Moisture
Content
Organic
Content
2
- ----
....
....
....
....
it
.......
I
-------
4
, _.
- 9--
...--
..............
----
10
12
19
..............
..............
---
14
-----
...
--
...
......
......
------
-16--
....--
---
31
---
...
24
1
2
3
Drilled dense from 25 to 28Y2 feet
7
7i
_.
--
28h - 30
SP
Light grayfins- sand, some cemented sand
2
----
3
Drilled dense from 30 to 33%2 feet
3
3'
3'
33%2 - 35
SP-
Gray fine sand, trace shell, trace cemented'
sand
3
;'
3'
13�1
38Y2 - 40
SP
Gray fine sand, little shell
Boring terminated at 40 feet
GFA INTERNATIONAL
521 N.W. ENTERPRISE DRIVE, PORT ST. UCIE, FLORIDA 34986
PHONE: (772) 924-3575 - FAX: (772) 924-3580
L
CONE PENETRATION SOUNDING (ASTM D 3441)
Ilient:
AJT Construction Consuiting, LLC
Date:
6/12/2015
Project No.:
15-0986.00
IL
.eject:
'K A Lot 5
Proposed Two -Story Residence - Acquavista OL
Lab No.:
4434 AIA, St. Lucie County, Ff.
Field Crew:
WN/CS
Rig ID:
OshKosh
llocation:
CPT @ Lot 5 N27.515451 W80J08091
Page:
1 of I
I
Elevation:
Existing Grade
Cone Bearing, qc (ts1
Friction Ratio, FR
idd Data
III` P+S
q, FR Depth 0 40 80 120 160 200 240
1&�A (meters)
280 320 0 2
4 6 8
5 10 6
5 20 30 2
5 40 71) 0
5 40 70 0
0 55 100 0
1) 55 109 1 5 55 90 1
0 so so I
0 SO 80 0
0 55 109 0
0 55 100 1
5 65 110 1
0 80 141) 1
0 100 160 1
0 100 160 1
0 120 200 2
0 130 200 0
0 160 300 0
0 120 200 0
0 110 200 0
80 140 0
:0 55 100 0
0 35 60 4
0 120 200 0
5 55 90 1
10 so 80 0
3 30 so I
5 30 50 2
;5 65 1610 1
10 90 0 0
�O 100 180 1
0 120 200 1
;0 100 160 0
10 110 200 0
'0 180 340 0
M 240 440 a
;0 250 500 0
;0 250 $00
0
A A
A
5
I.J
0
15
4
6
9 42
20 -
4
2
4
6 25
5-0986,00.4quavista Lots ]-If) (fnrmertv Owens Island) (AJT Consimiction) !GeoiLot 5Uppendicesupp D . SPT(1) & CPY'(I)
V �
�;`:
`s
'.. a a
GW and SW GROUPS. These groups comprise well -graded gravelly and sandy
soils having little or no plastic fines (less than percent passing the No. 200 sieve).
The presence of the fines must not noticeably change the strength characteristics
of the coarse -grained friction and must not interface with it's free -draining
characteristics.
GP and SP GROUPS. Poorly graded gravels and sands containing little of no
plastic fines (less than 5 percent passing the No. 200 sieve) are classed in GP
and SP groups. The materials may 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 the No. 200 sieve) having low or no
plasticity. The plasticity index and liquid limit of soils in the group should 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 with fines (more than 12 percent passing the No, 200 sieve) which
have a fairly high plasticity. The liquid limit and plasticity index should plat above
the "A" line on the plasticity chart.
ML and MH GROUPS. In these groups, the symbol M has been used to
designate predominantly silty material. The symbols L and H represent low and
high liquid limits, respectively, and an arbitrary dividing line between the two set
at a liquid limit of 50. The soils in the ML and MH groups are sandy silts, clayey
silts or inorganic silts with relatively low plasticity. Also included are loose type
soils and rock flours.
CL and CH GROUPS. In these groups the symbol C stands for clay, with L and
H denoting low or high liquid limits, with the dividing line again set at a liquid of
50. The soils are primarily organic clays. Low plasticity clays are classified as
CL and are usually lean clays, sandy clays or silty clays. The medium and high
plasticity clays are classified as CH. These include the fat clays, gumbo clays
and some volcanic clays.
i
OL and OH GROUPS. The soil in the OL and OH groups are characterized by
the presence of organic odor or color, hence the symbol O. Organic silts and
clays are classified in these groups. The materials have a plasticity range that
corresponds with the ML and MH groups.
i
The highly organic soils are usually very soft and compressible and have
undesirable construction characteristics. Particles of leaves, grasses, branches,
or other fibrous vegetable 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.
0