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Environmental •Geotechnical - Construction Materials Testing - Threshold and special Inspections • Plan Review. a Code Compliance
July 16, 2020
Mr. Robert Holterman
10851 S Ocean Drive, Lot 89
Jensen Beach, Florida 34957
Subject: Report of Geotechnical Exploration
Holterman Reilidence
10851 S Ocean Drive, Lot 89, Jensen Beach, Florida
GFA Project No. 20-1127.00
Dear Mr. Holterman:
GFA International, Inc. (GFA) is pleased to submit this report of geotechnical exploration for the above
referenced project. Our services were performed in substantial accordance with our Proposal No. 20-
1127.00 dated June 19, 2020, planned in conjunction with and authorized by you.
Field Exploration
One (1) standard penetration test (SPT) boring, advanced to an approximate depth of 30 feet below
the existing ground surface, was performed for this study. The boring was located by GFA personnel
by estimating distances and offsets from the adjacent properties and other landmarks at the site. The
approximate boring location is shown on the attached Test Location Plan.
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 boring. were advanced using a hand auger due to potential utility line conflicts.
This portion of the boring was performed in general accordance with ASTM D 1452, "Standard
Practice for Soil Exploration and Sampling by Auger Borings." Hand Cone_Penetrometer (HCP) tests
were conducted at one -fool: depth intervals in the auger boring. The HCP test, in conjunction with
information about the soil type, is empirically correlated to the relative density of subsurface soils.
Subsurface Conditions and Laboratory Testina
The soil samples recovered from the boring 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). Selected samples were tested in the laboratory for moisture content (ASTM
D 2216), fines content, or percent dry weight passing the U.S. No. 200 sieve (ASTM D 1140), and
organic content (ASTM D 2974). The laboratory test results are summarized in the following table
and are also contained on the boring log.
607 NW Commodity Cove • Port St Lucie, Florida 34986 • (772) 924-3575 • (772) 9243680 (fax) • www.teamgfa.com
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Report of Geotechnical Exploration July 16, 2020
Holterman Residence -10851 S Ocean Drive, Jensen Beach, Florida Page 2
GFA Project No. 20-1127.00
The subsurface conditions encountered in the boring generally consisted of loose to medium dense
fine sand (SP) and fine sand with silt (SP SM) to the boring termination depth. The results of the
laboratory testing indicated that the soil layers between depths of approximately 4.5 and 8 feet had
organic contents of 2.7 and 5.5 percent. Soils having similar organic contents are generally not
considered problematic with regard to experiencing excessive settlement resulting from conventional
single -story residential structure foundation loads.
On the date of our fi Id a ploration (July 9, 2020), groundwater was encountered in the boring a tan
approximate depth 4.3 eet below the existing ground surface. Note that the groundwater table will
fluctuate seasonally epe ding upon local rainfall and other site specific and/or local influences,
including tidal variations in the adjacent Jensen Beach to Jupiter Inlet Aquatic Preserve.
Recommendations
For conventional s Ilow, foundation systems, it is GFXs; opinion that a maximum allowable soil
bearing pressure o 50Q psf is appropriate for the proposed structure subject to the limitations noted
herein. We recommend t at the bottom of the footings bear at a depth of at least 12 inches below
finish grade measured from the lowest adjacent grade. We also recommend a minimum footing width
of 18 inches for spread footings.,and 16 inches for mondlithic footinas. ut not less tt,a R
This report does not state or imply that the foundation soils at the gearing level will remain in the same
condition in which they were found during .the subsurface exploration activities. Exposure to the
environment may weaken the bearing soils if the foundation excavations remain open for an extended
period or if the soils are exposed to rainfall. Therefore, it is recommended that the excavations for the
wall and column footings be performed to final grade and foundation concrete be placed as soon as
practicable to reduce the potential for deterioration of the bearing soils.
GFA estimates that approximately 1 to 2 feet of fill will be required to raise the building pad to design
grade. The 2 feet of soils below existing grade,. below. the bottom of all new footing excavations and
slabs, and all fill material should be compacted to at least 95 percent of the modified Proctor (ASTM D
1557) maximum dry density prior to placement of concrete for the footings.
During site preparation, foundations and the below grade remains of any structures that are within the
footprint of the new residence should be removed. Similarly, utility or irrigation lines within the limits of
the proposed construction should also be removed or properly abandoned so that they will not
adversely impact new overlying structures.
(, CA
Report of Geotechnical Exploration July 16, 2020
Holterman Residence -10851 S Ocean Drive, Jensen Beach, Florida Page 3
GFA Project No. 20-1127.00
Closure
Th' port has beer p�reR� ,oAr th clusive se of Mr. Robert Holterman for th sin fe-
tory. res' _ 10851 S Ocean Dnve of 89, in Jensen Beach, Florida. Ob ces were
>=ovi ed m actor ante wi gen y-a�C local geotechnical engineering practices; no other
warranty is expressed or implied.
This report does not reflect any variations in soil conditions which may exist away from the boring
performed at the site. While the: boring is representative of the subsurface conditions at its location
and vertical reach, local variations characteristic of the subsurface soils of the region are common.
The delineation between soil types shown on the boring log is approximate and the descriptions
represent our interpretation of the subsurface conditions at the designated boring location on the
specific date drilled.
GFA should be provided the opportunity to review the final foundation design plans and specifications
to determine whether 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.
Any third -party reliance of this 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.
We appreciate the opportunity to be of service to you during this phase of the project and look forward
to a continued association. Please contact the undersigned if you have any questions or comments,
or if we may further assist you as your plans proceed.
Respectfully Submitted,
ISFA INTERNATIONAL, INC.
Florida Certificate of Authorization No. 4930
Digitally signed by
John Kent
John Ke n:tDate: 2020.07.16
08:15:54-04'00'
John Kent, P.E.
Senior Project Engineer
Florida Registration No. 63218
This item tms 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.
Attachments: Test Location Plan
SPT Boring Log
Notes Related to Boring Records
Distribution: Mr. Robert Holterman
Erik Soderstrom, E.I.
Geotechnical Department Manager
a pdf
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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 backfilied 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 an the Log of Boring records refer
to conditions at the specific location tested. Soilfrock conditions may vary between test locations.
9. Relative density for coarse -grained sods (sands/gravels) and consistency forfine-grained soils (silts/clays)
are described as follows:
Coarse Grained Soils
(Sands and Gravels)
Fme Grained Soils
(Sift and
Clays)
SPT
N-Value
HCP Value
(kg/cm2)
CPT Value
(tsf)
Relative
Density
SPT
N Value
HCP Value
(kg/cm2)
CPT Value
Consistency
0-4
0-16
0-20
Very Loose
0-2
a 20
0-3
Very Soft
5-10
17-36
21-40
Loose
3-4
21-35
4-6
Soft
1.1-30
37-116
41-120
Med. Dense
5-8
>35
7-12
Firm
31-50
117-196
1 121200
1 Dense
9-15
1
1 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 Sae Limits
Boulder
Greater the 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 Ile
Fine roots
5% to 12%
Little
1/31" to
Small roots
12% to 30%
Some
'/a to 1"
Medium roots
30% to 50%
And
Greater than 1"
La!Re 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 Hi hl O anic; 25% to 750/6: Muck; >75%: Peat
19
607 NInternational,mods y C LOG OF BORING B-1
607 NW Commodity Cove
Port Saint Lucie, Florida 34986 PAGE 1 OF 2
(772) 924-3575
44vw por
CLIENT Mr. Robert Holterman PROJECT NAME Holtennan Residence
PROJECT NUMBER 20-1127.00 PROJECT LOCATION 10851 S Ocean Drive Lot 89 Jensen Beach Florida
DRILLING CONTRACTOR GFA Intemational Inc. HOLE DEPTH 30 ft HOLE DIAMETER 3 in
DRILLER JB/SP DATE STARTED 7/9/20 COMPLETED 7/9120
DRILL RIG Simco GROUND WATER LEVEL --SAT TIME OF DRILLING 4.30 ft
METHOD SPT LAiiTUDE LONgTUDE
NOTE: HAMMERTYPE
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GFA International, Inc.
LOG OF
BORING B-1
607 NWW Commodity Cove
Port Saint Lucie, Florida M86
PAGE 2 OF 2
(772)924-3575
Ndi1®�
CLIENT Mr. Robert Holterman
PROJECT NAME Holterman Residence
PROJECT NUMBER 20-1127.00
PROJECT LOCATION 10851 S Ocean Drive Lot 89, Jensen Beach Florida
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Gray fine sand, trace silt and shell (SP)
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Light gray fine sand with silk little shell and cemented sand (SP-SM)
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Bottom of borehole at 30.0 feet
Test Location Plan
PROJECT NO: 20-1127.00
Le end,
Holterman Residence
10851 S Ocean Drive, Lot 89, Jensen Beach, Florida
DRAFTED BY- JR REVIEWED BY: JK DATE: 7115/2020
P7 Approximate 30' Standard Penetration Test Boring Location
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