HomeMy WebLinkAboutGEOTECHNICAL EXPLORATION REPORTi
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GFA INTERNATIONAL
FLORIDA'S LEADING. ENGINEERING SOURCE
Report of 'Geotechnical Exploration
Ivany Residence Pool
113 Dunes Island Cove RECEIVED
Jensen Beach, Florida MAR 0 8 ma
PErmltting Deportment
February 26, 2019 St. Lucie County
GFA Project No.: 19-1792.00
For: Team Parks, Inc. GCANNED
BY
St Lucie County
e6PP.
Florida's
Giotechnlcal • Construction Materials Testing • Threshold and Special Inspections • Plan Review &
February 26, 2019
mr. I i rreitas
Team Parks, Inc.
611 SE Palm Beach Road
Stuart, Florida 34994
Subject: Report of Geotechnical Exploration
Ivany Residence Pool
113 Island Dunes Cove
Jensen Beach, Florida
GFA Project No. 19-1792.00
Dear Mr. Freitas:
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 (1.9-1792.00), planned in conjunction
with and authorized by you.
EXECUTIVE SUMMARY
The purpose of our subsurface exploration was to classify the nature of the subsurface soils and
general geomorphic conditions at the site and evaluate their impact upon the proposed
construction. This report contains the results of our subsurface exploration and our engineering
interpretations of these with respect to the project characteristics described to us, including
providing recommendations for foundation design and site preparation.
Per our recent telephone discussions and email correspondence with you, GFA understands
that anew residence and pool are planned for construction at the above reference property.
The construction of the residence is currently underway and is being supported by conventional
shallow foundation. system. However, because of the location of the pool on the property relative
to the adjacent Jensen Beach to Jupiter Inlet Aquatic .Preserve, the pool vessel must be
supported by deep foundations. GFA understands that helical pile foundations have been
selected to support the pool.
The provided Pool/Spa Piling & Layout Plan prepared by O.P. Custom Pools (Sheet 2 of 3)
dated October 25, 2018 indicates that 15 helical piles will be installed to support the pool and
spa. The piles have been designed for a 15-ton allowable (30-ton ultimate) capacity.
The recommendations. provided herein are based. upon the above considerations. If the stated
conditions are incorrect or if the project description is revised, please inform GFA so that we
may review our recommendations with respect to any modifications.
607 NW Commodity.Cove Port St..Lucie, Florida„ 34986. - . (772):924.3575 • . (772) 924.3580
OFFICES THROUGHOUT FLORIDA
4,;
Ivany Residence Pool
113 Island Dunes Cove, Jensen Beach, Florida
GFA Project No. 19-1792.00
Geotechnical Exploration Report
February 26, 2019
Page 2 of 8
One (1) standard penetration test (SPT) boring, advanced to a depth of approximately K feet
below the existing ground surface, was completed for this study. In general,, the subsurface soil
conditions encountered in the at the boring. location consisted of medium dense fine sand (SP)
and fine sand with clay (SP-SC) to the, boring termination depth. As an exception, a layer of
very loose clayey fine sand (SC) was present from a depth of approximately 18 to 22 feet below
the existing ground surface. In addition, concrete was encountered from a depth of 3 and 3.5
feet in the boring. Please refer to Appendix D - Record of Test Borings for detailed account of
the boring.
Based on the results of the boring, it is GFA's opinion that Helical piles are an acceptable deep
foundation configuration for support of the new pool. To obtain the design 15-ton allowable (307
ton ultimate) axial capacity, the helical piles will likely have to be installed and seated into the
medium dense fine sand (SP) and fine sand with clay (SP-SC) soil strata encountered from
about 22 to 30 feet below existing grade. Note that the length of the piles could extend beyond
30 feet before achieving the required torque and corresponding capacity.
We appreciate the opportunity to be of service to you on, this
continued association. Please do not hesitate to contact us
comments, or if we may further assist you as your plans proceed.
Respectfully Submitted,
GFA International, Inc.
Florida CONgNaKF�Ar!';orization No. 4930
�� No. 632181- '•. �(���
STATE OF ��� z—Ve—PI)
63218
Distribution: Mr. TJ Freitas —Team Parks, Inc.
project and look forward to a
if you have any questions or.
Rick Martens
Project Manager
1 pdf
i
Ivany Residence Pool Geotechnical Exploration Report
113 Island Dunes Cove, Jensen Beach, Florida February 26, 2019
! GFA Project No. 19-1792.00 Page 3 of 8
TABLE OF CONTENTS
1.0 INTRODUCTION..................:...........................::............................................:....................4
1.1 Scope of Services............................................................................................................4
1.2 Project Description...........................................................................................................4
12.0 OBSERVATIONS ....
........................
:..:......r...................
.................
.............
.......................... 4
2.1 Site Description................................................................................................................4
2.2 Field Exploration..............................................................................................................:5
2.3 Visual Classification .............................. :...... :............................ ........................................ 5
2.4 'Geomorphic Conditions ........................ ..............
............................................................... 5
2.5 Hydrogeological Conditions......................:........................:...............................:..............6
3.0 ENGINEERING EVALUATION AND RECOMMENDATIONS...........:...................................6
3.1 General ... ........................................ :..................................... :..................... :.................... 6
3.2 Helical Pile Foundations....::...:............................::.......:::.................................................6
4.0 REPORT LIMITATIONS .......................... :.................................... ......................................... 8
! 5.0 BASIS FOR RECOMMENDATIONS ................. :...... ...................................... :..................... 8
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
I
FP
Ivany Residence Pool,
113 Island Dunes Cove, Jensen Beach, Florida
GFA Project No. 19-1792.00
1.0 INTRODUCTION
1.1 Scope of Services
Geotechnical Exploration Report
February 26, 2019
Page 4 of 8
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 construction. The following scope of services is provided within
this report:
Prepare a boring log 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 helical pile
foundation support for the proposed pool and spa.
4. Provide recommendations with respect to helical pile foundation supportbf the, pool and
spa, including .anticipated axial load capacities, bearing elevations, and estimated total and
differential settlement.
1.2 Project Description
Per our recent telephone discussions and email correspondence with you, GFA understands
that a new residence and pool are planned for construction at the above reference property:
The construction of the residence is underway and is being supported by conventional shallow
foundation system. However; because of the location of the pool on the property relative to the
adjacent Jensen Beach to Jupiter Inlet Aquatic Preserve, the pool vessel must be supported by
deep foundations. GFA understands that helical piles have been selected to support the pool.
The provided Pool/Spa Piling & Layout Plan prepared by O.P. Custom Pools (Sheet 2 of 3)
dated October 25, 2018 indicates that 15 helical piles will be installed to support the pool and
spa. The piles have been designed for a 15-ton allowable (30-ton ultimate). capacity.
The recommendations provided herein are based upon the above considerations. If the stated
conditions'are incorrect or if the project description is revised, please inform GFA so that we
may review our recommendations with respect to; any modifications.
2.0 OBSERVATIONS
2.1 Site Description
At the time of our field exploration, a new residence was under construction at the property.
Other residential properties were located adjacent to the site. The Jensen Beach to Jupiter Inlet
Aquatic Preserve borders the west side of the property.
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Ivany Residence Pool Geotechnical Exploration Report
113 Island Dunes Cove; Jensen Beach; Florida February 26, 2019
GFA Project No. 19-1792.00 Page 5 of 8
2.2 Field Exploration
One (1) standard penetration test (SPT) boring, advanced to a depth of approximately 30 feet
below the existing ground surface, was -completed for this study. The locations of the borings
are illustrated in Appendix B - Test Location Plan.
The Standard Penetration Tests (SPT) were performed in general . accordance with ASTM D
1686, "Penetration Test and .Split -Barrel Sampling of Soils." The SPT.test procedure consists of
driving a 1.4-inch I. D. split -barrel sampler into the soil profile using a 140-pound hammer falling
30 inches. The number of blows per foot, for the second and third 6-inch increment, is referred
to as the N-value. The N-value has been empirically correlated with various soil properties and
provides an indication of soil, strength.
The soil samples recovered from the boring were visually classified and their stratification is
illustrated on the boring log in Appendix D. Note that the soil boring data reflect information
from the specific test location only and .soil conditions may vary between the strata.. interfaces
indicated on the. log. _The boring depth was based upon our knowledge of vicinity soils and
confined to the zone of soil likely to be influenced by the proposed helical pile foundations..
Site specific survey staking of the boring was not provided for our field exploration. The boring
was located at the site using the provided Pool/Spa Piling & Layout Plan and estimated
distances and relationships to -other site features.
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 will be pleased to perform these services
for an additional fee, if required.
2.4 Geomorphic Conditions
The geology of the sit e.as mapped on the USDA Soil Survey website consists of Canaveral fine
sand, 0 to 5 percent slopes (10). These are sandy soils and organic soils are not indicated.
The Soil Survey generally extends to a maximum depth of 80 inches below ground surface and
is not indicative of deeper soil conditions.
The boring log resulting from our field exploration is presented in Appendix D - Record of Test
Borings. The boring log contains the soil descriptions and the standard.,penetration test (SPT)
N-values logged during the drilling and sampling activities. The soil classifications and
descriptions shown on the log are generally based upon visual characterizations of the
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Ivany Residence Pool Geotechnical Exploration Report
1113 Island Dunes Cove, Jensen Beach, Florida February 26, 2019
GFA Project No. 19-1792.00 Page 6 of 8
recovered samples using the Unified Soil Classification System. See Appendix E - Discussion of
Soil Groups, for a detailed description of various soil groups:
In general, the subsurface soil conditions encountered in the at the boring location consisted of
medium dense fine sand (SP) and fine sand with clay (SP-SC) to the boring termination depth.
!As an exception, a layer of very. loose clayey fine sand (SC) was present from a depth of
approximately 18 to 22 feet below. the existing, ground surface. In addition, concrete was
encountered from a depth of 3 and 3.5 feet; in the boring.
2.5 Hydrogeological Conditions
On the date of our field exploration, the groundwater table was encountered. -at a depth of
approximately 7.5 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 levels in 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.
1 3.2 Helical Pile Foundations
i
Based on the results of the boring, :it is GFA's opinion that helical piles are an acceptable deep
foundation configuration for support of the new pool. Helical piles consist of galvanized steel
shafts with helical flight augers on the, bottom shaft. The shaft sections are bolted together as they
are augered into the subsurface. The torque applied to the piers during drilling is correlated to the
GfP
Ivany Residence Pool
113 Island Dunes Cove, Jensen Beach, Florida
GFA Project No, 19-1792.00
Geotechnical Exploration Report
February 26, 2619
Page 7 of 8
axial compression capacity of the helical pile. The shafts are cut to the appropriate cut-off
elevation, and typically pile caps,. grade beams, or footings are cast. on the top of the helical
piles.
To obtain the design 15-ton allowable (30-ton ultimate) axial capacity, the helical piles. will likely
have to be installed and seated into the medium dense fine sand (SP) and fine.. sand .with clay
(SP-SC) soil strata encountered from approximately 22 to 30 feet below, existing grade. Note
that the length of the piles could 'extend beyond 30 feet before achieving the required torque
and corresponding, capacity.
GFA recommends that the piles be spaced at least 3 diameters (largest helical diameter) apart
center -to -center. Each pile must be installed with a minimum of twice its design capacity. The
In accordance with Section 1810.3.3.1.9 of the 2017
allowable axial design load,,P., of helical piles should.
I
Pa = 0.5 P. (Equation 1874)
where P is the least value of:
Florida Building, Code, Sixth Edition, the
be determined as follows:
1. Sum of the areas of the helical bearing plates times the ultimate bearing capacity of the
soil or rock comprising the bearing stratum.
2. Ultimate capacity determined from well -documented correlations with installation
torque.
3. Ultimate capacity determined from load tests.
4. Ultimate axial capacity of pile shaft.
5. Ultimate axial capacity of pile shaft couplings.
6. Sum of the ultimate axial capacity of helical bearing plates affixed to the pile..
Helical pile design and installation is proprietary in nature. The locations and required capacity of
the piles must be designed by a structural engineer or other qualified professional. It is
recommended that a representative of GFA monitor the helical pile installation 'in
accordance with the Florida.Building Code..
We estimate that .properly designed and installed helical piles will experience total in-service
settlements on the order of one-half (0.5) inch or less. Differential settlements are estimated not
to exceed one -quarter (0.25) inch.
Required fill and backfill around pile caps and grade. beams should consist of sand having less
than 5 percent fines (percent of dry weight passing the U.S. -No. 200 sieve). The fill should be
placed in 12-inch maximum thick lifts with each lift compacted to at least 95 percent of modified
Proctor (ASTM D 1557) maximum dry density. Achieving the recommended level of compaction
should be confirmed by performing field density tests.
GfP
Ivany ResidencePool Geotechnical Exploration Report
113 Island Dunes Cove, Jensen Beach,. Florida February 26, 2019
GFA Project No. 19-1792.00 Page 8 of 8
4.0 REPORT LIMITATIONS'
This consulting report has been prepared for the exclusive use' of Team Parks, Inc., .the current
I property owners, and .other members of the design team for the proposed pool at 113 Island
Dunes Cove in Jensen Beach, Florida. This report has been prepared in accordance with
generally accepted local geotechnical engineering practices; no other warranty is expressed or
implied.
The evaluation submitted in this report is based in part upon the data collected during a field
exploration: However, the nature and extent of variations throughout the subsurface profile. may
not become evident until construction. If variations then appear evident, it may be necessary to
reevaluate, information and professional opinions as provided in this report. In the event
changes are made in the nature, design, or location of the proposed pool, 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.
i
GFA should be provided the opportunity to.review, the final design 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 boring performed at the location indicated on the Test Location ,Plan in Appendix B.
This report does not reflect any variations which may occur away from "the boring, While the
boring is representative of the subsurface conditions at its location and for its vertical. reach,
local variations characteristic of the subsurface soils of the region are anticipated and may be
encountered. The delineation between soil types shown on the boring log is approximate and
the descriptions represent our interpretation of the subsurface conditions at the designated
boring location on the specific date drilled.
Any third -party reliance of our geotechnical report or parts thereof is strictly prohibited without
the expressed written consent of GFA International, Inc. The applicable SPT methodology
(ASTM D .1586.) used in performing our boring, 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.
6FP
Appendix A - Vicinity Map
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Vicinity Map
113 Island Dunes Cove, Jensen Beach, FL
GFA Project No. 19-1792.00
Appendix B - Test Location Plan
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Approximate Standard Penetration Test (SPT) Boring Location
Appendix C - Notes Related to Borings
GfA
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 data 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 forfine-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/cm)
CPT Value
(tsf)
Consistency
4
00-20
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.
eryStiff
>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
/4 to 3 inches
Fine Gravel
No. 4 sieve to 3/4 inch
Coarse Sand
No. 10 to No. 4 sieve
Medium Sand, -
No. 40 to No. 10 sieve
Fine Sand
No. 200 to No. 40 sieve
Fines Silt/Cla
Smaller than No. 200 sieve
91. Definitions for modifiers used in soil/rock descriptions:
Proportion
Modifier
Approximate Root Diameter
Modifier
<5%
Trace
Less than /32"
Fine roots
5% to 12%
Little
V32" to V4"
Small roots
12% to 30%
Some
'/4" to 1"
Medium roots
30% to 50%
And
Greater than 1"
Lame
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
GfR
Appendix D - Record of Test Borings
GFH
GFA lntemational LOG OF BORING SPT-1
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607NW Commodity cove
PAGE 1 OF 1
Port Saint Lucie, FL 34986
..LL..7729243575
' (t'eeAt10�!
CLIENT Team Parks Inc. PROJECTNAME Ivan Residence - Pool
PROJECT NUMBER 19-1792.00- PROJECT LOCATION 1131sland Dunes Cove Jensen Beach, FL
DRILLING CONTRACTOR _GFAInternational Inc. HOLE DEPTH 30ft. HOLE DIAMETER
DRILLER PMIBTILB DATE STARTED 2120119 COMPLETED 2120119
DRILL RIG Simco GROUNDWATER LEVEL: -VAT TIME OF DRILLING 7.50 ft
METHOD SPT LATITUDE LONGITUDE
NOTE: HAMMERTYPE
♦ SPT N VALUE A
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a 0!
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20 .40 60 80
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MATERIAL DESCRIPTION
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❑ FINES CONTENT (%) ❑
20 40 60 80
Brown fine send (SP)
1
1
s
12
a
a
3.0
2
40
32
72
3.5 ncrete
Brown fine sand, little day (SP)'
20
5
16.0
3
20
20
40
17
Brown fine sand with day (SP-SC)
7 -
4
4
s
6
6
11
!:9.5
L
5
166
15
31
I 10
15
Gray fine sand, some shell (SP)
13
6
7
16
15
I
1
� I
1
18.0
Gray clayey fine sand with shell (SC)
�
I
7
;
2
' 20
122.0
I
Gray fine sand, little clay, some shell (SP)
i
s
8
10
18
' 25
i I
27.0
Gray fine sand with day, trace shell (SP-SC)
'.
i
16
{
30.0
9
'112
26
Bottom of borehole at 30.0 feet._
Appendix E - Discussion of Soil Groups
GfR
DISCUSSION OF SOILGROUPS
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 50and
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.
GFP
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.
6fP