EXHIBIT_B_GEOTECH_REPORT.pdf

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SPECIFICATIONS FOR PROJECT TO ENGINEER, PROCURE, AND CONSTRUCT COVERED PARKING
Solicitation number
FKEC BID #26-04
Issued by
Monroe County, Florida

About this file

This is a geotechnical exploration report prepared by Nutting Engineers of Florida, Inc. for Florida Keys Electric Cooperative regarding subsurface conditions at 91630 Overseas Highway in Tavernier, Florida. The report documents findings from a Standard Penetration Test boring conducted to a depth of 20 feet below ground surface at the proposed site of a covered storage structure. The exploration revealed dense to medium dense limestone fragments with fine sand to approximately four feet depth, underlain by medium hard to very hard limestone with fine sand extending to 20 feet. The groundwater level was encountered at approximately 2.5 feet below the existing ground surface. The geotechnical engineer recommends that shallow foundations be designed for an allowable bearing pressure of 2,500 pounds per square foot with minimum footing widths of 16 inches for continuous footings and 24 inches for individual footings. The report indicates that anchor piles will likely be required per Monroe County Code of Ordinances Section 6-147, which mandates all structures be anchored into natural rock with a 14-inch minimum diameter auger socket and 3-foot minimum embedment into the limestone formation.

The report provides detailed recommendations for augercast anchor pile installation, specifying that 14-inch diameter piles would provide approximately 10 tons of compressive capacity and 16-inch diameter piles would provide approximately 12 tons of compressive capacity when installed to three feet embedment depth into the limestone formation (approximately seven feet below existing grade). Site preparation requirements include removal of all surficial topsoil, trees, roots, and debris within the construction area and extending at least five feet beyond the footprint limits, with compaction of the stripped surface to at least 98 percent of modified Proctor maximum dry density to a depth of 12 inches. The report specifies that the piling contractor's proposed pile design must be reviewed by Nutting Engineers prior to installation, and at least three production piles must be installed under the presence of the geotechnical engineer. The report estimates total foundation settlements of less than one inch and differential settlement between adjacent foundations of approximately half an inch, with anticipated distortions along wall footings not exceeding 1 in 500. Nutting Engineers recommends ongoing engagement during foundation design, final design review, and full-time observation during earthwork and foundation construction phases.

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REPORT OF

GEOTECHNICAL EXPLORATION

PROPOSED STORAGE STRUCTURE

91630 OVERSEAS HIGHWAY

TAVERNIER, FLORIDA 33070

FOR

FLORIDA KEYS ELECTRIC COOPERATIVE

91630 OVERSEAS HIGHWAY

TAVERNIER, FLORIDA 33070

PREPARED BY

NUTTING ENGINEERS OF FLORIDA, INC.

24478 OVERSEAS HIGHWAY

SUMMERLAND KEY, FLORIDA 33042

ORDER NO. 2327.3

DECEMBER 2025

24478 OVERSEAS HIGHWAY ∙ SUMMERLAND KEY, FL 33042 ∙ 305-824-0060 ∙ FAX 305-824-8827

St. Lucie 772-408-1050 ∙ Broward 954-941-8700 ∙ Palm Beach 561-736-4900

December 18, 2025

Mr. Scott Newberry

Florida Keys Electric Cooperative

91630 Overseas Highway

Tavernier, Florida 33037

Phone: 305-852-2431 Email: scott.newberry@fkec.com

Re: Report of Geotechnical Exploration Services

Proposed Storage Structure

91630 Overseas Highway

Tavernier, FL 33070

Dear Mr. Newberry:

Nutting Engineers of Florida, Inc. (NE), has performed a Geotechnical Exploration at the referenced site in Tavernier, Florida. The purpose of this exploration was to obtain information concerning the site and subsurface conditions at specific locations in order to provide site preparation and foundation design recommendations for support of the planned construction. The following presents our findings and recommendations.

PROJECT INFORMATION

Per the email from Nick Lyons of Florida Keys Electric Cooperative dated November 19, 2025 and review of the aerial provided, we understand that plans for this project include constructing a covered storage structure (pole barn style) at the referenced site. The structure will be single-story, without a concrete slab-on-grade floor, and will consist of three walls and a roof, with one side of the building being exposed without a wall. The exposed side of the structure will consist of 14 to

15-foot-tall garage door openings.

NE should be notified in writing by the client of any changes in the proposed construction along with a request to amend our foundation analysis and/or recommendations within this report as appropriate.

GENERAL SUBSURFACE CONDITIONS

Subsurface Soil Exploration

The exploration of subsurface conditions included site observation, review of available data such as the Soil Survey of Monroe County and one (1) Standard Penetration Test boring (ASTM D-

1586) to a depth of twenty feet below the existing ground surface. The location of the test boring is indicated on the attached Boring Location Plan, presented in the Appendix. The test boring report is also presented in the Appendix of this report.

mailto:scott.newberry@fkec.com

The test boring locations were established in the field using approximate methods; namely, a measuring wheel and available surface controls, therefore the locations should be considered approximate.

The appended boring log presents information and descriptions of the subsurface conditions at the specific test boring location. Representative samples collected from the SPT boring were visually reviewed in the laboratory by a geotechnical engineer in order to confirm the field classifications.

The Standard Penetration Test N-values (the number of successive blows required to drive the sampler into the soil one foot) are presented on the individual boring log. The SPT N value has been empirically correlated with various soil properties and is considered to be indicative of the relative density of cohesionless soils and the consistency of cohesive soils. The correlation of penetration resistance with relative density is presented in the Soil Classification Criteria attached in the Appendix.

Soil Survey Maps

As part of the geotechnical study, we reviewed the Department of Agriculture Soil Survey of

Monroe County. These SCS maps provide qualitative information about potential general shallow soil conditions in the project vicinity. This information was derived from approximately 6 ft. deep manual auger borings, aerial photo and surface feature interpretation at some point in the past (mid

1980’s to early 1970’s). The SCS data may or may not reflect actual current site conditions. As indicated in the Monroe County Soil Survey Map, Pennekamp gravelly muck-Urban land complex, 0 to 2 percent slopes, extremely stony, was identified for this site. About fifty percent of the complex is comprised of Pennekamp gravelly muck, while forty-five percent is comprised of

Urban Land. The Pennekamp series is present on islands adjacent to areas of water throughout the

Keys. Individual areas are subject to flooding from hurricanes and other tropical storms. The typical profile of the Pennekamp series consists of gravelly muck to a depth of about 3 inches, underlain by lithic bedrock to depths of about 4 to 20 inches. We note that the maximum depth of the soil survey was approximately six feet.

Test Boring Results

In general, the test boring recorded dense to medium dense light brown and gray limestone fragments with fine sand to a depth of approximately four feet, underlain by medium hard to very hard light brown limestone with fine sand to twenty feet, the maximum depth explored. A detailed description of the soil/rock interlayering is given on the test boring logs in the Appendix.

Rock Formation Note:

Generally, rock in the Florida Keys area may include limestone or sandstone which have irregularities and discontinuities including vertical and horizontal solution features, varying surface and bottom elevations, and varying degrees of hardness. The rock features may also contain intervening sand and other material filled lenses. Solution features can be very common in rock strata in Southeast Florida and the Florida Keys. Also given the brittle nature of some rock strata, rocks may readily shatter when hit by the split spoon, resulting in low blow counts. Despite this, these strata may present significant resistance to excavation.

Groundwater Information

The immediate groundwater level was measured at the boring locations at the time of drilling. The groundwater level was encountered at a depth of approximately two and a half feet below the existing ground surface.

The immediate depth to groundwater measurements presented in this report may not provide a reliable indication of stabilized or longer-term depth to groundwater at this site. Water table elevations can vary dramatically with time through rainfall, droughts, storm events, flood control activities, nearby surface water bodies, tidal activity, pumping and many other factors. For these reasons, this depth to water data should not be relied upon alone for project design considerations.

ANALYSIS AND RECOMMENDATIONS

The test boring performed for this project generally revealed limestone fragments with fine sand extending to a depth of about four feet within the proposed storage structure, underlain by medium hard to very hard limestone with fine sand throughout the soil profile. Therefore, it is our opinion that shallow foundations should provide sufficient support for the proposed construction, provided foundation criteria and site preparations are followed as discussed in this report.

Additionally, per Monroe County Code of Ordinances, Section 6-147 which indicates if the buildings are located within an area covered by this Ordinance, anchor piles will be required. The

Ordinance states in part: "All structures or building foundations shall be anchored/socketed into natural rock. This includes, but is not limited to, auger cast concrete piles, precast concrete piles or wooden piles. All concrete piling shall have full depth reinforcing to effectively resist the internal forces induced by the design loads, without failure. All piling shall be anchored to the natural rock with a 14-inch minimum diameter augured socket and a minimum embedment of 3 feet”. We were not provided information concerning whether this Ordinance applies to this project. Therefore, we should be informed to provide additional input if this portion of the Code applies. The structural engineer should review the Ordinance to confirm compliance with the

Code. The following sections present our recommendations for site preparation and foundation support.

Based on the above information, new footings will need to be installed to a below existing ground depth of at least two feet and anchor piles, if needed, should be installed to a depth of three feet below the top of the limestone formation (pile tip elevation of approximately seven feet below existing ground surface) to comply with the building code requirements. Discussions should be held with all interested parties to determine details concerning structural loading conditions and other factors that may be needed as part of the design.

Augercast Anchor Pile Recommendations

Based on the results of our analysis, if augercast anchor piles are installed to a tip depth of three feet into the limestone formation (seven feet below existing grade) per Monroe County Code of

Ordinances, Section 6-147, the resulting compressive capacity is estimated to be on the order of

10 and 12 tons using either a 14-inch or 16-inch diameter augercast pile section. The actual depths should be expected to vary depending on the drilling conditions encountered during installation of these piles. The depths of the pile tips as recommended in this report are based on the ground surface elevations as they existed at the time the test borings were performed. The piling contractor shall submit the proposed pile design to Nutting Engineers of Florida, Inc. for their review and comment prior to proceeding with pile installation.

The Florida Building Code (FBC) requires that any piles designed for greater than 40 tons should be load tested in order to verify the pile capacity. Therefore, a pile load test will not be required for this project as described in the FBC. The following table presents the results of our pile capacity analysis.

AUGERCAST PILE CAPACITY TABLE

Pile

Diameter

(Inches)

Depth Below Top of

Limestone

Formation* (Ft)

All. Compr.

Capacity

(Tons)

All. Tension

Capacity

(Tons)

Minimum

Grout Strength (psi)

(min. 0.3 f ’c)

14 3 10 5 5,000

16 3 12 6 5,000 *Depth of embedment of the pile into the formation. Note that depth of the surface of the limestone may vary.

Anchor Pile Observations

At least three production profile piles within the structure shall be installed in the presence of the

Nutting project geotechnical engineer. Pile installation criteria for the remainder of the production piles will be provided after this time. It is important that the installation of all piles be under the full-time observation of a representative of Nutting Engineers to verify the piles will support the structural loading.

Anchor Pile Reinforcement

We recommend that at a minimum, one full length #6 reinforcing steel bar utilizing centralizers be installed. The structural engineer will provide specific steel reinforcing requirements based on the loading conditions. The project structural engineer will determine the locations of the pile foundation system. Discussions should be initiated between the owners, structural engineer, contractor, and Nutting Engineers to provide detailed specifications for the foundation installation work once structural loading conditions are determined.

Foundation Design – Shallow Foundations

Once the site preparation recommendations have been implemented as described in this report, the site may be developed with the proposed storage structure using a shallow foundation designed for an allowable bearing pressure of 2,500 pounds per square foot. A higher bearing capacity may be possible, however, we would need to know details concerning the foundation design.

We recommend a minimum width of 16 inches for continuous footings and 24 inches for individual footings, even though the soil bearing pressure may not be fully developed in all cases. The shallow foundations should be sized, and reinforcement must be provided in accordance with the structural engineer’s requirements, the current Florida Building Code and other applicable standards. The foundations should be constructed in accordance with the local building codes and good standard practice.

Foundation Settlement

Foundations designed and constructed in accordance with the recommendations of this report are estimated to sustain total settlements of less than one inch. Settlement of the foundations will occur as an elastic response of the soil to the loads applied. In this case, nearly all of the settlement of the foundations due to dead loads is expected to take place during construction. The portion of the settlement due to the live load of the structure will generally take place soon after the first application of this load.

Differential settlement between adjacent foundations should be approximately half of an inch.

Distortions that occur along the wall footings due to differential settlement should not be more than 1 in 500.

Site Preparation

Any surficial topsoil, trees and roots, debris from the clearing operations, and any unsuitable soils as determined by the Geotechnical Engineer will need to be completely removed within the construction area and to a lateral distance of at least 5 feet beyond the footprint limits. A Nutting

Engineer's representative should be present to observe that the stripping and excavation operations are performed as we have discussed herein.

Upon approval by the geotechnical engineer, the stripped surface (no fill added at this time) should then be compacted until a density equivalent to at least 98 percent of the modified Proctor maximum dry density (ASTM D-1557) is achieved to a depth of at least 12 inches below the compacted surface. The soils should be at an acceptable moisture content to allow for proper compaction. Any structural fill needed to bring the site to construction grade may then be placed in lifts not exceeding twelve inches in loose thickness. Each lift should be thoroughly compacted until densities equivalent to at least 98 percent of the modified Proctor maximum dry density are uniformly obtained. Fill should consist of granular soil, with less than 10% passing the No. 200 sieve, free of rubble, organics (5% or less) clay, debris and other unsuitable material.

The fill should have ASTM designation (D-2487) of GP, GW, SP, SW, GP-GM, GW-GM, SP-

SM or SW-SM with a maximum particle size of no more than 3 inches or as otherwise approved by Nutting Engineers.

We have provided a table of soil properties for the soils encountered. The table is based on visual classification, empirical relationships and our experience with similar soil conditions. If more exact values are needed, specific testing should be performed.

Table 1. General Subsurface Soil Parameters

Soil Description

Soil Unit Weight

(pcf)

Internal

Friction

Angle, φ (degrees)

Earth Pressure

Coefficients (Rankine)

Saturated Submerged Active

(Ka) Passive

(Kp)

Limestone fragments and fine sand 115 53 33 0.29 3.39

Limestone with fine sand 128 65 38 0.24 4.20

GENERAL INFORMATION

Our client for this geotechnical evaluation was:

Florida Keys Electric Cooperative

91630 Overseas Highway

Tavernier, Florida 33037

The contents of this report are for the exclusive use of the client and the client’s design team for this specific project exclusively. Information conveyed in this report shall not be used or relied upon by other parties or for other projects without the expressed written consent of Nutting

Engineers of Florida, Inc. This report discusses geotechnical considerations for this site based upon observed conditions and our understanding of proposed construction for foundation support.

Environmental issues including (but not limited to), soil and/or groundwater contamination are beyond our scope of service for this project. As such, this report should not be used or relied upon for evaluation of environmental issues.

If conditions are encountered which are not consistent with the findings presented in this report, or if proposed construction is altered or moved from the location investigated, this office shall be notified so that the condition or change can be evaluated, and appropriate action taken.

Nutting Engineers of Florida, Inc. (NE), recommends that we be contracted to provide input to the design team and owner during the foundation design process and that we review final foundation drawings and specifications to verify that our report recommendations and design intent have been properly implemented. NE shall also perform testing and inspections during the earthwork and foundation construction as recommended in this report. If NE is not engaged to perform these services as detailed herein, the Client agrees that NE shall bear no liability for the interpretation, implementation of our report, its recommendations and/or inspection and testing services as described in this report if implemented by others.

The Geotechnical Engineer warrants that the findings, recommendations, specifications, or professional advice contained herein, have been presented after being prepared in accordance with general accepted professional practice in the field of foundation engineering, soil mechanics and engineering geology. No other warranties are implied or expressed.

We appreciate the opportunity to be of service on this project. If we can be of any further assistance, or if you need additional information, please contact us at your convenience.

Sincerely, NUTTING ENGINEERS OF FLORIDA, INC.

Colin T. Henderson, P.E. #96283

Project Engineer

Richard C. Wohlfarth, P.E.

Director of Engineering

Attachments: Boring Location Plan

Test Boring Logs

Limitations of Liability

Soil Classification Criteria

B-1

NUTTING

ENGINEERS

OF FLORIDA, INC.

ESTABLISHED 1967

FIG. 1

APPROXIMATE

TEST LOCATION

PLAN

Florida Keys Electric Cooperative

Proposed Storage Structure

91630 Overseas Highway

Tavernier, Florida 33070

PROJECT NO. 2327.3

GEOTECHNICAL EXPLORATION

— Not to Scale —

- LEGEND -

TEST BORING LOCATION

19-27-19-8

8-9-11-6

7-29-21-36

50/5"

18-50/5"

12-20-18-24

20-16-14-26

SS

SS

SS

SS

SS

SS

SS

Lt. brown LIMESTONE FRAGMENTS with fine SAND

Lt. brown and gray LIMESTONE FRAGMENTS with fine SAND, trace peat

Lt. brown LIMESTONE with fine SAND

Bottom of hole at 20.0 feet.

SURFACE ELEVATION REFERENCE Existing ground surfaceDATE STARTED 12/9/25 COMPLETED 12/9/25

LOGGED BY Dancor CHECKED BY C. Henderson AT TIME OF DRILLING 2.5 ft

GROUND WATER LEVELS:DRILLING METHOD Standard Penetration Boring

APPROXIMATE LOCATION OF BORING As located on the approximate test location plan

D E

P T

H (f t)

G R

A P

H

IC

LO

G

N -V al u e

Blows

S A

M P

L E

T Y

P E

N U

M B

E R

FINES CONTENT (%)

20 40 60 80

SPT N VALUE

10 20 30 40

MATERIAL DESCRIPTION

20 40 60 80

PL LLMC

BORING NUMBER B-1

CLIENT Florida Keys Electric Cooperative

PROJECT LOCATION 91630 Overseas Highway, Tavernier, FL 33070

PROJECT NUMBER 2327.3

PROJECT NAME Proposed Storage Structure

T E

S T

N U

T T

IN

G

B O

R E

H O

LE

-2

7.

F

LO

R

ID

A K

E Y

S E

LE

C

T R

IC

C

O O

P E

R A

T

IV

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F

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ID

A K

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S E

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T R

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/1 1/

Nutting Engineers of Florida 9851 NW 58th St., Suite 113 Miami, Florida 33178 Telephone: (305) 557-3083 Fax: (561) 737-0075

100+

100+

LIMITATIONS OF LIABLILITY

WARRANTY

We warranty that the services performed by Nutting Engineers of Florida, Inc. are conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the profession in our area currently practicing under similar conditions at the time our services were performed. No other warranties, expressed or implied, are made. While the services of Nutting Engineers of Florida, Inc. are a valuable and integral part of the design and construction teams, we do not warrant, guarantee or insure the quality, completeness, or satisfactory performance of designs, construction plans, specifications we have not prepared, nor the ultimate performance of building site materials or assembly/construction.

SUBSURFACE EXPLORATION

Subsurface exploration is normally accomplished by test borings; test pits are sometimes employed. The method of determining the boring location and the surface elevation at the boring is noted in the report. This information is represented in the soil boring logs and/or a drawing. The location and elevation of the borings should be considered accurate only to the degree inherent with the method used and may be approximate.

The soil boring log includes sampling information, description of the materials recovered, approximate depths of boundaries between soil and rock strata as encountered and immediate depth to water data. The log represents conditions recorded specifically at the location where and when the boring was made. Site conditions may vary through time as will subsurface conditions. The boundaries between different soil strata as encountered are indicated at specific depths; however, these depths are in fact approximate and dependent upon the frequency of sampling, nature and consistency of the respective strata. Substantial variation between soil borings may commonly exist in subsurface conditions. Water level readings are made at the time and under conditions stated on the boring logs. Water levels change with time, precipitation, canal level, local well drawdown and other factors. Water level data provided on soil boring logs shall not be relied upon for groundwater based design or construction considerations.

LABORATORY AND FIELD TESTS

Tests are performed in general accordance with specific ASTM Standards unless otherwise indicated. All criteria included in a given ASTM Standard are not always required and performed. Each test boring report indicates the measurements and data developed at each specific test location.

ANALYSIS AND RECOMMENDATIONS

The geotechnical report is prepared primarily to aid in the design of site work and structural foundations. Although the information in the report is expected to be sufficient for these purposes, it shall not be utilized to determine the cost of construction nor to stand alone as a construction specification. Contractors shall verify subsurface conditions as may be appropriate prior to undertaking subsurface work.

Report recommendations are based primarily on data from test borings made at the locations shown on the test boring reports. Soil variations commonly exist between boring locations. Such variations may not become evident until construction. Test pits sometimes provide valuable supplemental information that derived from soil borings. If variations are then noted, the geotechnical engineer shall be contacted in writing immediately so that field conditions can be examined and recommendations revised if necessary.

The geotechnical report states our understanding as to the location, dimensions and structural features proposed for the site. Any significant changes of the site improvements or site conditions must be communicated in writing to the geotechnical engineer immediately so that the geotechnical analysis, conclusions, and recommendations can be reviewed and appropriately adjusted as necessary.

CONSTRUCTION OBSERVATION

Construction observation and testing is an important element of geotechnical services. The geotechnical engineer’s field representative (G.E.F.R.) is the “owner’s representative” observing the work of the contractor, performing tests and reporting data from such tests and observations. The geotechnical engineer’s field representative does not direct the contractor’s construction means, methods, operations or personnel. The G.E.F.R. does not interfere with the relationship between the owner and the contractor and, except as an observer, does not become a substitute owner on site. The G.E.F.R. is responsible for his/her safety, but has no responsibility for the safety of other personnel at the site. The G.E.F.R. is an important member of a team whose responsibility is to observe and test the work being done and report to the owner whether that work is being carried out in general conformance with the plans and specifications. The enclosed report may be relied upon solely by the named client.

d u

Laboratory classification criteria

SOIL AND ROCK CLASSIFICATION CRITERIA

N-VALUE

(bpf)

RELATIVE

HARDNESS ROCK CHARACTERISTICS

N> 100 Hard to v. hard Local rock formations vary in hardness from soft to very hard within short verti-cal and horizontal distances and often contain vertical solution holes of 3 to 36 inch diameter to varying depths and horizontal solution features. Rock may be brittle to split spoon impact, but more resistant to excavation.

25< N < 100 Medium hard to hard

5< N < 25 Soft to medium hard

ROCK

PARTICLE SIZE

Boulder >12 in. 0 – 5% Slight trace

Cobble 3 to 12 in. 6 – 10% Trace

Gravel 4.76 mm to 3 in. 11 – 20% Little

Sand 0.074 mm to 4.76 mm 21 – 35% Some

Silt 0.005 mm to 0.074 mm >35% And

Clay <0.005 mm

DESCRIPTION MODIFIERS

3 and 1

)(D C 4;an greater th

D

D C z u between xD

Not meeting all gradation requirements for GW

Atterberg limits below “A” line or P.I. less than 4

Atterberg limits above “A” line with P.I. greater than 7

Above “A” line with P.I.

between 4 and 7 are border-line cases requiring use of dual symbols.

Atterberg limits below “A” line or P.I. less than 4

Not meeting all gradation requirements for SW

Atterberg limits above “A” line with P.I. more than 7

Limits plotting in hatched zone with P.I. between 4 and 7 are borderline cases requiring use of dual system.

3 and 1 D

)(D C 6;an greater th

D

D C z u between xD

Typical names

Poorly graded gravels, gravel-sand mixtures, little or no fines

Silty gravels, gravel-sand-silt mixtures

Clayey gravels, gravel-sand-clay mixtures

Well-graded sands, gravelly sands, little or no fines

Poorly graded sands, gravelly sands, little or no fines

Silty sands, sand-silt mixtures

Clayey sands, sand-clay mixtures

Inorganic silts and very fine sands, rock flour, silty or clayey fine sands or clayey silts with slight plasticity

Inorganic clays of low to medium plasticity, gravelly clays, sandy, clays, silty clays, lean clays

Organic silts and organic silty clays of low plasticity

Inorganic silts, micaceous or diatoma-ceous fine sandy or silty soils, elastic silts

Inorganic clays or high plasticity, fat clays

Organic clays of medium to high plasticity, organic silts

Peat and other highly organic soils

GW

GP

GC

SW

SP

SC

ML

CL

OL

MH

OH

d u

C le a n g ra ve ls

(L itt le o r no f in es

G ra ve

(M or e th a n ha lf o f co a rs e fr a ct io n is la rg er t ha n N o.

s ie ve s iz e)

C oa rs e-g ra in ed s oi e th a n ha lf o f m a te ria l i s la rg er t ha n N o.

s ie ve s

G ra ve ls w ith f in es

(A p p re ci a b le a m ou nt o f fi ne s) a n sa nd s (L itt le o r no f in es

Sa nd s w ith f in es

(A p p re ci a b m ou nt o f fi ne s)

Sa nd s e th a n ha lf o f co a rs e fr a ct io n is sm lle r th a n

N o.

s ie ve s

Si lts a nd c ys iq ui d li m it le ss t ha n

Si lts a nd c ys iq ui d li m it g re a te r th a n

H ig hl y or g a ni c so ils

Fi ne

-g ra in ed s oi e th a n ha lf o f m a te ria l i s sm al le r th a n

N o.

si ev e si ze

Pl a st ic ity In d ex

80 10 20 30 40 50 60 70 90 100 Liquid Limit

Plasticity Chart

OH and MH

ML and OL

CH

CL

CL-ML

“A ” L ine

CH

Well-graded gavels, gravel-sand mixtures, little or no fines

PT

D et er m in e p er ce nt a g es o f sa nd a nd g ra ve l f ro m g ra in -s iz e cu rv e.

ep en d in g o n p er ce nt a g e of f in es fr a ct io n sm a lle r th a n

N o.

s ie ve s iz

e) , c oa rs e-g ra in ed s oi ls a re c la ss if ie d a s fo llo w s:

Le ss t ha n fi ve p er ce nt

..G

W , G

P, S

W , S

P M or e th a n p er ce nt

G

M , G

C , S

M , S t o p er ce nt

..B or de rl in e ca se s re q ui ri ng d ua l s ys te m s*

SAND/SILT

N-VALUE

(bpf)

RELATIVE

DENSITY

N-VALUE

(bpf)

UNCONFINED COMP.

STRENGTH (tsf) CONSISTENCY

0 – 4 Very Loose <2 <0.25 v. Soft

5 – 10 Loose 2 – 4 0.25 – 0.50 Soft

11 – 29 Medium 5 – 8 0.50 – 1.00 Medium

30 – 49 Dense 9 – 15 1.00 – 2.00 Stiff

>50 Very dense 16 – 30 2.00 – 4.00 v. Stiff

100 Refusal >30 >4.00 Hard

CLAY/SILTY CLAY

Group Symbols Major Divisions

GW*

SM*

2025-12-18T09:10:40-0500
Colin Thomas Henderson -- Nutting Engineers of Florida
2025-12-18T09:10:13-0500
Colin Thomas Henderson -- Nutting Engineers of Florida

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