HomeMy WebLinkAboutSW4240903_Soils/Geotechnical Report_20241114 CES$
Land Development Services
September 30, 2013
Mr. Brad Queener
Bradley Development
P.O. Box 526
Aynor, South Carolina 29511
Reference: Geotechnical Engineering Evaluation
Villas at Hickory Tree
Hickory Tree Road
Davidson County, North Carolina
CESI Project Number 130915.000
Mr. Queener:
CESI has performed a geotechnical engineering test pit evaluation in accordance with our Proposal
P130904 dated September 4, 2013.
On September 10, 2013, CESI's Geotechnical Engineer, Edward S. Cummings III, PE observed 26
test pits excavated according to the attached Test Location Plan. Two supplemental soil test borings
were performed on September 11, 2013, in opposing ends of the proposed structure for the seismic
site classification and preliminary soil bearing. The test pits and soil test borings were performed to
evaluate subsurface soil conditions in order to determine the presence of topsoil, unsuitable soils and
shallow rock.
FINDINGS
The site is bordered on the north by Hickory Tree Road, on the northeast by a single family residence
and a pre-engineered steel building, on the east by Hay Road, on the south by a residential
subdivision and a vacant site on the west.
Test pits were excavated by a CAT 315 CL track hoe at the locations shown on the enclosed Test Pit
Location Plan. Soil strata in each test pit was observed, identified and recorded by our geotechnical
engineer.
Two soil test borings, marked B-1 through B-2, were located by CESI's geotechnical engineer in
opposing ends of the subject building. The locations of the test borings are presented on the
"Test Location Plan" included in the Appendix. The test borings were advanced with an ATV
mounted CME 550X drill rig to a depth of 30.0 feet below the ground surface using continuous-
flight, hollow-stem augers. Standard penetration tests were performed at 2.5-foot increments in
the upper 10 feet and at 5-foot intervals thereafter to the termination depths in general accordance
with ASTM D 1586. Standard penetration test data was used to estimate the in-situ soil strength
and compressibility. Soil samples were obtained at each test interval. The recovered soil
samples were visually classified by our geotechnical engineer.
45 Spring Street, SW P.O. Box 268 Concord, N.C. 28026-0268 704-786-5404
www.cesilds.com N.C. License Number C-0263
Topsoil was present at the test pit and boring locations. The average topsoil depth was 0.8 feet. At
the evaluated locations within the wooded area, tree roots are prevalent in the topsoil and extend into
the underlying residual soils.
Washed in or alluvial soils were not present at test locations. Even though alluvial soils were not
encountered, these soils may be present in any drainage feature crossing the site. Alluvial soils are
compressible strata that typically have never been subject to an overburden consolidation load and
are considered nonstructural. If encountered, these alluvial soils will need to be removed prior to
structural fill placement.
Weathered in place, residual soils were encountered beneath the topsoil at the surface of the test
locations. The residual soils consisted of sandy silt (ML), silt (ML) and silty sand (SM). A composite
soil sample was obtained at test pit TP-19 from 0 to 10 feet. Based on our site observations, it is
anticipated that this area will be excavated and used as structural fill in the lower portions of the site.
These soil samples were transported to our laboratory for one point Proctor testing. Results indicate
that the maximum dry density is 94.6 pounds per cubic foot with an optimum moisture of 24.4
percent. The composite soil sample moisture was 27.2%. These soils are considered light weight
and will be sensitive to moisture.
Groundwater was encountered at 4 feet in test pit TP-25 and at 29 feet at test boring B-1. The
elevation of the groundwater may vary depending upon seasonal factors such as precipitation.
RECOMMENDATIONS
Topsoil, root zones, stumps, organics, strippings, and other unsuitable materials should be
stripped to at least 5 feet plus the plan fill depth beyond the outline of the proposed structural and
pavement areas. The entire cut/fill area should be root raked in multiple directions in order to
remove the root system created by the mature trees in the forested area on the west side.
After stripping and undercutting, we recommend that the areas to provide support be carefully
evaluated for the presence of soft surficial soils by proofrolling with a 25-ton, four-wheeled, rubber-
tired roller, a loaded dumptruck, or similar approved equipment. The proofroll operation should be
carefully monitored by our Engineer. Areas that wave, rut, or deflect excessively and continue to
do so after several passes of the proofroller may need to be undercut to stiffer soils, based on site
conditions at the time of grading. The undercut areas should be backfilled in thin lifts with
approved, compacted fill materials.
Due to the presence of fine grained soils on the site, it is imperative that positive surface drainage
be maintained during grading operations to prevent water from ponding on the surface. The
surface should be rolled smooth to enhance drainage if precipitation is expected. Subgrades
damaged by construction equipment should be immediately repaired to avoid further degradation
in adjacent areas and to help prevent water ponding.
Fill Material and Placement
Recommended criteria for soil fill characteristics and compaction procedures are listed below.
The project design documents should include the following recommendations to address proper
placement and compaction of project fill materials. We do not recommend the use of highly plastic
soils with a PI greater than 25 as structural fill within the project footprint. Earthwork operations
should not begin until representative borrow soil samples are collected and tested (allow 3 to 4
days for sampling and testing).
Villas at Hickory Tree Geotechnical Engineering Evaluation September 30,2013
CESI Project Number 130915.000 Page 2
Earth Fill Materials
❑ General guidelines for project fill should control properties such as Plasticity Index (PI),
gradation, and organic content. The use of the following USCS soil types, as defined by
ASTM D 2487, should be satisfactory for use as project fill: GW, GP, GM, GC, SW, SP,
SM, SC, ML, MH (provided the PI is 25 percent or less for MH soils), or combinations
thereof.
❑ Organic content should be no greater than 5 percent by weight, and no large roots
should be allowed. Additionally, maximum particle sizes should be limited to 4 inches or
less.
Compaction Recommendations
❑ One standard Proctor compaction test and one Atterberg limits test for each soil type
used as project fill. Gradation tests may be necessary and should be performed at the
Project Geotechnical Engineer's discretion.
❑ Maximum loose lift thickness —8 inches.
❑ Compaction requirements — 95 percent of the maximum dry density to a depth of 2 feet
below subgrade, and 100 percent within the upper 2 feet as determined by the standard
Proctor compaction test.
❑ Soil moisture content at time of compaction —within plus 3 percent to minus 3 percent of
the optimum moisture content.
❑ One density test every 2,500 square feet for each lift or two tests per lift, whichever is
greater (for preliminary planning only; the test frequency should be determined by our
geotechnical engineering staff).
❑ Trench fill areas — one density test every 75 linear feet at vertical intervals of 2 feet or
less.
The construction should be monitored by our Construction Materials Testing Engineer. Our
Construction Materials Testing Engineer's (or technician) duties should include observation of
proofrolling activities, density testing of the soil backfill, density testing of the base course, field
sampling and testing of fresh concrete and laboratory compressive strength testing of the
concrete. Field observations, monitoring, and quality assurance testing during earthwork and
pavement construction are an extension of this analysis.
The building foundations should be sized for a maximum net allowable bearing pressure not to
exceed 2,500 pounds per square foot. The exploration findings indicate the building may be
supported by shallow spread footings bearing on residual soil (equal to or greater than N=8) or
newly placed structural fill soil. Our settlement analyses using Martin's Method of Schmertmann
indicate that the total settlement potential of the footings to be less than 1/2 inch and the
differential settlement potential should be less than 1/4 inch. All footings should bear at a
minimum depth of 12 inches below exterior grades for frost protection. Properly reinforced
building footings with adequate slab and wall control joints are recommended to handle differential
settlements, if they occur.
Per Table 1613.5.2 of the 2009 International Building Code (IBC) as adopted by North Carolina, a
Site Class "D" should be assigned to the site for seismic design purposes. Site specific
subsurface data was determined to the boring termination depths of 30 feet below existing grade.
Appropriate properties were estimated for the materials deeper in the subsurface profile. The
Seismic Site Class is derived from the standard penetration test data recorded during drilling.
Based on our site observations and geotechnical findings, difficult excavation due to rock should
not be encountered during grading and utility installation operations. However, for contractual
purposes, CESI recommends that Rock be defined as the following:
Villas at Hickory Tree Geotechnical Engineering Evaluation September 30,2013
CESI Project Number 130915.000 Page 3
General Mass Rock Excavation:
Any material which cannot be excavated with a single-tooth ripper drawn by a crawler tractor
having a draw bar pull rated at not less than 56,000 pounds (Caterpillar D8K or equivalent) or
excavated by a trackhoe having a bucket curling force rated at not less than 33,000 pounds
(Caterpillar 315C or equivalent).
Trench Rock Excavation:
Any material which cannot be excavated with a backhoe having a bucket curling force rated at not
less than 33,000 pounds (Caterpillar 315C or equivalent). If these rock excavation conditions are
encountered, CESI should be notified for verification and quantification. Excavation of encountered
trench rock will then require fracturing using jack hammering or blasting.
Pavement Design and Construction Considerations
Based on final site grades and soil subgrade proofroll observations, the proposed pavement areas
maybe supported on stiff residual soil and new structural fill soil.
Prevention of infiltration of water into the subgrade is essential to the successful performance of
any pavement. To prevent the subgrade from becoming saturated and reducing its support
capabilities, we recommend that the soil subgrade be graded to provide positive drainage away
from the pavement areas.
Presented in the tables below are our pavement thickness recommendations for light and heavy
duty flexible and rigid pavement sections for the proposed driveways and parking lots. The
recommended pavement thickness below consists of minimum compacted thicknesses rather
than nominal thicknesses. The aggregate base course, asphalt surface course and concrete
sections should meet the requirements of and be placed in general accordance with the
applicable sections of the latest edition of North Carolina Department of Transportation (NCDOT)
"Standard Specifications for Roads and Structures".
Light Duty Flexible Pavement Section
Recommended Recommended
Thickness Pavement Section
2 inches Asphalt Surface Course—Type S 9.5B (NCDOT Section 610)
8 inches Aggregate Base Course (ABC)—(NCDOT Section 520)
10 inches Total Recommended Section
Heavy Duty Flexible Pavement Section
Recommended Recommended
Thickness Pavement Section
1.5 inches Asphalt Surface Course—Type S 9.5B (NCDOT Section 610)
1.5 inches Asphalt Course—Type S 9.5B (NCDOT Section 610)
8 inches Aggregate Base Course (ABC)—(NCDOT Section 520)
11 inches Total Recommended Section
Villas at Hickory Tree Geotechnical Engineering Evaluation September 30,2013
CESI Project Number 130915.000 Page 4
The pavement sections are recommended under the assumption that the residual and new
structural fill subgrade soils are thoroughly proofrolled and stable immediately prior to construction
of the aggregate base course. Schedule CESI's Engineer to witness the proofroll.
Immediately prior to the installation of the asphalt surface course, aggregate subgrade should be
proofrolled under the supervision of the Engineer. The Engineering Technician's duties should
include in-place density testing of the soil backfill, in-place density testing of the base course, and
testing of the asphalt. Field observations, monitoring, and quality assurance testing during
earthwork and pavement construction are an extension of the pavement design.
FOLLOW-UP SERVICES
Field observations, monitoring, and quality assurance testing during earthwork, foundation
installation and pavement construction are an extension of the geotechnical design. As a result
we recommend the following:
• Proofroll observations of areas to receive fill soils;
• Density testing during fill soil placement;
• Density testing for utility trench backfill;
• Foundation bearing grade evaluations;
• Concrete testing of footings and slabs;
• Proofroll observations within the pavement areas prior to aggregate and asphalt
placement.
SUMMARY
Based on our site observations and findings, the site grading contractor will encounter sandy silt(ML)
silt (ML) and silty sand (SM) appropriate for the anticipated residential construction. Building pad
construction and street subgrade preparation can be accomplished with the onsite soils using
conventional construction equipment and the recommendations as outlined above.
We appreciate the opportunity to be of service to Bradley Development and we look forward to
helping you throug j oject completion. If you have any questions, please feel free to call.
ow tkakt,
Respectf w',y �Y �N1'5 ,.,0
CESI t C, S
t411- I" 73 _ -
/ i
Edward S."�` ,.o r i�@I gill i ^\ 77 Ja ds G. (Jay) Eaves III P.E.
Geotechnical - Division Manager
N.C. Registration Number 24963 N.C. Registration Number 27837 •
ATTACHED:
TEST LOCATION PLAN
RECORD OF TEST PIT EXCAVATION
KEY TO SYMBOLS
LOG OF TEST BORINGS
PROCEDURES
VAPOR BARRIER INFORMATION
Villas at Hickory Tree Geotechnical Engineering Evaluation September 30,2013
CESI Project Number 130915.000 Page 5
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1 a Test Pit Excavation
TEST LOCATION PLAN DATE: 8-29-13
CESI VILLAS AT HICKORY TREE DRAWN BY: JGE
HICKORY TREE ROAD PROJECT#: 130915.000
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�' ,�, DAVIDSON COUNTY, NORTH CAROLINA SCALE: NTS
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IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings Ill, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-1 0 1 Topsoil and Roots
1 2 RESIDUUM: Mottled yellowish brown and red fine sandy SILT (ML)
2 5.5 Mottled red and yellow fine sandy SILT (ML)
TP-2 0 0.8 Topsoil and Roots
0.8 2 RESIDUUM: Mottled red and yellow fine sandy SILT (ML)
2 5 Mottled red, yellow and gray fine sandy SILT( ML)
TP-3 0 0.5 Topsoil and Roots
0.5 1.5 RESIDUUM: Moist red slightly micaceous fine sandy SILT (ML)
1.5 5 Red, yellow and white fine sandy SILT (ML)
5 6 Olive and white fine sandy SILT (ML)
IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings III, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-4 0 0.7 Topsoil and roots
0.7 1.5 RESIDUUM: Red slightly micaceous fine sandy SILT (ML)
1.5 4.5 Light red, olive and white fine sandy SILT (ML)
4.5 7.0 Olive, white and red fine sandy SILT (ML)
TP-5 0 1 Topsoil and roots
1.0 1.5 RESIDUUM: Red and yellow fine sandy SILT (ML)
1.5 5 Yellow and red fine sandy SILT (ML)
TP-6 0 1 Topsoil and roots
1 2 RESIDUUM: Yellowish red fine sandy SILT (ML)
2 5 Yellow and red fine sandy SILT (ML)
IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings III, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-7 0 0.7 Topsoil and roots
0.7 1 RESIDUUM: Yellowish red fine sandy SILT (ML)
1 5 Red, yellow and olive fine sandy SILT (ML)
5 7 White, olive and red fine sandy SILT (ML)
TP-8 0 0.8 Topsoil and roots
0.8 1.3 RESIDUUM: Moist yellowish red and gray fine sandy SILT (ML)
1.3 5.5 Red and yellow fine sandy SILT (ML)
TP-9 0 0.7 Topsoil and roots
0.7 1 RESIDUUM: Moist reddish yellow fine sandy SILT (ML)
1 5 Mottled red and yellow fine sandy SILT (ML)
IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings Ill, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-10 0 1 Topsoil and roots
1 1.7 RESIDUUM: Moist yellowish brown fine sandy SILT (ML)
1.7 4 Red and yellow fine sandy SILT (ML)
4 5 Olive and yellow fine sandy SILT (ML)
5 6 Olive, white and red fine sandy SILT (ML)
TP-11 0 0.8 Topsoil and roots
0.8 1.4 RESIDUUM: Moist yellow and red fine sandy SILT (ML)
1.4 4 Red and yellow fine sandy SILT (ML)
4 5.5 Light yellow and red fine sandy SILT (ML)
TP-12 0 0.8 Topsoil and roots
0.8 3 RESIDUUM: Moist red slightly micaceous fine sandy SILT (ML)
3 6 Yellow, red and olive fine sandy SILT (ML)
IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings III, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-13 0 0.8 Topsoil and roots
0.8 1 RESIDUUM: Red fine sandy SILT (ML)
1 3 Yellow and red fine sandy SILT (ML)
3 6.5 Light brown, white and red fine sandy SILT (ML)
TP-14 0 0.8 Topsoil and roots
0.8 1.5 RESIDUUM: Moist yellow and red fine sandy SILT (ML)
1.5 5 Mottled red and yellow fine sandy SILT (ML)
TP-15 0 0.8 Topsoil and roots
0.8 2 RESIDUUM: Moist red fine sandy SILT (ML)
2 3 Red and yellow fine sandy SILT (ML)
3 7 Yellow, white and olive fine sandy SILT (ML)
7 9.5 Brown and white fine sandy SILT (ML)
IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings III, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-16 0 0.8 Topsoil and roots
0.8 2 RESIDUUM: Red fine sandy SILT (ML)
2 4 Yellow, red and white fine sandy SILT (ML)
4 10 Yellow and white fine sandy SILT (ML)
TP-17 0 0.7 Topsoil and roots
0.7 1 RESIDUUM: Moist yellow fine sandy SILT (ML)
1 3 Moist yellow and red SILT (ML)
3 6 Red and yellow fine sandy SILT (ML)
TP-18 0 0.8 Topsoil and roots
0.8 3 RESIDUUM: Moist red and yellow fine sandy SILT (ML)
3 7 Yellow and red fine sandy SILT (ML)
IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings III, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-19 0 0.7 Topsoil and roots
0.7 2 RESIDUUM: Moist red fine sandy SILT (ML)
2 6 Red and yellow fine sandy SILT (ML)
6 10 Yellow, red and olive fine sandy SILT (ML)
TP-20 0 0.8 Topsoil and roots
0.8 1.5 RESIDUUM: Red fine sandy SILT (ML)
1.5 4 Yellow and red fine sandy SILT (ML)
4 5 Yellow, red and white fine sandy SILT (ML)
TP-21 0 1 Topsoil and roots
1 3 RESIDUUM: Moist reddish brown fine sandy SILT (ML)
3 5.5 Gray, yellow and brown slightly micaceous fine sandy SILT (ML)
IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings III, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-22 0 0.7 Topsoil and roots
0.7 1 RESIDUUM: Yellow fine sandy SILT (ML)
1 2.5 Red and yellow fine sandy SILT (ML)
2.5 5 Yellow, brown and white fine sandy SILT (ML)
TP-23 0 0.7 Topsoil and roots
0.7 3 RESIDUUM: Yellow and red slightly micaceous fine sandy SILT (ML)
3 5 Gray, yellow and red fine sandy SILT (ML) with 1/8" rock fragments
TP-24 0 0.8 Topsoil and roots
0.8 1 RESIDUUM: Red fine sandy SILT (ML)
1 4 Yellow and red fine sandy SILT (ML)
4 5 Brown and white fine sandy SILT (ML)
IEScT RECORD OF TEST PIT EXCAVATION
PROJECT: Villas at Hickory Tree EXCAVATOR: CAT 315 CL
CLIENT: Bradley Development DATE: 9/10/13
CESI REPRESENTATIVE: Edward S. Cummings III, PE CESI JOB NO: 130915.000
TEST PIT DEPTH (ft.) DESCRIPTION EXCAVATION
NO. From To DIFFICULTY
TP-25 0 0.8 Topsoil and roots
0.8 2 RESIDUUM: Moist yellow and red fine sandy SILT (ML)
2 4 Yellow and red fine sandy SILT (ML)
4 8 Light gray and red fine sandy SILT (ML) Water at 4'
8 10 Yellow silty fine SAND (SM)
TP-26 0 0.8 Topsoil and roots
0.8 4 RESIDUUM: Moist yellow and red fine sandy SILT (ML)
4 6 Moist red and yellow fine sandy SILT (ML)
6 8 Moist gray and red slightly micaceous SILT (ML)
8 8.5 Moist yellow fine sandy SILT (ML)
8.5 11 Moist olive, yellow and white slightly micaceous fine sandy SILT (ML)
SOIL CLASSIFICATION CHART CORRELATION OF
MAJOR DIVISIONS SYMBOLS TYPICAL
GRAPH LETTER DESCRIPTIONS STANDARD PENETRATION RESISTANCE
■wo■s WITH
CLEAN ' GW WELL-GRADED
NoG ADRESRA GRAVELS, - RELATIVE DENSITY AND CONSISTENCY
GRAVEL GRAVELS ......1. FINES
AND o`?LS o`?LS
GRAVELLY I Qo Qo POORLY-GRADED GRAVELS,
SOILS (LITTLE OR NO FINES))o D�o DC GP GRAVEL-SAND MIXTURES,LITTLE
DO n/Oe O O OR NO FINES
COARSE 0 I U
GRAINED GRAVELS WITH j(3 �O''C GM SILTY GRAVELS,GRAVEL-SAND- Sand and Gravel
SOILS MORE THAN 50% FINES lb
SILT MIXTURES
OF COARSE DO o Q
FRACTION !r Standard Penetration Resistance Approximate
RETAINED ON NO. AVBlowSper Foot Relative Density
AMOUNT OF FINES) f�� � " 0-4 Very Loose
- '� s 5-10 Loose
CLEAN SANDS G WELL-GRADED SANDS,GRAVELLY 11-20 Firm
MORE THAN 50% SAND I SW SANDS,LITTLE OR NO FINES 21-30 Very Firm
OF MATERIAL IS AND
LARGER THAN SANDY `" 31-50 Dense
NO.200 SIEVE SOILS POORLY-GRADED SANDS,
SIZE (LITTLE OR NO FINES)::.:::::.:::.:::::::.. SP GRAVELLY SAND,LITTLE OR NO Over 50 Very Dense
FINES
SANDS WITH SILTY SANDS,SAND-SILT
MORE THAN 50% FINES SM MIXTURES Silt and Clay
OF COARSE
FRACTION
PASSING ON NO. Standard Penetration Resistance Approximate
4 SIEVE AMOUNT OF FINES) :.; SC MIXTURES CLAYEY SANDS,SAND-CLAY Blows per Foot Consistency
0-1 Very Soft
INORGANIC SILTS AND VERY FINE 2-4 Soft
ML R CLAYEY FIINEK FLOUR, OR SANDS OR CLAYEY 5-8 Firm
SILTS WITH SLIGHT PLASTICITY 9-15 Stiff
SILTS INORGANIC CLAYS OF LOW TO
FINE AND LIQUID LIMIT `L MEDIUM PLASTICITY,GRAVELLY £t-! 0
GRAINED CLAYS SANCLAYS ] Very Hard
___ OL ORGANIC SILTS AND ORGANIC
— — — SILTY CLAYS OF LOW PLASTICITY
MORE THAN 50% INORGANIC SILTS,MICACEOUS OR
OF MATERIAL IS MH DIATOMACEOUS FINE SAND OR
SMALLER THAN SILTY SOILS CES$
NO.200 SIEVE
SIZE SILTS
AND LIQUID LIMIT CH INORGANIC CLAYS OF HIGH
CLAYS GREATER THAN 50 l� PLASTICITY
OH ORGANIC CLAYS OF MEDIUM TO
,,.., HIGH PLASTICITY,ORGANIC SILTS
Key to Symbols and Descriptions
HIGHLY ORGANIC SOILS ,, ,,„ ���' ,,I' = PT PEAT,HUMUS,SWAMP SOILS WITH
HIGH ORGANIC CONTENTS
NOTE DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS
Log of Test Boring No. B-1 Page 1 of 1
CEOProject : Villas at Hickory Tree Date Drilled : 09/11/2013
Location : Davidson County,NC Project No. 130915.000
Drilling Method: Hollow Stem Augers Rig Type: CME 550X Surface Elevation: Not Determined ft. Cave-in Depth :* 24.7 ft.
Initial GWL: V 29.0 ft. Delayed GWL: ft.
Boring Diameter: 6" Hammer: Automatic
Northing: ft. Easting: ft.
SAMPLE TYPE ll DISTURBED ® SPT SAMPLE ■ SHELBY TUBE 0 NO RECOVERY Q CORE
SAMPLES
D MATERIAL CLASSIFICATION PL(%) NMC(%) LL(%)
F AND REMARKS L T BLOWS O 0 0
E T I G Y PER
FINES(%)
V H T W P 6 IN. • SPT N-Value(bpf)
(ft) (ft) H L E 1 0 20 30 40 50 70 90
— 0 —
Topsoil
RESIDUUM: Very stiff red fine sandy SILT u 3-7-11
(ML) / \
- - Very stiff red and yellow slightly micaceous a 5-8-12
— 5 — fine sandy SILT (ML) / \
Stiff yellow and red slightly micaceous fine u 3-6-6
sandy SILT (ML)
- - Stiff mottled brown and white slightly 3-4-5
—10— micaceous fine sandy SILT (ML)with 1/8" rock
- - fragments
•
•
- - Stiff mottled brown, white and yellow slightly • X 3-4-5
—15— micaceous fine sandy SILT (ML) •
•
•
- - Stiff moist mottled brown, white and black u 3-4-6
—20— slightly micaceous fine sandy SILT(ML)with / \
- 1/8" rock fragments
o -
U'
1a X 3-5-5
W -25—
z
•
- -
0 •
U -
o - - Firm very moist light brown and white fine to • - u 3-3-4
—30—coarse sandy SILT (ML)with 1/8"to 1/4" rock / \
_ _ fragments
- - Boring terminated at 30 feet
o -
m
z
0
w Key to Abbreviations
GWL-Groundwater Level PL-Plastic Limit NMC-Natural Moisture Content
o LITH-Lithologic Symbol LL-Liquid Limit SPT-Standard Penetration Test
Log of Test Boring No. B-2 Page 1 of 1
CEOProject : Villas at Hickory Tree Date Drilled : 09/11/2013
Location : Davidson County,NC Project No. 130915.000
Drilling Method: Hollow Stem Augers Rig Type: CME 550X Surface Elevation: Not Determined ft. Cave-in Depth :* 26.9 ft.
Initial GWL: Not Encountered ft. Delayed GWL: ft.
Boring Diameter: 6" Hammer: Automatic
Northing: ft. Easting: ft.
SAMPLE TYPE ll DISTURBED ® SPT SAMPLE ■ SHELBY TUBE 0 NO RECOVERY Q CORE
SAMPLES
D MATERIAL CLASSIFICATION PL(%) NMC(%) LL(%)
F AND REMARKS L T BLOWS O 0 0
E T I G Y PER
FINES(%)
V H T W P 6 IN. • SPT N-Value(bpf)
(ft) (ft) H L E 1 0 20 30 40 50 70 90
— 0 •
—
To soil
RESIDUUM: Stiff red and yellow fine sandy X 3-4-6
SILT (ML)- -
•
Stiff mottled red, yellow and black fine sandy a 4-6-7
11)1
— 5 — SILT (ML) / \
Stiff yellow and red slightly micaceous fine u 3-4-6
sandy SILT (ML)
- - Firm mottled white, gray and yellow slightly 3-3-5
—10— micaceous fine sandy SILT (ML)
•
- - Stiff mottled brown, gray and white slightly / \ 4-4-5
—15— micaceous fine sandy SILT (ML) / \
•
•
- - Firm to stiff moist mottled gray, white and red T u 3-3-4
—20— slightly micaceous fine sandy SILT(ML) / \
M
O
M
0
•
•
•
F
o - -
•
\ /z X 2-4-6
W —25—
z
I
° - - Firm mottled brown and white micaceous fine • u
—30-sandy SILT (ML) / \ 2-3-3
o - - Boring terminated at 30 feet
0 - -
z
0
Q1
0 - -
z
0
wKey to Abbreviations
GWL-Groundwater Level PL-Plastic Limit NMC-Natural Moisture Content
o LITH-Lithologic Symbol LL-Liquid Limit SPT-Standard Penetration Test
FIELD PROCEDURE
SOIL TEST BORINGS
ASTM D-1586
The borings were made by advancing 5 inch diameter hollow stem augers. At regular intervals, soil
samples were obtained through the hollow stem augers with a standard 1.4-inch I.D., 2.0-inch O.D.,
split-tube sampler.
The sampler was initially seated 6 inches to penetrate any loose cuttings; then driven an additional foot
with blows of a 140-pound hammer falling 30 inches. The number of hammer blows required to drive
the sampler the final foot was recorded and is designated as the standard penetration resistance.
Penetration resistance, when properly evaluated, is an index to the soil's strength and density.
The samples were classified in the field by the driller as they were obtained. Representative portions of
each soil sample were then sealed in labeled glass jars and transported to our laboratory. The samples
were examined by a graduate geotechnical engineer or engineering geologist to check visually the field
classification. All boring data, including sampling intervals, penetration resistances, soil classifications,
and groundwater level are shown on the attached Test Boring Records.
An ACI warning:
Vapor Retarder Location
ACI committee 302, "Guide for Concrete Floor and Slab Construction: (ACI 302, 1 R-96) states in
section 4.1.5 that "if a vapor barrier or retarder is required due to local conditions, these products
should be placed under a minimum of 4 in. (100 mm) of trimable, compactible, granular fill (not
sand)." The Moisture Task Group of ACI Committees 302 & 360 has found examples where this
approach has directly contributed to floor covering problems and failures.
As a result of reviewing the details of problem installations, it became clear that the fill course
above the vapor retarder had taken on water from rain, wet-curing, wet-grinding or cutting, and
cleaning. Unable to drain, the wet or saturated fill provides and additional source of water that
contributes to moisture-vapor emission rates from the slab well in excess of the 3 to 5 lb/ 1000sf
/24 hr. recommendation of the floor covering manufacturers.
As a result of these experiences, and the difficulties involved with adequately protecting the fill
course from water during the construction process, caution is advised as to the use of the granular
fill layer when moisture-sensitive finishes are to be applied to the slab surface.
The task group believes that when the use of a vapor retarder or barrier is required, the decision
whether to locate the material in direct contact with the slab or beneath a layer of granular fill
should be made on a case-by-case basis.
Each proposed installation should be independently evaluated as to the moisture sensitivity of
subsequent floor finishes, anticipated project conditions, and the potential effects of slab curling
and cracking.
The following chart can be used to assist in the evaluation process. The anticipated benefits and
risks associated with the specified location of the vapor retarder should be reviewed with all
appropriate parties prior construction.
Flow Chart for Location of Vapor Retarder/Barrier
Does the project have a vapor-sensitive No
covering or a humidity-controlled area?
1
Yes Fig. 1
Vapor retarder/barrier is required
1 1
Slabs with vapor- Slabs in humidity-controlled areas
sensitive coverings
1
Will the slabs be placed with
Fig. 2 waterproof roof membrane in place?*
No Yes
1
Fig. 2 Fig. 3
" / V//4/� //-4 ///
Dry, granular material o Dry, granular material o Dry, granular material
Figure 1 Figure 2 Figure 3
*If granular material is subject to future moisture infiltration, use Fig. 2