HomeMy WebLinkAboutSubsoil Study for Foundation Design 01.29.2021lGrtiiffilfi*i'ff#ir':r'i;**'
An Employcc Owncd Compony
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email : kaglenwood@kumarusa.com
www.kumarusa. com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
SUBSOIL STUDY
FOR FOUNDATION DESIGN
PROPOSED RESIDENCE
LOT 261,IRONBRIDGE
RIVER VISTA
GARFIELD COUNTY, COLORADO
PROJECT NO. 20-7-788
JANUARY 29,2021
PREPARED FOR
scrB, LLc
ATTN: LUKE GOSDA
0115 BOOMERANG ROAD, SUrTE 52018
ASPEN, COLORADO 81611
(luke.gosda@sunrircco.com)
TABLE OF CONTENTS
PURPOSE AND SCOPE OF STUDY
BACKGROUND INFORMATION
PROPOSED CONSTRUCTION ...
SITE CONDITIONS..
FIELD EXPLORATION..
SUBSURFACE CONDITIONS
FOLINDATION BEARING CONDITIONS
DESIGN RECOMMENDATIONS ...............
FOLINDATIONS
FOLTNDATION AND RETAINING V/ALLS ....
NONSTRUCTURAL FLOOR SLABS
UNDERDRAIN SYSTEM .............
SITE GRADING.......
4-
4-
5-
6-
7-
7-
1
I
1
.,
SUBSIDENCE POTENTIAL........ .,.- 2 -
-3-
.......- 8 -
-3-
a
8
SURFACE DRAINAGE.........
LIMITATIONS
FIGURE 1 - LOCATION OF EXPLORATORY BORING
FIGURE 2 - LOG OF EXPLORATORY BORING
FIGURE 3 - SWELL-CONSOLIDATION TEST RESULTS
FIGURES 4 AND 5 - GRADATION TEST RESULTS
TABLE 1- SUMMARY OF LABORATORY TEST RESULTS
Kumar & Associates, lnc. o Project No. 20-7-788
PURPOSE AND SCOPE OF STUDY
This report presents the results of a subsoil study for a proposed residence to be located on
Lot26l,Ironbridge, River Vista, Garfield County, Colorado. The project site is shown on
Figure 1. The purpose of the study was to develop recommendations for the foundation design.
The study was conducted in accordance with our agreement for geotechnical engineering
services to SCIB, LLC dated December 31,2020.
An exploratory boring was drilled to obtain information on the subsurface conditions. Samples
of the subsoils obtained during the field exploration were tested in the laboratory to determine
their classification, compressibility or swell and other engineering characteristics. The results of
the field exploration and laboratory testing were analyzedto develop recommendations for
foundation types, depths and allowable pressures for the proposed building foundation. This
report summarizes the data obtained during this study and presents our conclusions, design
recommendations and other geotechnical engineering considerations based on the proposed
construction and the subsurface conditions encountered.
BACKGROUND INFORMATION
The proposed residence is located in the existing Ironbridge development. Hepworth-Pawlak
Geotechnical, Inc. (now Kumar & Associates) previously conducted subsurface exploration and
geotechnical evaluation for the development of Villas North and Villas South parcels, Job No.
105 115-6, report dated September 14,2005, and performed observation and testing services
during the infrastructure construction, Job No. 106 0367, between April 2006 and April 2007.
The information provided in these previous reports has been considered in the current study of
Lot26I.
PROPOSED CONSTRUCTION
At the time of our study, design plans for the residence had not been developed. The residence
will likely be a one or two-story, wood-frame structure with structural slab foundation and no
basement or crawlspace. Grading for the structure is assumed to be relatively minor with cut
depths between about 3 to 4 feet. We assume relatively light foundation loadings, typical of the
proposed type of construction.
Kumar & Associates, lnc. @ Project No. 20-7-788
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If building loadings, location or grading plans change significantly from those described above,
we should be notified to re-evaluate the recommendations contained in this report.
SITE CONDITIONS
The subject site was vacant at the time of our field exploration. The lot is located in the
northeastern part of the Villas South Parcel. The natural terrain prior to development in 2006
sloped down to the east at about 5o/o grade. The subdivision area was elevated by filling on the
order of 18 feet above the original ground surface to create a relatively flat building site off River
Vista. Vegetation consists of grass and weeds with scattered sage brush.
SUBSIDENCE POTENTIAL
Eagle Valley Evaporite underlies the project area which is known to be associated with sinkholes
and localized ground subsidence in the Roaring Fork Valley. A sinkhole opened in the cart
storage parking lot located east of the Pro Shop and north of the Villas South parcel in January
2005. Irregular surface features were not observed in the Villas South parcel that could indicate
an unusual risk of future ground subsidence and localized variable depths of the debris fan soils
were generally not encountered by the previous September 14,2005 geotechnical study. The
current subsurface exploration performed in the area of the proposed residence on Lot 261 did
not encounter voids. In our opinion, the risk of future ground subsidence on Lot 261 throughout
the service life of the proposed residence is low and similar to other areas of the Roaring Fork
Valley where there have not been indications of ground subsidence.
FIELD EXPLORATION
The field exploration for the project was conducted on January 12,2021. One exploratory
boring was drilled at the location shown on Figure 1 to evaluate the subsurface conditions. The
boring was advanced with 4 inch diameter continuous flight augers powered by a truck-mounted
CME-458 drill rig. The boring was logged by a representative of Kumar & Associates, Inc.
Samples of the subsoils were taken with l% inch and 2 inch LD. spoon samplers. The samplers
were driven into the subsoils at various depths with blows from a 140 pound hammer falling 30
inches. This test is similar to the standard penetration test described by ASTM Method D-1586.
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The penetration resistance values are an indication of the relative density or consistency of the
subsoils. Depths at which the samples were taken and the penetration resistance values are
shown on the Log of Exploratory Boring, Figure 2. The samples were returned to our laboratory
for review by the project engineer and testing.
SUBSURFACE CONDITIONS
A graphic log of the subsurface conditions encountered at the site is shown on Figure 2. The
subsoils consist of about 1 foot of topsoil overlying compacted fill soils to 18 feet deep overlying
medium dense/stiff, sand and silt soils with gravel (alluvial fan deposits) underlain by dense,
sandy gravel with cobbles (river gravel alluvium) at a depth of about 38 feet to the maximum
drilled depth of 46 feet. The fill materials were mainly placed in2006 and consist of relatively
dense, mixed silt, sand and gravel.
Laboratory testing performed on samples obtained from the boring included natural moisture
content and density and gradation analyses. Results of swell-consolidation testing performed on
a relatively undisturbed drive sample of the sand and silt soil, presented on Figure 3, indicate low
to moderate compressibility under conditions of loading and wetting. Results of gradation
analyses performed on small diameter drive samples (minus llz-inch fraction) of the coarse
granular subsoils are shown on Figures 4 and 5. The laboratory testing is summarized in
Table 1.
No free water was encountered in the boring at the time of drilling and the subsoils were slightly
moist.
FOUNDATION BEARING CONDITIONS
The upper 18 feet of soils encountered in the boring consist of fill placed mainly in2006 as part
of the subdivision development. The field penetration tests and laboratory tests performed for
the study, and review of the field density tests performed during the fill construction indicate the
structural fill was placed and compacted to the project specified minimum 95o/o of standard
Proctor density. Alluvial fan soils which tend to collapse (settle under constant load) when
wetted were encountered below the fiIl. The amount of settlement will depend on the thickness
of the compressible soils due to potential collapse when wetted, and the future compression of
Kumar & Associates, lnc. @ Project No. 20-7-788
4
the wetted soils following construction. Relatively deep structural fill as encountered will also
have some potential for long-term settlement but should be significantly less than the alluvial fan
deposits. Proper grading, drainage and compaction as presented in the Surface Drainage section
will help to keep the subsoils dry and reduce the settlement risks. A heavily reinforced structural
slab or post-tensioned slab foundation designed for significant differential settlements is
recommended for the building support. As an alternative, a deep foundation that extends down
into the underlying dense, river gravel alluvium could be used to reduce the building settlement
risk.
DESIGN RECOMMENDATIONS
FOTINDATIONS
Considering the subsurface conditions encountered in the exploratory boring and the nature of
the proposed construction, we recommend the building be founded with a heavily reinforced
structural slab or post-tensioned slab foundation bearing on at least 18 feet of the existing
compacted structural fill. If a deep foundation system is considered for building support, we
should be contacted for additional recommendations.
The design and construction criteria presented below should be observed for a heavily reinforced
structural slab or post-tensioned slab foundation system.
1) A heavily reinforced structural slab or post-tensioned slab placed on compacted
structural f,rll should be designed for an allowable bearing pressure of 1,500 psf.
The post-tensioned slab placed on structural fill should be designed for a wetted
distance of 10 feet or at least half of the slab width, whichever is greater.
Settlement of foundation is estimated to be about I to I% inches based on the
long-term compressibility of the fill. Additional settlement of about I to 2 inches
is estimated if the underlying debris fan soils were to become wet. Settlement
from the deep wetting would tend to be uniform across the buildingarea and the
settlement potential of the fill section should control the design.
2) The thickened sections of the slab for support of concentrated loads should have a
minimum width of 20 inches.
3) The perimeter turn-down section of the slab should be provided with adequate soil
cover above their bearing elevation for frost protection. Placement of foundations
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4)
at least 36 incbesåelow exterior grade is typically used in this area. If a frost-
protected foundation is used, the perimeter turn-down section should have at least
18 inches of soil cover.
The foundation should be constructed in a "box-like" configuration rather than
with irregular extensions which can settle differentially to the main building area.
The foundation walls, where provided, should be heavily reinforced top and
bottom to span local anomalies such as by assuming an unsupported length of at
least 14 feet. Foundation walls acting as retaining structures, if any, should also
be designed to resist laterul earth pressures as discussed in the "Foundation and
Retaining Walls" section of this report.
The root zone and any loose or disturbed soils should be removed. Additional
structural fill placed below the slab should be compacted to at least 98% of the
maximum standard Proctor density within 2 percentage points of the optimum
moisture content.
A representative of the geotechnical engineer should evaluate the compaction of
the fill materials and observe all footing excavations prior to concrete placement
to evaluate bearing conditions.
FOUNDATION AND RETAINING WALLS
Foundation walls and retaining structures (if any) which are laterally supported and can be
expected to undergo only a slight amount of deflection should be designed for a lateral earth
pressure computed on the basis of an equivalent fluid unit weight of at least 50 pcf for backfill
consisting of the on-site soils. Cantilevered retaining structures which are separate from the
residence and can be expected to deflect suffrciently to mobilize the full active earth pressure
condition should be designed for a lateral earth pressure computed on the basis of an equivalent
fluid unit weight of at least 40 pcf for backfill consisting of the on-site soils.
All foundation and retaining structures should be designed for appropriate hydrostatic and
surcharge pressures such as adjacent footings, traffr,c, construction materials and equipment. The
pressures recommended above assume drained conditions behind the walls and a horizontal
backhll surface. The buildup of water behind a wall or an upward sloping backltll surface will
increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain
should be provided to prevent hydrostatic pressure buildup behind walls.
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6)
Kumar & Associates, lnc. @ Project No. 20-7-788
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Backfill should be placed in uniform lifts and compacted to at least 90% of the maxrmum
standard Proctor density at a moisture content near optimum. Backfill placed in pavement and
walkway areas should be compacted to at least 95%:o of the maximum standard Proctor density.
Care should be taken not to overcompact the backfill or use large equipment near the wall, since
this could cause excessive lateral pressure on the wall. Some settlement of deep foundation wall
backfill should be expected, even if the material is placed correctly, and could result in distress to
facilities constructed on the backfill.
The lateral resistance of foundation or retaining wall footings will be a combination of the
sliding resistance of the footing on the foundation materials and passive earth pressure against
the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated
based on a coefficient of friction of 0.35. Passive pressure of compacted backfill against the
sides of the footings can be calculated using an equivalent fluid unit weight of 325 pcf. The
coefficient of friction and passive pressure values recommended above assume ultimate soil
strength. Suitable factors of safety should be included in the design to limit the strain which will
occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against
the sides of the footings to resist lateral loads should be compacted to at least 95Yo of the
maximum standard Proctor density at a moisture content near optimum.
NONSTRUCTURAL FLOOR SLABS
Compacted structural fill can be used to support lightly loaded slab-on-grade construction
separate from the building foundation. The f,rll soils can be compressible when wetted and can
result in some post-construction settlement. To reduce the effects of some differential
movement, nonstructural floor slabs should be separated from buildings to allow unrestrained
vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage
cracking. The requirements for joint spacing and slab reinforcement should be established by the
designer based on experience and the intended slab use. A minimum 4 inch layer of relatively
well-graded sand and gravel, such as road base, should be placed beneath slabs as subgrade
support. This material should consist of minus 2-inch aggregate with at least 50% retained on
the No. 4 sieve and less than l2o/o passing the No. 200 sieve.
Kumar & Associates, lnc. @ Project No. 20-7-788
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All fill materials for support of floor slabs should be compacted to at least 95o/o of maximum
standard Proctor density at a moisture content near optimum. Required fill can consist of the on-
site granular soils devoid of vegetation, topsoil and oversized rock.
UNDERDRAIN SYSTEM
It is our understanding the f,rnished floor elevation at the lowest level is at or above the
surrounding grade. Therefore, a foundation drain system is not required. It has been our
experience in the areathat local perched groundwater can develop during times of heavy
precipitation or ssasonal runoff. Frozen ground during spring runoff can create a perched
condition. We recommend below-grade construction, such as retaining walls, be protected from
wetting and hydrostatic pressure buildup by an underdrain and wall drain system.
If the f,rnished floor elevation of the proposed structure has a floor level below the surrounding
grade, we should be contacted to provide recommendations for an underdrain system. All earth
retaining structures should be properly drained.
SITE GRADING
Extensive grading was performed as part of the existing Villas South development. Additional
placement and compaction of the debris fan soils could be needed to elevate the site to design
grades and reduce the risk of excessive differential settlements and building distress. In addition,
the water and sewer pipe joints should be mechanically restrained to reduce the risk ofjoint
separation in the event of excessive differential settlement. Additional structural fill placed
below foundation bearing level should be compacted to at least 98%o of the maximum standard
Proctor density within 2Yo of optimum moisture content. Prior to f,rll placement, the subgrade
should be carefully prepared by removing any vegetation and organic soils and compacting to at
least95%o of the maximum standard Proctor density atnear optimum moisture content. The fill
should be benched into slopes that exceed 20Yo grade.
Permanent unretained cut and fill slopes should be graded at?horizontal to 1 vertical or flatter
and protected against erosion by revegetation or other means. This off,rce should review site
grading plans for the project prior to construction.
Kumar & Associates, lnc. @ Project No. 20-7-788
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SURFACE DRAINAGE
Precautions to prevent wetting of the bearing soils, such as proper backfill construction, positive
backhll slopes, restricting landscape irrigation and use of roof gutters, need to be taken to help
limit settlement and building distress. The following drainage precautions should be observed
during construction and maintained at all times after the residence has been completed:
1) Inundation of the building structural slab foundation excavations should be
avoided during construction.
2) Exterior backfill should be adjusted to near optimum moisture and compacted to
at least 95o/o of the maximum standard Proctor density in pavement and
nonstructural slab areas and to at least 90Yo of the maximum standard Proctor
density in landscape areas.
3) The ground surface surrounding the exterior of the building should be sloped to
drain away from the foundation in all directions. We recommend a minimum
slope of 6 inches in the first 5 feet in unpaved areas and a minimum slope of
3 inches in the first 10 feet in paved areas. Graded swales should have a
minimum slope of 3%.
4) Roof downspouts and drains should discharge at least 5 feet beyond the
foundation and preferably into a subsurface solid drainpipe.
5) Landscaping which requires regular heavy irrigation should be located at least
10 feet from foundation walls. Consideration should be given to use of xeriscape
to reduce the potential for wetting of soils below the building caused by inigation
LIMITATIONS
This study has been conducted in accordance with generally accepted geotechnical engineering
principles and practices in this area at this time. 'We make no warranty either express or implied.
The conclusions and recommendations submitted in this report are based upon the data obtained
from the exploratory boring drilled at the location indicated on Figure 1, the proposed type of
construction and our experience in the area. Our services do not include determining the
presence, prevention or possibility of mold or other biological contaminants (MOBC) developing
in the future. If the client is concerned about MOBC, then a professional in this special field of
practice should be consulted. Our findings include interpolation and extrapolation of the
Kumar & Associates, lnc. o Project No. 20-7-788
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subsurface conditions identified at the exploratory boring and variations in the subsurface
conditions may not become evident until excavation is performed. If conditions encountered
during construction appear different from those described in this report, we should be notified so
that re-evaluation of the recommendations may be made.
This report has been prepared for the exclusive use by our client for design purposes. We are not
responsible for technical interpretations by others of our information. As the project evolves, we
should provide continued consultation and field services during construction to review and
monitor the implementation of our recommendations, and to verifu that the recommendations
have been appropriately interpreted. Significant design changes may require additional analysis
or modifications to the recommendations presented herein. We recommend on-site observation
of excavations and foundation bearing strata and testing of structural fill by a representative of
the geotechnical engineer.
Respectfully Submitted,
Kumar & Associates, Inc.
!r/k
Jámes H. Parsons, E.I.
Reviewed by:
Steven L. Pawlak, P
JHPlkac
ø,162?,,
Kumar & Associates, lnc. cr Project No. 20.7.788
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APPROXIMATE SCALE_FEET
Kumar & Associates20-7 -788 LOCATION OF EXPLORATORY BORINU Fig.1
È
BORING 1
EL. 5970.5'LEGEND
0 TOPSOIL, CLAYEY SAND AND SILT, ROOTS AND ORGANICS, FIRM,
MOIST, BROWN.
68/ 12
FILL: MIXED SAND, GRAVEL AND SILT, SLIGHTLY CLAYEY, DENSE,
SLIGHTLY MOIST, MIXED BROWN.
q 54/ 12
SAND AND SILT (SM-ML), SLIGHTLY GRAVELLY, MEDIUM
DENSE/ST|FF, SLTGHTLY Mo|ST, BRoWN.
3e/12
GRAVEL (GM), SANDY, SILTY, SCATTERED COBBLES, VERY DENSE,
SLIGHTLY MOIST, BROWN. ROUNDED ROCK.
10
16/ 12
WC=3. I
+4=33
-200='1 8
DRIVE SAMPLE, 2-INCH I.D. CALIFORNIA LINER SAMPLE.
i DR|VE SAMPLE, 1 3/8-rNCH r.D. SpLtT Sp00N STANDARD
PINETRATION TEST.
15
28/12 68/ 12 DRIVE SAMPLE BLOW COUNT. INDICATES THAT 68 BLOWS OF
A I4O-POUND HAMMIR FALLING JO INCHES WERE RIQUIRED
TO DRIVE THE SAMPLER 12 INCHES.
F
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20
s/12
WC=6.2
*4=12
-200=49
NOTES
1. THE EXPLORATORY BORING WAS DRILLED ON JANUARY 12, 2021
WITH A 4-INCH DIAMETER CONTINUOUS FLIGHT POWER AUGER.
25 1s/12
WC=10.1
DD=1 02
2. THE LOCATION OF THE EXPLORATORY BORING WAS MEASURED
APPROXIMATELY BY PACING FROM FEATURES SHOWN ON THE
SITE PLAN PROVIDID.
3. THE ELEVATION OF THE EXPLORATORY BORING WAS OBTAINED
BY INTERPOLATION BETWEEN CONTOURS ON THE SITE PLAN
PROVIDED.
30
s/12 4. THE EXPLORATORY BORING LOCATION AND ELEVATION SHOULD BE
CONSIDERED ACCURATE ONLY TO THE DEGRIE IMPLIED BY THE
METHOD USED.
40
5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY
BORING LOG REPRTSENT THE APPROXIMATE BOUNDARIES BTTWEEN
MATERIAL TYPES AND THT TRANSITIONS MAY BE GRADUAL.
6. GROUNDWATER WAS NOT ENCOUNTERED IN THE BORING AT THE
TIME OF DRILLING,
7 LABORATORY TEST RESULTS:
WC = WATER CONTENT (%) (ASTM D 2216);
DD = DRY DENSITY (PCf) (ASTM D 2216);
+4 = PERCENTAGE RETAINED 0N N0.4 SIEVE (ASTM D 6913);
_2OO = PERCENTAGE PASSING NO, 2OO SIEVE (ASTM D 1140).
45
50/ 1.5
WC=4.5
+4=19
-200=44
20-7 -788 Kumar & Associates LOG OF TXPLORATORY BORING lis. 2
È
SAMPLE OF: Sondy Silt
FROM:Boringl@25'
WC = I0.1 %, DD = 1O2 pcf
frê
in
full, without th€ wdtt€ñ opprovol of
Kumor ond ksociot a, lnc. Sw€ll
Consolidotion t€€ting p€dormsd in
occordonco with ASil D-4546.
ADDITIONAL COMPRESSION
UNDER CONSTANT PRESSURE
DUE TO WETTING
1
JJtil
=UI
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zotr
ô
=o
lt1z.o(J
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-1
2
3
4
1 l^APPLIED PRESSURE - KSF 10
20-7 -788 Kumar & Associates SWELL_CONSOLIDATION TEST RESULTS Fig.3
100
90
80
70
60
50
40
50
20
10
o
I
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t0
20
50
40
50
60
70
80
90
=
100
.oof .oo2 .oo5 .oo9 ,of 9 .t .500 2,36 1.73
2.O
LLIMETERS
9.5 58.1 76.2 127 200,125
DIAMETER OF PARTICLES IN MI
152
CLAY TO SILT COBBLES
GRAVEL 19 % SAND 37
LIQUID LIMIT
SAMPLE OF: Very Silty Grovelly Sond (Flll)
%
PLASTICITY INDEX
SILÏ AND CLAY 44 %
FROM: Boring 1 @ 1' & 4' (Combined)
z
100
90
80
70
60
50
10
50
20
t0
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to
20
50
40
50
60
70
80
100
=
ll
il!l r..r r. I r rtlr.o19 .O37 .O75
rl
.t 50
lt rtl l-, .:.1
1 .1a 2.36
.425 2-O 152
DIAMETER OF PARTICLES IN MILLIMETERS
CLAY TO SILT COBBLES
GRAVEL 33 % SAND
LIQUID LIMIT
SAMPLE OF: Grovelly Silly Sond (Fill)
49%
PLASTICITY INDEX
FROM:Boringl@10'
SILT AND CLAY 18%
Th6s6 l6sl r6sulls opply only lo lhe
somples which wsrs lesled. Th€
l€sllng reporl sholl nol b€ reproducad,
oxc€pl In full, wllhout lhe wrlllon
opprovol of Kumor & Associoles, lnc,
Sl6v6 onqlygls l€sllng ls p6rtormed ln
occordonc€ wlth ASIM D6913, ASTM D7928,
ASTM C156 ond/qr ASTM Dl14O.
HYDROMETER ANALYSIS SIEVE ANALYSIS
CLEAR SQUARE OPENINGS
z/a" 3/a" 1 1/r'
TIME REÄDINGS U.S. SIANDARD SERIES
HRS 7
SAND GRAVEL
FIN E MEDTUM lCOanSe FINE COARSE
HYOROMEIER ANALYSIS
TIME REAOINGS
24 HRS 7 HRS
U.S. STANDARD SERIES
/:
I
SAND GRAVEL
FI NE MEDIUM COARSE FIN E COARSE
20-7 -788 Kumar & Associates GRADATION TEST RTSULTS Fig. 4¡
ò
100
90
80
70
60
50
40
30
20
to
o
o
to
20
50
,t0
50
60
70
ao
90
=
.00f ,oo2 .005 .037 .075 .r50 .300
.425 2.O
DIAMETER OF PARTICLES MEÏERS
CLAY TO SILT COBBLES
GRAVEL 12 % SAND 59
LIQUID LIMIÏ
SAMPLE OF: Sllt ond Sond wllh Grovel
PLASTICITY INDEX
SILT AND CLAY 49 %
FROM: Boring 1 G, 20'
Th6s6 16sl r€sulls qpply only lo lh€
sqmplss which woro l€slsd. fh€
losllng r€porl sholl nol b€ roproducod,
exc€pl ln full, wllhoul lh€ wrlll6n
opproyol of Kumqr & Associolôs, lnc.
Siovo qnolysls losllng ls performed in
occordonco wlth ASTM 06913, ÀSTM D7928,
ASTM Cl36 qnd/or ASTM Dt'140.
HYDROMETER ANALYSIS
24 HRS
i utñ la7 HRS
ÎIME READINGS
6ôVtñ l CUtñ ¡Vrt 4l oo1ô
U.S. SfANDARÐ SERIES
450 ¿¡O 4tô !1a
CLEAR SOUARE OPENINGS
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FINE MEDIUM COARSE FIN E COARSE
20-7 -788 Kumar & Associates GRADATION TEST RESULTS Fig.5
I(a iiffilfiåì'ffËtr''IË;n'*'*TABLE 1SUMMARY OF LABORATORY TEST RESULTSNo.20-7-788Very Silty Gravelly SandiltGravelly Silty Sand (Fill)Silt and Sand with GravelSandy SiltSOIL ÏYPE(psflUNCONFINEDCOMPRESSIVESTRENGTH("/rlPLASTICINDEXATTERBERG LIMITS%lLIQUID LIMI'fPERCENTPASSING NO.200 stEvE448I49)t493991JJ21GRADATIONSAMPLE LOCATIONDEPTHBORINGNATURALDRYDENSITYNATURALMOISTURECONTENTSAND(%)GRAVEL(f/"1t024.5IJ6.2101I and4combined102025I