HomeMy WebLinkAboutSubsoil Study for Foundation Design 07.29.2021t(trt l(umar&Assoeiaùes, lnc. 5020 County Road 154
Geotechnical and Materials Engineers Glenwood Springs, CO 91601
and Environmentatscientists phone: (970) 945_7ggs
fax: (970)945-8454
email : kaglenwood@kumarusa.com
An Employcc Owncd Compony 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 54, PHASE 3, TRONBRTDGE
BLUE HERON DRIVE
GARFTELD COUNTY, COLORADO
PROJECT NO.2l-7-437
JULY 29,2021
PREPARED FOR:
SCIB, LLC
ATTN: LUKE GOSDA
0115 BOOMERANG ROAD, SUITE 52018
ASPEN, COLORADO 81601
luke.gosda@sunriseco.com
TABLE OF CONTEN'|S
PIIRPOSE AND SI]OPE OF S'I'LIDY
PROPOSED CONSTRUCTION
SITE CONDITIONS
SUBSIDENCE POTENTIAL
FIELD EXPLORATION
SUBSURFACE CONDITIONS ..
FOIINDATION BEARING CONDITIONS
DESIGN RECOMMENDATIONS
FOUNDATIONS
FOI-INDATION AND RETAINING WALLS
FLOOR SLABS
LTNDERDRAIN SYSTEM .....
SURFACE DRAINAGE.........
LIMITATIONS
FIGURE 1 - LOCATION OF EXPLORATORY BORINGS
FIGURE 2 - LOGS OF EXPLORATORY BORINGS
FIGURE 3 - LEGEND AND NOTES
FIGURES 4 and 5 - SWELL-CONSOLIDATION TEST RESULTS
FIG-úRE 6 - GRADATIOÌ\I TEST RESULTS
TABI,E 1 - STIMMARY OF LABORATORY TEST RTSLTLTS
I
I
aJ-
1
.-2-
,-2-
..-3-
4
4
5
6
6
7
..-7 -
Kumar & Associates, lnc.Project No.2'l-7-437
PURPOSE AND SCOPE OF STUDY
This report presents the results of a subsoil study for a proposed residence to be located on
Lot 54, Phase 3, Ironbridge, Blue Heron Drive, 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 May 10, 2021.
A field exploration program consisting of exploratory borings was conducted 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.
PROPOSED CONSTRUCTION
At the time of our study, design plans for the residence were preliminary. The building is
proposed within the building envelope shown on Figure I and could include a basement level.
For the purposes of our analysis, we assume the proposed residence will be a wood frame
structure over a basement with an attached slab-on-grade garage. Grading for the structure is
assumed to be relatively minor with cut depths between about 3 to 12 feet. We assume relatively
light foundation loadings, typical of the proposed type of construction.
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 lot was vacant and appeared to have been down cut somewhat, likely during the subdivision
development. The surface of the lot slopes gently down to the north with about 4 feet of
elevation difference across the building envelope area then slopes up moderately steep atthe rear
of the lot. Vegetation consists of sparse grass and weeds.
Kumar & Associates, lnc.Project No.2'l-7'437
SUBSIDtrNCE POTtrNTIAL
The geologic conditions were described in a previous report conducted for planning and
preliminary design of the overall subdivision development by Hepwordr-Pawlak Geotechnical
(now Kumar & Associates) dated October 29, 1991, Job No. 197 327. The natural soils on the
lot mainly r.rotrsist of sandy silt and crlay allr"rvial lan depusits overlying gravel terrar:e alluvium o1'
the Roaring Fork River. The river alluvium is mainly a clast-supported deposit of rounded
gravel, cobbles, and boulders typically up to about2 to 3 feet in size in a silty sand matrix and
overlies siltstone/claystone bedrock.
Bedrock of the Pennsylvanian age Eagle Valley Evaporite underlies the Ironbridge subdivision.
These rocks are a sequence of gypsiferous shale, fine-grained sandstone and siltstone with some
massive beds of gypsum and limestone. Dissolution of the gypsum under certain conditions can
cause sinkholes to develop and can produce areas of,localized subsidence. A sinkhole occr¡rred
in the parking lot adjoining the golf cart storage tent in January, 2005 located several hundred
feet south of Lot 54 which was backfilled and compaction grouted. To our knowledge, that
sinkhole has not shown signs of reactivation such as ground subsidence since the remediation.
Sinkholes possibly related to the Evaporite were not observed in the immediate area of the
subject lot. Based on our present knowledge of the subsurface conditions at the site, it cannot be
said for certain that sinkholes related to the underlying Evaporite will not develop. The risk of
future ground subsidence on Lot 54 throughout the service life of the proposed building, in our
opinion, is low; however, the owner should be made aware of the potential for sinkhole
development. If further investigation of possible cavities in the bedrock below the site is desired,
we should be contacted.
FIELD EXPLORATION
The f,reici expioration for the project was conciucteci on June i 5,2û2i. Two expioratory 'oorings
were drilled at the locations shown on Figure 1 to evaluate the subsurface conditions. The
borings were advanced with 4-inch diameter continuous flight augers powered by a truck-
mounted CME-458 drill rig. The borings were logged by a representative of Kumar &
Associates, Inc.
Sarnples of the subsoils were taken with l%-inch and 2-inch I.D. spoon samplers. The samplers
were clriven into the subsoils at various depths with blows from a 140-pountl hammer falling
30 inches. This test is similar to the standard penetration test described by ASTM Method D-
1586. The penetration resistance values are an indication of the relative density or consistency of
Kumar & Associates, lnc.Project No. 2l-7-437
-3 -
the subsoils. Depths at which the samples were taken and the penetration resistance values are
shown on the Logs of Exploratory Borings, Figure 2. The samples were returned to our
laboratory for review by the project engineer and testing.
SUBSURFACE CONDITIONS
Graphic logs of the subsurface conditions encountered at the site are shown on Figure 2. The
subsoils encountered in the borings consist of very stiff, sandy clay to between 9 and 13 feet
deep where dense, silty sandy gravel with cobbles and probable boulders was encountered to the
maximum explored depth of l7 feet. Drilling in the dense granular soils with auger equipment
was difficult due to the cobbles and boulders and drilling refusal was encountered in Boring 1 at
a depth of 15 feet and in Boring 2 at a depth of 17 feet.
Laboratory testing performed on samples obtained frorn the borings included natural moisture
content and density and gradation analyses. Results of swell-consolidation testing performed on
relatively undisturbed drive samples of clay soils, presented on Figures 4 and 5, indicate low to
moderately high compressibility under conditions of loading and wetting. Results of a gradation
analysis performed on a small diameter drive sample (minus Ilz-inch fraction) of the granular
soils are shown on Figure 6. The laboratory testing is summarizedin Table 1.
No free water was encountered in the borings at the time of drilling and the subsoils were
slightly moist.
FOUNDATION BEARING CONDITIONS
The clay soils encountered at foundation level have a low bearing capacity and tend to settle
mainly when wetted under load. There is also a difference in the thickness of the clay soils
across the building area which can increase the differential settlement and building distress risk.
The amount of settlernent or differential movement will be mainly related to the depth of clay
soils and extent of subsurface wetting. It will be critical to the long-term performance of the
structure that the recolnmendations for surface drainage contained in this report be followed.
Recommended forms of settlement mitigation include: l) deep compaction,2) adeep foundation
such as drilled piers or helical piers bearing on the underlying dense gravel and cobble soils, or
3) sub-excavation of the clay soils down to the natural granular soils and replacement with
compacted structural fill.
The footing bearing level on Lof 54 could also be deepened to limit the depth of clay soils to
around 6 feet below the bearing level as a foundation settlement mitigation measure. In sub-
Kumar & Associates, lnc.Project No.21-7-437
-4-
excavated areas, the on-site soils or road base could be replaced compacted to reestablish design
bearing level. For typical shallow footing depth of 3 feet, the depth of structural fill should be
around 3 feet helow footing hearing level.
Recommendations for a spread footing foundation are presented below. If a deep foundation or
other type foundation is desired. we should be contacted for additional analysis and
recommendations.
DESIGN RE,COMMENDATIONS
FOUNDATIONS
Considering the subsurface conditions encountered in the exploratory borings and the nature of
the proposed construction, the building can be founded with spread footings bearing on the
natural clay or granular soils or compacted structural fill with a settlement risk.
The design and construction criteria presented below should be observed for a spread footing
foundation system.
1) Footings placed on up to 6 feet of the undisturbed natural clay soils, compacted
structural fill, or natural granular soils should be designed for an allowable
bearing pressure of 1,500 psf. Footings placed entirely on the natural granular
soils can be designed for an allowable bearing pressure of 3000 psf. Based on
experience, we expect initial settlement of footings designed and constructed as
discussed in this sectiôn will be about 1 inch or less. Additional differential
settlement up to about I inch could occur if the clay bearing soils are wetted.
2) The fool.ings should have a minimutn width of 20 inches for conlinuous walls ancl
2 feet for isolated pads.
3) Exterior footings and footings beneath unheated areas should be provided with
aciequate soii cover above their bearing elevation f'or fiost protection. Placement
of foundations at least 36 inches below exterior grade is typically used in this
area.
4) Continuous foundation walls 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 should also be designed to resist
lateral earth pressures as discussed in the "Foundation and Retaining Walls"
section ofthis report.
5) The topsoil, sub-excavation as needed to achieve less than 6 feet depth of clay
soils and loose or disturbed soils should be removed in footing areas. The
Kumar & Associotes, lnc.Project No.21.7'437
5
exposed soils in footing areas should then be moistened and compacted.
Structural fill should extend laterally beyond the footing edges a distance at least
%the f,rll depth below the footing and be compacted to at least 98% of the
standard Proctor density atnear optimum moisture content.
A representative of the geotechnical engineer should observe all footing
excavations prior to concrete placement to evaluate bearing conditions.
FOLTNDATION AND RETAINING WALLS
Foundation walls and retaining structures 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 55 pcf for backfill consisting
of the on-site soils. Cantilevered retaining structures which are separate from the residence and
can be expected to deflect sufhciently 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 45 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, traffic, construction materials and equipment. The
pressures recommended above assume drained conditions behind the walls and a horizontal
backfill surface. The buildup of water behind a wall or an upward sloping backfill 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.
Backfill should be placed in uniform lifts and compacted to at least 90Yo of the maximum
standard Proctor density at near optimum moisture content. Backf,rll placed in pavement and
walkway areas should be compacted to at least 95o/o of fhe maximum standard Proctor density.
Care should be taken not to overcompact the backhll 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. Backfill should not contain organics, debris or rock larger
than about 6 inches.
The lateral resistance of foundation or retaining wall footings will be a cornbination 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
6)
Kumar & Associates, lnc,Project No.21-7-437
-6-
sides of the footings can be calculated using an equivalent fluid unit weight of 325 pct'. 'l'he
coefficient of triction attd 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 95o/o of the
tnaxitttum standard Proc[or clensity at a moisture content near optimum.
FLOOR SLABS
The natural on-site soils, exclusive of topsoil, are suitable to support lightly loaded slab-on-grade
construction with a risk of settlement if the bearing soils are wetted. To reduce the effects of
some differential movement, floor slabs should be separated from all bearing walls and columns
with expansion joints which allow unrestrained vertical movement. Floor slab control joints
shoulcl be usecl 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 rninimum 4-inch layer of relatively well graded sand and gravel such as
road base should be placed beneath interior slabs for support. This material should consist of
minus 2-inch aggregate with at least 50% retained on the No. 4 sieve and less than I2Yo passing
the No. 200 sieve.
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 soils devoid of vegetation and topsoil or a suitable imported material such as road base.
LTNDERDRATN SYSTEM
Although free water was not encountered during our exploration, it has been our experience in
the area and where there are clay soils that local perched groundwater can develop during times
of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can create a
perched condition. We recommend helow-grade constnlction, such as retaining walls and
basement areas, be protected from wetting and hydrostatic pressure buildup by an underdrain
system. Shallow crawlspace up to around 4 feet deep and slab-at-grade garagc arcas should not
need a perimeter underdrain with proper backfill placcment and surface grading.
The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above
the invert level with free-draining granular material. The drain should be placed at each level of
excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum IYo to
a suitable gravity outlet, drywell based in the coarse granular subsoils or sump pit. Free-draining
Kumar & Associates, lnc.ProJect No. 21.7.437
,7
granular material used in the underdrain system should contain less than 2Yo passing the No. 200
sieve, less than 50% passing the No. 4 sieve and have a maximum size of 2 inches. The drain
gravel backf,rll should be at least IYz feet deep. An impervious membrane such as 20 mil PVC
should be placed beneath the drain gravel in a trough shape and attached to the foundation wall
with mastic to prevent wetting of the bearing soils.
SURFACE DRAINAGE
It will be critical to the long-term building performance to keep the bearing soils dry. The
following drainage precautions should be observed during construction and maintained at all
times after the residence has been completed:
1) Inundation of the foundation excavations and underslab areas should be avoided
during construction.
2) Exterior backfill should be adjusted to near optimum moisture and compacted to
at least 95"/o of the maximum standard Proctor density in pavement and slab areas
and to at least 90o/o of the maximum standard Proctor density in landscape areas.
Free-draining wall backfill should be covered with filter fabric and capped with
about 2 feet of the on-site soils to reduce surface water infiltration.
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 l2 inches in the first 10 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 well beyond the limits of all
backfill.
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 irnplied.
The conclusions and recommendations submitted in this report are based upon the data obtained
from the exploratory borings drilled at the locations 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
Kumar & Associates, lnc.Project No.21-7-437
-8-
in the fìrture. 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
subsurface conditions identificd at thc cxploratory borings and variations in the suhsurface
conditions may not become evident unl.il exoavation is performetl. If contlil"ions encountered
during construction appear difTerent 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 evolveso we
should provide continued consultation and field services during construction to review and
monitor the implementation of our recommendations, and to veri$r 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.
}n"t tr*. Pa,tr¿v¿¿.¿
James H. Parsons, P.E.
Reviewed by:
Steven L. Paw
JHP/kac
162?,.
z
Kumar & Associates, lnc,Project No.2l-7-437
\
ô¿ü¿
PROPERTY
LINE
aQ ) |tr%
oo4,t
53
02 .4,
1,,.0
'79
PROPERTY
I,TNE
LOT 55
99 SETBACK 1C
15 0 0
APPROXIMATE SCALE-FEET
o
?o nl
PROPERTY
LINE
BORING 1
,Oo
BORING 2 LOT 54 102.0'
SETBACK 1,,0
,O6
21 -7 -437 Kumar & Assocíates LOCATION OF TXPLORATORY BORINGS 1Fig.
I
BORING 1
EL. 1 02'
BO
EL.
R ING 2
5'105
110 110
105 105
11 /12
WC=7.3
DD=92
t-
t¡Jt¡l
t!
I
z.o
t-
L¡JJ
LJ
100
21 /12
WC=5.9
DD= 1 06
-200=83
18/ 12 100 Ft¡l
ÙJ
L!
IzoË
LdJtij
1e/12
WC=4.5
DD=99
14/12
95
3s/ 12
tNC=11 .2
DD=1 1 4
-200=95
95
23/ 12
35/6,50/4
qn 36/6,50/s
WC=0.3
*4=60
-200=8
90
85 B5
LEGEND:
ASSUMED BASEMENT LEVEL 93"
21-7 -437 Kumar & Associates LOGS OF TXPLORATORY BORINGS Fig. 2
I
I
LEGEND
CLAY (CL); SILTY, SANDY, VERY STIFF, SLIGHTLY MOIST, MIXED BROWN
F:.Ztl: ,/<:1
6:)l:/s!lw;
GRAVEL
BROWN
(GM); SILTY, SANDY, COBBLES, PROBABLE BOULDERS' DENSE, SLIGHTLY MOIST,
AND TAN. ROUNDED ROCKS.
DRIVE SAMPLE, 2_INCH I.D. CALIFORNIA LINER SAMPLE
i DR|VE SAMPLE, 1 3/8-INCH l.D. SPLIr SPOON STANDARD PENETRATION TEST
ã. I.^ DRIVE SAMPLE BLOW COUNT. INDICATES THAT 21 BLOWS OF A 14o-POUND HAMMER¿t/ t¿ FALLTNc Jo TNcHES wERE REeUIRED To DRtvE THE SAMPLER 12 lNcHES.
I PRACTICAL AUGER REFUSAL.
NOTES
1 , THE EXPLORATORY BORINGS WERE DRILLED ON JUNE 1 5, 2021 WITH A 4-INCH DIAMETER
CONTINUOUS_FLIGHT POWER AUGER.
2. THE LOCATIONS OF THE EXPLORATORY BORINGS WERE MEASURED APPROXIMATELY BY PACING
FROM FEATURES SHOWN ON THE SITE PLAN PROVIDED.
3. THE ELEVATIONS OF THE EXPLORATORY BORINGS WERE OBTAINED BY INTERPOLATION BETWEEN
CONTOURS ON THE SITE PLAN PROVIDED AND ASSUMED CONTOUR ELEVATIONS.
4, THE EXPLORATORY BORING LOCATIONS AND ELEVATIONS SHOULD BE CONSIDERED ACCURATE
ONLY TO THE DEGREE IMPLIED BY THE METHOD USED.
5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY BORING LOGS REPRESENT THE
APPROXIMATE BOUNDARIES BETWEEN MATERIAL TYPES AND THE TRANSITIONS MAY BE GRADUAL
6. GROUNDWATER WAS NOT ENCOUNTERED IN THE BORINGS AT THE TIME OF DRILLING
7. LABORATORY TEST RESULTS:
WC = WATER CONTENT (%) (ASTM D2216);
DD = DRY DENSITY (PCt) (ASTV D2216);
+4 = PERCENTAGE RETAINED ON NO. 4 SIEVE (ASTM D6913);
-2OO= PERCENTAGE PASSING N0. 200 SIEVE (ASTM D1140).
21-7 -437 Kumar & Associates LEGEND AND NOTES Fig.5
I
I
¡
SAMPLE 0F: Sondy Silty Cloy
FROM;Boring1@5'
WC = 4.5 %, DD = 99 pcf
ADDITIONAL COMPRESSION
UNDER CONSTANT PRESSURE
DUE TO WETTING
I
i
l
I
I
I
1
l
l
1
JJ
l¡J
=Ø
I
zotr
ô
=o
U)z.o
(_)
0
-1
2
3
-4
1.0 APPLIEU PKISSURE _ KSF t0 100
21 -7 -437 Kumar & Associates SWELL_CONSOLIDATION TTST RISULTS Fig. 4
E
a
I
I
I
L
I
i
I
SAMPLE OF: Sondy Silty Cloy
FROM:Boring2@2.5'
WC = 7.5 %, DD = 92 pcf
I
!
I
I
ADDITIONAL COMPRESSION
UNDER CONSTANT PRESSURE
DUE TO WEÏTING
lÌl
I
I
ì
i
i
l
l
l
l
I
ì
I
l
I
I
l
I
I'
i
I
I
I
i
I
I
l
r
l
l
l
I
I
I
I
l
l
l
l
ì
l
I
:
l
I
I
I
t4t
v¡th
w¡thout th.
2
0
JôJ-Z
l¡J
=U)
t_4
z.otr
ôf-ooØz.o<)-8
-10
-12
.0 APPLIED PRESSURE - KSF 100
21 -7 -437 Kumar & Associates SWELL-CONSOLIDATION TEST RESULTS Fig. s
e
n
É
ã
r00
90
00
70
60
50
40
30
20
t0
0
0
10
2U
30.
10
50
60
70
60
90
too
z
E
H
150 .300
2.O
DIAMETER OF IN
CLAY TO SILT COBBLES
GRAVEL 60 % SAND 32
LIQUID LIMIT
SAMPLE OF: Sllghtly Sllty Sondy Grovel
PLASTICITY INDEX
SILT AND CLAY A %
FROM:Boring2O15'
Th.e. hsl resulls opply only lo lhe
sompls! whlch woro l6slod, Th!
lo3llng roporl ehqll nol br reproduced,
oxcepl ln full, wllhoul lh€ wrltlonqpproyol of Kumor & Assoslqlos, lnc.
Sl.vc onolysls lodlng b porformcd ln
occordonc€ wllh ASTM 06913, ASTM D7928,
ASTM Cl56 qndlor ASIM 01140.
HYDROMETER ANALYSIS SIEVE ANALYSIS
rIME REAOTNGS
!4 llng 7 llnsaå llN i a lrN âôllN r eltN MN¡!tN
U.S. SÍANDARD SERIES CLEAR SQUARE OPENII{Os
./r' 1/^' t trtn
'- t-'
,.-1--
- -1- '.-_t__J--
----
t-J __l
I
---l--I ---¡,-+-- --
4--.,-+
+-
=--+
+
l
-,-, -t--t-
l -1*-t--
----l-
SAND GRAVEL
FINE MEDTUM ICOARSE FINE COARSE
21-7 -437 Kumar & Associates GRADATION TEST RESULTS Fig.6
rcrf å:ffi1fi'ff:ir:fftrn'"'Êü**'
TABLE 1
SUMMARY OF LABORATORY TEST RESULTS
SOIL TYPE
Sandy Silty Clay1065.92y,831
BORING
ATTERBERG LIMITSGRADATIONLOCATION
DEPTH LIQUID LIMIT
UNCONFINED
COMPRESSIVE
STRENGTH
PERCENT
PASSING NO.
200 stEvE
NATURAL
DRY
DENSITY
NATURAL
MOISTURE
CONTENT
SAND
$t
GRAVEL
(%)
PLASTIC
INDEX
Sandy Silty Clay
Sandy Silty Clay
3260
II4 95
8
Slightly Sandy Silty Clay
Slightly Silty Sandy Gravel
92
994.3
t.3
tt.2
0.35I
5
2/,
01
2
No.21-7-437