HomeMy WebLinkAboutSoils Report 03.31.2020It -A
Kumar & Associates, Inc.®
Geotechnical and Materials Engineers
and Environmental Scientists
An Employee Owned Company
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 ADDITIONS TO EXISTING HOUSE
1675 COUNTY ROAD 109
GARFIELD COUNTY, COLORADO
PROJECT NO. 20-7-148
MARCH 31, 2020
PREPARED FOR:
RIDGE RUNNER CONSTRUCTION
ATTN: BRENT LOUGH
1655 COUNTY ROAD 109
GLENWOOD SPRINGS, COLORADO 81601
blridgerunner@gmail.com
TABLE OF CONTENTS
PURPOSE AND SCOPE OF STUDY - 1 -
PROPOSED CONSTRUCTION - 1 -
SITE CONDITIONS - 1 -
SUBSIDENCE POTENTIAL - 2 -
FIELD EXPLORATION - 2 -
SUBSURFACE CONDITIONS - 3 -
FOUNDATION BEARING CONDITIONS - 3 -
DESIGN RECOMMENDATIONS - 4 -
FOUNDATIONS - 4 -
MICRO -PILES - 4 -
FOUNDATION ALTERNATIVE (GARAGE ONLY) - 4 -
FOUNDATION AND RETAINING WALLS - 5 -
UNDERDRAIN SYSTEM - 6 -
SURFACE DRAINAGE - 7 -
LIMITATIONS - 8 -
FIGURE 1 - LOCATION OF EXPLORATORY BORINGS
FIGURE 2 - LOGS OF EXPLORATORY BORINGS
FIGURE 3 - LEGEND AND NOTES
FIGURES 4 through 6 - GRADATION TEST RESULTS
TABLE 1- SUMMARY OF LABORATORY TEST RESULTS
Kumar & Associates, Inc. ° Project No. 20-7-148
PURPOSE AND SCOPE OF STUDY
This report presents the results of a subsoil study for proposed additions to an existing residence
located at 1675 County Road 109, 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 Ridge Runner Construction dated February 14, 2020. H-P Geotech (now Kumar &
Associates) performed a subsoil study for the existing house on this site in a reported dated
January 27, 2015, Job No. 114-187A.
A field exploration program consisting of exploratory borings was conducted to obtain
information on the subsurface conditions. Samples of the subsoils and bedrock obtained during
the field exploration were tested in the laboratory to determine their classification and other
engineering characteristics. The results of the field exploration and laboratory testing were
analyzed to 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
The proposed additions will include a detached single story garage and a single story casita.
Ground floor will be structural over crawlspace in the casita and slab -on -grade in the garage.
Grading for the structures is assumed to be relatively minor with cut depths between about 2 to
5 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 subject site was developed with a one and two story residence at the time of our field
exploration. The overall slope in the proposed building area is moderately sloping down to the
Kumar & Associates, Inc. ° Project No. 20-7-148
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east. The lot becomes steeper uphill to the west of the building area. The grade has been
modified near the existing residence for the asphalt driveway and the residence. The area of the
existing driveway was previously graded relatively nearly flat in the area of our borings.
Vegetation consists of grass, weeds and juniper bushes.
SUBSIDENCE POTENTIAL
Bedrock of the Pennsylvanian age Eagle Valley Evaporite underlies the subject site. These rocks
are a sequence of gypsiferous shale, fine-grained sandstone and siltstone with some massive beds
of gypsum and limestone. There is a possibility that massive gypsum deposits associated with
the Eagle Valley Evaporite underlie portions of the lot. Dissolution of the gypsum under certain
conditions can cause sinkholes to develop and can produce areas of localized subsidence.
During previous work in the area, several sinkholes have been identified in this part of the
Roaring Fork River Valley. These sinkholes appear similar to others associated with the Eagle
Valley Evaporite in areas of the Eagle Valley.
Sinkholes were not observed in the immediate area of the subject lot. No evidence of cavities
was encountered in the subsurface materials. Based on our present knowledge of the subsurface
conditions at the site, it cannot be said for certain that sinkholes will not develop. The risk of
future ground subsidence on this site throughout the service life of the proposed additions, 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 field exploration for the project was conducted on March 17, 2020. Two exploratory
borings 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-45B drill rig. The borings were logged by a representative of Kumar &
Associates, Inc.
Samples of the subsoils were taken with 1% inch and 2 inch I.D. 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
Kumar & Associates, Inc. ° Project No. 20-7-148
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D-1586. The penetration resistance values are an indication of the relative density or consistency
of the subsoils and hardness of the bedrock. 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 consist of about up to 6 inches of crushed rock fill overlying alluvial fan deposits
composed of interlayered loose to dense silty to very silty sand and gravel. Eagle Valley
Evaporite bedrock was apparently encountered at about 66 feet in Boring 2, although intact
samples of the formation rock were not recovered. Drilling in the dense granular soils with
auger equipment was difficult at depth due to the cobbles and boulders and drilling refusal was
encountered at 42'/2 feet in Boring 1. The soils consist of colluvium derived from the Eagle
Valley Evaporite bedrock which outcrops uphill to the west of the site.
Laboratory testing performed on samples obtained from the borings included natural moisture
content, density and gradation analyses. Results of gradation analyses performed on small
diameter drive samples (minus 11/2-inch fraction) of the coarse granular subsoils are shown on
Figures 4 through 6. The laboratory testing is summarized in Table 1. Based on the moisture
content, density and percent finer than sand size gradation analyses, the upper 50 feet of soil has
moderate collapse potential (settlement under constant load) when wetted.
No free water was encountered in the borings at the time of drilling and the subsoils were
generally slightly moist.
FOUNDATION BEARING CONDITIONS
The soils at the site down to a depth of about 65 feet consist of low to moderate collapse
potential, interlayered silts, sands and gravels composed of Eagle Valley Evaporite fragments.
Based on previous experience in the area, we estimate that these soils have an overall settlement
potential of about 2% if wetted. Depending on the depth of future wetting, the potential
settlement could be 6 to 12 inches. In order to mitigate this potential settlement, the casita and
garage can be supported on relatively deep piles, such as micro -piles end -bearing in the
underlying bedrock. Provided the detached garage is designed to withstand potential large
Kumar & Associates, Inc. ° Project No. 20-7-148
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differential settlement and will not contain living space, a heavily reinforced mat slab foundation
could be used. Recommendations for these two foundation alternatives are provided below.
Lower floors for the pile foundation should be structurally supported over a crawlspace.
Exceptionally good surface drainage away from the house and elimination of all irrigation will
be critical to prevent wetting of the bearing soils. The precautions contained in the Surface
Drainage Recommendations section below should be followed.
DESIGN RECOMMENDATIONS
FOUNDATIONS
Considering the subsurface conditions encountered in the exploratory borings, our experiences
with the previous building on the property and the nature of the proposed construction, we
recommend the casita and garage be founded with micro -piles that extend down into the
bedrock.
MICRO -PILES
The proposed construction should be supported on micro -piles drilled down into the underlying
bedrock. The micro -pile capacity can be calculated based on an end -bearing capacity of 10,000
psf and a skin friction of 2,000 psf for that portion of the pile in bedrock. Downdrag due to
potential settlement of the upper 60 feet of soil can be taken as 1,000 psf for the outside surface
area of the upper 20 feet of pile. A pipe sleeve in the upper part of the pile could be needed to
reduce the downdrag on the pile. We should review the micro -pile design prior to construction.
FOUNDATION ALTERNATIVE (GARAGE ONLY)
The design and construction criteria presented below should be observed for a mat slab
foundation system.
1) A mat slab placed on a minimum 5 feet depth of on -site compacted soils should
be designed for an allowable bearing pressure of 1,000 psf. Based on experience,
we recommend the mat be reinforced to allow an unsupported corner of at least
10 feet.
2) We expect the mat slab will be 11/2 to 2 feet thick if conventionally reinforced. A
post -tensioned slab might be thinner. The slab should extend out to support any
structural supports such as attached deck/porch columns.
Kumar & Associates, Inc. ° Project No. 20-7-148
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3) The mat slab should be provided with adequate soil cover above its bearing
elevation for frost protection. Placement of foundations at least 36 inches below
exterior grade is typically used in this area. As an alternative, shallow mat slab
edges can be protected against frost by providing insulation in accordance with
the 2009 International Residential Code.
4) Continuous foundation walls (grade beams) should be 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 of this report.
5) All existing fill, topsoil, any loose disturbed soils and the upper soils should be
removed to a minimum depth of 5 feet below the mat slab bearing level and to at
least 5 feet beyond the mat slab edges. The exposed soils in excavation area
should then be moistened and compacted. The on -site soils should be replaced,
compacted to at least 98% of standard Proctor density within 2% of optimum
moisture content.
6) A representative of the geotechnical engineer should observe the mat slab
subgrade excavation and evaluate structural fill compaction prior to concrete
placement.
FOUNDATION 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 50 pcf for backfill consisting
of the on -site soils. Cantilevered retaining structures which are separate from the additions and
can be expected to deflect sufficiently 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. Retaining structures separate from
the proposed structures can be supported on spread footings designed for an allowable soil
bearing pressure of 1,500 psf provided that they can tolerate the relatively large potential
settlements at this site.
Kumar & Associates, Inc. ® Project No. 20-7-148
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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 90% of the maximum
standard Proctor density at a moisture content near optimum. Backfill in pavement and walkway
areas should be compacted to at least 95% 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 0.40. Passive pressure of compacted backfill against the
sides of the footings can be calculated using an equivalent fluid unit weight of 350 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 95% of the
maximum standard Proctor density at a moisture content near optimum.
UNDERDRAIN SYSTEM
Although free water was not encountered during our exploration, it has been our experience in
the area 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 below -grade construction, such as retaining walls and deeper crawlspace areas be
protected from wetting and hydrostatic pressure buildup by an underdrain system. Mat slab at
grade and shallow crawlspaces (up to 4 feet deep) should not have an underdrain.
Kumar & Associates, Inc. ° Project No. 20-7-148
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If installed, 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 1 % to a suitable gravity outlet or sump and pump. Free -draining granular
material used in the underdrain system should contain less than 2% passing the No. 200 sieve,
less than 50% passing the No. 4 sieve and have a maximum size of 2 inches. The drain gravel
backfill should be at least 11/2 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
The following drainage precautions should be observed during construction and maintained at all
times after the additions have 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% of the maximum standard Proctor density in pavement and slab areas
and to at least 90% 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 12 inches in the first 10 feet in unpaved areas and a minimum slope of
3 inches in the first 10 feet in paved areas. Unlined drainage swales should have a
minimum grade of 4%. Free -draining wall backfill (if any) should be covered
with filter fabric and capped with at least 2 to 3 feet of the on -site soils to reduce
surface water infiltration.
4) Roof downspouts and drains should discharge well beyond the limits of all
backfill.
5) Landscaping which requires regular heavy irrigation (sod) should preferably not
be installed at the site. If used, it should be located at least 15 feet from the
building perimeters. Preferably, xeriscape that requires minimal irrigation should
be used to reduce the potential for wetting of soils below the building caused by
irrigation.
Kumar & Associates, Inc. ° Project No. 20-7-148
8
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 borings drilled excavated 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 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 subsurface conditions identified at the exploratory borings 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 verify 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.
James H. Parsons, E.I.
Reviewed by:
Daniel E. Hardin,
JHP/kac
cc: Kaup Engineerin
ale(akaupengineering. com)
Kumar & Associates, Inc.
Project No. 20-7-148
25 0 25 50
APPROXIMATE SCALE -FEET
20-7-148
Kumar & Associates
LOCATION OF EXPLORATORY BORINGS
Fig. 1
0
BORING 1
EL. 101'
BORING 2
EL. 100'
0
N
0)
DEPTH -FEET
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
0
011
0
0
10/12
WC=9.8
DD=107
- 200=21
12/12
WC=7.7
DD=105
- 200=19
50/5
15/12
WC=6.8
+4=30
- 200=34
12/12
WC=9.5
DD=102
- 200=51
34/12
WC=3.0
DD=126
- 200=33
27/12
WC=3.0
+4=30
- 200=36
75/12
WC=13.2
DD=121
- 200=48
14/12
WC=9.3
J DD=118
7
ATI
15/12
WC=6.2
DD=111
23/12
WC=3.9
+4=43
- 200=30
50/12
30/12
32/12
49/12
WC=2.9
DD=127
- 200=28
68/12
WC=2.9
+4=42
- 200=29
50/1
WC=3.1
DD=135
- 200=47
65/6
WC=3.7
DD=125
- 200=51
50/2
7
50/3
75
80
85
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
LOGS OF EXPLORATORY BORINGS
Kumar & Associates
20-7-148
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LEGEND
GRAVEL: 3/4 INCH CRUSHED ROCK.
SAND (SM): SILTY, GRAVELLY, MEDIUM DENSE, MOIST, BROWN.
GRAVEL AND SAND (GM): SILTY TO VERY SILTY, COBBLES, PROBABLE BOULDERS, MEDIUM
DENSE TO DENSE, SLIGHTLY MOIST, BROWN.
SILTSTONE/SANDSTONE (MS/SS): WEATHERED TO HARD, SLIGHTLY MOIST, TAN AND BROWN.
DRIVE SAMPLE, 2—INCH I.D. CALIFORNIA LINER SAMPLE.
DRIVE SAMPLE, 1 3/8—INCH I.D. SPLIT SPOON STANDARD PENETRATION TEST.
10/12 DRIVE SAMPLE BLOW COUNT. INDICATES THAT 10 BLOWS OF A 140—POUND HAMMER
FALLING 30 INCHES WERE REQUIRED TO DRIVE THE SAMPLER 12 INCHES.
t PRACTICAL AUGER REFUSAL.
NOTES
1. THE EXPLORATORY BORINGS WERE DRILLED ON MARCH 17, 2020 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 MEASURED BY HAND LEVEL AND REFER
TO BORING 2 AS A 100' BENCHMARK.
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 (pcf) (ASTM D2216);
+4 = PERCENTAGE RETAINED ON NO. 4 SIEVE (ASTM D6913);
—200= PERCENTAGE PASSING NO. 200 SIEVE (ASTM D1140).
20-7-148
Kumar & Associates
LEGEND AND NOTES
Fig. 3
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PERCENT PASSING
N W A U V D 8 O
O O O O O O O O O O
HYDROMETER ANALYSIS
SIEVE ANALYSIS
O m S V O 0O O W N O
00
PERCENT RETAINED
TIME READINGS
24 HRS 7 HRS
45 MIN 15 MIN 60MIN 19MIN 4MIN 1MIN 0200
U.S. STANDARD SERIES
41100 #50 #40 #_30 0
6 010 /8 $4
CLEAR SQUARE OPENINGS
3 8" 3 4" 1 1 2" 3" 5"6" 8
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.001 .002
.005 .009 .019 .037 .075
DIAMETER
.150 .300 I .600 1.18 12.36 4.75
.425 2.0
OF PARTICLES IN MILLIMETERS
9 5 19 38.1 76.2 127
152
200
SAND
GRAVEL
CLAY TO SILT
FINE MEDIUM COARSE
FINE COARSE
COBBLES
GRAVEL 30 %
LIQUID LIMIT
SAMPLE OF: Silty Sand and Gravel
SAND 36 % SILT
PLASTICITY INDEX
FROM:
AND CLAY 34 %
Boring 1 0 15'
pPERCENT PASSING O 0 O O O O O O O O O
HYDROMETER ANALYSIS
SIEVE ANALYSIS
24 HRS
45 MIN
TIME READINGS
7 HRS
15 MIN 60MIN 19MIN 4MIN 1MIN 0200
U.S. STANDARD SERIES
0100 #50 Y40 #30 #116 1110
18
CLEAR SQUARE OPENINGS
4 3/8" 3 4" 1 1 2" 3" 51'6" 8'0
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100
.001 .002 .005 .009 .019 .037 .075 .150 .300 I .600 1. 8 12.36 4.75 9 5 19 38.1 76.2 127
.425 2.0 152
DIAMETER OF PARTICLES IN MILLIMETERS
200
SAND
GRAVEL
CLAY TO SILT
FINE MEDIUM COARSE
FINE COARSE
COBBLES
GRAVEL 30 % SAND 34 % SILT AND CLAY 36 %
LIQUID LIMIT PLASTICITY INDEX
These test results apply only to the
SAMPLE OF: Silty Sand and Gravel FROM: Boring 1 0 30' samples which were tested. The
testing report shall not be reproduced,
except in full, without the written
approval of Kumar & Associates, Inc.
Sieve analysis testing is performed in
accordance with ASTM D6913, ASTM D7928,
ASTM C136 and/or ASTM D1140.
20-7-148
Kumar & Associates
GRADATION TEST RESULTS
Fig. 4
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PERCENT PASSING
N W A U V D 8 O
O O O O O O O O O O
HYDROMETER ANALYSIS
SIEVE ANALYSIS
O m S V O 0O O W N O
00
PERCENT RETAINED
TIME READINGS
24 HRS 7 HRS
45 MIN 15 MIN 60MIN 19MIN 4MIN 1MIN 0200
U.S. STANDARD SERIES
41100 #50 #40 #_30 0
6 010 #8 $4
CLEAR SQUARE OPENINGS
3/8" 3L4" 1 1 2" 3" 8
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1"6"
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1 1 1 1
1 1 1 I
.001 .002
.005 .009 .019 .037 .075
DIAMETER
.150 .300 I .600 1.18 12.36 4.75
.425 2.0
OF PARTICLES IN MILLIMETERS
9 5 19 38.1 76.2 127
152
200
SAND
GRAVEL
CLAY TO SILT
FINE MEDIUM COARSE
FINE COARSE
COBBLES
GRAVEL 43 %
LIQUID LIMIT
SAMPLE OF: Silty Sandy Gravel
SAND 27 % SILT
PLASTICITY INDEX
FROM:
AND CLAY 30 %
Boring 2 0 10'
pPERCENT PASSING O 0 O O O O O O O O O
HYDROMETER ANALYSIS
SIEVE ANALYSIS
24 HRS
45 MIN
TIME READINGS
7 HRS
15 MIN 60MIN 19MIN 4MIN 1MIN 0200
U.S. STANDARD SERIES
0100 #50 Y40 #30 #116 010
I8
CLEAR SQUARE OPENINGS
4 3/8" 3 4" 1 1 2" 3" 8'0
T6"
10
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20
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8
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60
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70
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80
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90
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1 1
1111
1 1
1111111
1
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1111
1
1 1111111
1 1
1111111
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100
.001 .002 .005 .009 .019 .037 .075 .150 .300 I .600 1. 8 12.36 4.75 9 5 19 38.1 76.2 127
.425 2.0 152
DIAMETER OF PARTICLES IN MILLIMETERS
200
SAND
GRAVEL
CLAY TO SILT
FINE MEDIUM COARSE
FINE COARSE
COBBLES
GRAVEL 35 % SAND 27 % SILT AND CLAY 38 %
LIQUID LIMIT PLASTICITY INDEX
These test results apply only to the
SAMPLE OF: Silty Sand and Gravel FROM: Boring 2 0 15' & 20' samples which were tested. The
testing report shall not be reproduced,
except in full, without the written
approval of Kumar & Associates, Inc.
Sieve analysis testing is performed in
accordance with ASTM D6913, ASTM D7928,
ASTM C136 and/or ASTM D1140.
20-7-148
Kumar & Associates
GRADATION TEST RESULTS
Fig. 5
PERCENT PASSING
O O N W O N O O
HYDROMETER ANALYSIS
SIEVE ANALYSIS
O O
m 00 O O O O O V 00 A W N O 00
O O
O
PERCENT RETAINED
TIME READINGS
24 HRS 7 HRS
45 MIN 15 MIN 60MIN 19MIN 4MIN 1MIN #200
U.S. STANDARD SERIES
#100 #50 #40 #30 #
6 #10 #8 #4
CLEAR SQUARE OPENINGS
3L8" 3 4" 1 1 2" 3" 8
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1 1 1
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1
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1 1 1 I
.001 .002 .005 .009 .019 .037 .075 .150 .300 I .600 1.18 12.36 4.75 9 5 19 38.1 76.2 127
.425 2.0 152
DIAMETER OF PARTICLES IN MILLIMETERS
200
SAND
GRAVEL
CLAY TO SILT
FINE MEDIUM COARSE
FINE COARSE
COBBLES
GRAVEL 42 % SAND 29 % SILT AND CLAY 29
LIQUID LIMIT PLASTICITY INDEX
SAMPLE 0F: Silty Sandy Gravel FROM: Boring 2 ® 40'
These test results apply only to the
samples which were tested. The
testing report shall not be reproduced,
except in full, without the written
approval of Kumar & Associates, Inc.
Sieve analysis testing is performed in
accordance with ASTM D6913, ASTM D7928,
ASTM C136 and/or ASTM D1140.
20-7-148
Kumar & Associates
GRADATION TEST RESULTS
Fig. 6
K+A
Kumar & Associates, Inc.
Geotechnical and Materials Engineers
and Environmental Scientists
TABLE 1
SUMMARY OF LABORATORY TEST RESULTS
Project No. 20-7-148
SAMPLE LOCATION
NATURAL
MOISTURE
CONTENT
(%)
NATURAL
DRY
DENSITY
(pcf)
GRADATION
PERCENT
PASSING NO.
200 SIEVE
ATTERBERG LIMITS
UNCONFINED
COMPRESSIVE
STRENGTH
(psf)
SOIL TYPE
BORING
DEPTH
(ft)
GRAVEL
o
(/o)
SAND
o
(/o)
LIQUID LIMIT
(%)
PLASTIC
INDEX
(%)
1
21/2
9.8
107
21
Silty Sand
5
7.7
105
19
Silty Sand
15
6.8
30
36
34
Silty Sand and Gravel
20
9.5
102
51
Sandy Silt
25
3.0
126
33
Silty Sand with Gravel
30
3.0
30
34
36
Silty Sand and Gravel
40
3.2
121
48
Very Silty Sand
2
21/2
9.3
118
Silty Sand
5
6.2
111
Silty Sand
10
3.9
43
27
30
Silty Sandy Gravel
15 & 20
2.5
35
27
38
Silty Sand and Gravel
30
2.9
127
28
Silty Sandy Gravel
40
2.9
42
29
29
Silty Sandy Gravel
50
3.1
135
47
Very Silty Sand
60
3.7
125
51
Sandy Silt