HomeMy WebLinkAboutCDP 96-14; Marja Acres PCS Facility; Coastal Development Permit (CDP) (10)HETHERINGTON ENGINEERING, INC.
SOIL & FOUNDATION ENGINEERING • ENGINEERING GEOLOGY • HYDROGEOLOGY
July 17, 1996
Project No. 1519.1
Log No. 2345
J. M. Consulting Group
3530 Camino Del Rio North, Suite 101
San Diego, CA 92108
Attention: Ms. Cheryl M. Hacke
Subject: SUPPLEMENTAL RETAINING WALL PARAMETERS
Proposed Cox California PCS Station
SD154-Marja Acres
Carlsbad, California
References: 1. "Geotechnical Investigation, Proposed Cox
California PCS Station, SD154-Marja Acres,
Carlsbad, California," by Hetherington
Engineering, Inc., dated February 21, 1996.
2. "Supplemental Geotechnical Investigation,
Proposed Cox California PCS Station, SD154-
Marja Acres, Carlsbad, California," by
Hetherington Engineering, Inc., dated May 14,
1996.
Dear Ms. Hacke:
In accordance with the request of the project Structural Engineer,
we are providing the following supplemental soil parameters for
retaining walls at the subject site. Retaining walls free to
rotate (cantilevered walls) should be designed for an active
pressure of 70 pounds per cubic foot, equivalent fluid pressure,
for 1-1/2:1 (horizontal to vertical) sloping backfill consisting of
on-site soils derived from the bedrock material or imported
granular material. Walls restrained from movement at the top
should be designed for an additional uniform soils pressure of 8xH
pounds per square foot where H is the height of the wall in feet.
Any additional surcharge pressures behind the wall should be added
to these values.
5245 Avenida Encinas, Suite G • Carlsbad, CA 92008-4369 • (619) 931-1917 • Fax (619) 931-0545
32242 Paseo Adelanto, Suite C • San Juan Capistrano, CA 92675-3610 • (714) 487-9060 • Fax (714) 487-9116
SUPPLEMENTAL RETAINING WALL PARAMETERS
Project No. 1519.1
Log No. 2345
July 17, 1996
Page 2
This opportunity to be of service is appreciated. If you should
have any questions, please contact Danny Cohen at the Carlsbad
office.
Sincerely,
HETHERINGTQN EN£l.
DANNY
Civil
(expires 3/Geotechnical
(expire 3/
MDH;DC/sl
cc: Chung Song
Prime Structural Engineers
2614 Gianelli Lane
Escondido, CA 92025
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL INVESTIGATION
Proposed Cox California
PCS Station
SDl54-Marja Acres
Carlsbad, California
HETHERINGTOIM ENGINEERING, INC.
HETHERINGTON ENGINEERING, INC.
SOIL & FOUNDATION ENGINEERING • ENGINEERING GEOLOGY • HYDROGEOLOGY
February 21, 1996
Project No. 1519.1
Log No. 2142
J. M. Consulting Group
3430 Camino Del Rio North, Suite 101
San Diego, CA 92108
Attention: Ms. Cheryl M. Hacke
Subject: GEOTECHNICAL INVESTIGATION
Proposed Cox California PCS Station
SD154-Marja Acres
Carlsbad, California
Dear Ms. Hacke:
In accordance with your request, we have performed a geotechnical
investigation at the subject site. Our work was performed in
February 1996. The purpose of our investigation was to evaluate
soil and geologic conditions, and provide grading and foundation
recommendations for the proposed antenna and equipment storage area
sites. To assist with our investigation, we were provided with a
Site Plan, prepared by Gold Coast Surveying.
With the above in mind, our scope of work included the following:
o Research and review of available pertinent geologic
literature, maps, and plans (see References).
o Subsurface exploration consisting of two hollow-stem auger
borings and two hand-auger borings to obtain soil and bedrock
samples and observe subsurface conditions.
o Laboratory testing.
o Engineering and geologic analyses.
o Preparation of this report providing the results of our field
and laboratory work, analyses, and our conclusions and
recommendations.
SITE DESCRIPTION
The subject site consists of specified easements which are portions
of Marja Acres, an agricultural property located along the south
side of El Camino Real, approximately 1/2-mile southeast of
Tamarack Avenue, Carlsbad, California (see Location Map, Figure l).
5245 Avenida Encinas, Suite G • Carlsbad, CA 92008-4369 • (619) 931-1917 • Fax (619) 931-0545
32242 Paseo Adelanto, Suite C • San Juan Capistrano, CA 92675-3610 • (714) 487-9060 • Fax (714) 487-9116
GEOTECHNICAL INVESTIGATION
Project No. 1519.1
Log No. 2142
February 21, 1996
Page 2
Topographically, the site consists generally of relatively level
ground and a north facing fill over natural slope which descends
approximately 55 feet to a parking lot at the rear of a commercial
building.
PROPOSED DEVELOPMENT
Proposed construction consists of an equipment storage area (BTS)
and two separate antenna sites which will support three antennas
each.
SUBSURFACE EXPLORATION
Subsurface conditions were explored by excavating two truck-mounted
hollow-stem auger borings to depths of 31 feet and two hand-auger
borings to depths of 3 1/2 and 4 feet. The approximate locations
of the borings are shown on the attached Plot Plan, Figure 2.
The subsurface exploration was supervised by an engineer from this
office, who visually classified the soil and bedrock materials, and
obtained bulk and undisturbed samples for laboratory testing. The
soils were visually classified according to the Unified Soil
Classification System. Classifications are shown on the Boring
Logs, Figures 3 through 5.
LABORATORY TESTING
Laboratory testing was performed on samples obtained during the
subsurface exploration. Tests performed consisted of the
following:
o Dry Density and Moisture Content (ASTM: D 2216)
o Expansion Index (ASTM: D 4829)
o Direct Shear (ASTM: D 3080)
o Particle Size Analysis of Soils (ASTM: D 422)
Results of the dry density and moisture content determinations are
presented on the Boring Logs, Figures 3 through 5. The remaining
laboratory test results are presented on Figure 6 through 9.
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL INVESTIGATION
Project No. 1519.1
Log No. 2142
February 21, 1996
Page 3
SOIL AND GEOLOGIC CONDITIONS
1. Geologic Setting
The subject site lies within a stretch of coastal hills that
are contained within the coastal plain region of northern San
Diego County, California. These coastal hills are
characterized by numerous marine terraces of Pleistocene age
that have been established and deposited above wave-cut
platforms of the underlying Eocene bedrock and extend from
inland areas of higher elevation and descend generally west-
southwest in a "stairstep" fashion down to the present day
coastline. The site area is contained within the south-
central portion of the USGS San Luis Key 7-1/2 minute
quadrangle.
The proposed construction site is underlain by surficial soils
consisting of undocumented fill soils and colluvium, which are
in turn underlain by Pleistocene age terrace deposits and
sedimentary bedrock deposits of the Eocene Santiago Formation.
Structurally, bedding within the terrace deposits is
considered to be essentially massive, while bedding within the
Santiago Formation for the general site vicinity reportedly
dips around 10 to 15 degrees in a northwest to southwest
direction (see References). Active or potentially active
fault zones within the general site region include the
offshore extension of the Rose Canyon, Coronado Banks, and the
inland Elsinore, which are located approximately 6 miles
southwest, 21-1/2 miles southwest, and 23 miles northeast from
the site respectively.
A brief description of the geologic units observed within the
site follows.
a. Fill
Undocumented fill soils within the proposed construction
site consist of moist, soft to firm, dark brown silty to
slightly sandy clay. The thickness of this material was
approximately 4 feet in B-l and the fill is not
considered suitable for support of the proposed antennas
or equipment storage area in its existing state.
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL INVESTIGATION
Project No. 1519.1
Log No. 2142
February 21, 1996
Page 4
b. Colluvium
Colluvium, ranging in thickness from approximately 3 feet
in B-l to 6 feet in B-2, consists generally of highly
expansive, very moist, firm, brown to dark brown silty to
sandy clay. The colluvium is not considered suitable for
support of the proposed antennas or equipment storage
area in its existing state.
c. Terrace Deposits
Pleistocene age marine and non-marine terrace deposits
underlying the colluvium in all the borings consists
generally of moist to very moist, medium dense to dense
orange brown to gray clayey to silty sands and moist to
very moist, firm to stiff, olive gray to orange brown
clayey silt and silty clay. The geologic contact between
the terrace deposits and underlying Santiago Formation
appears to be at an elevation of approximately 87 to 88
feet above MSL.
d. Santiago Formation
Sedimentary bedrock deposits of the Eocene Santiago
Formation encountered beneath the site consist generally
of moist, medium dense to dense and stiff, olive gray to
olive green to orange brown sandstone, siltstone, and
claystone.
3. Groundwater
No groundwater was observed in the borings during our
investigation. It should be noted, however, that fluctuations
in the amount and level of groundwater may occur due to
variations in rainfall, irrigation, and other factors which
may not have been evident at the time of our field
investigation.
SEISMICITY
The site is within the seismically active southern California
region. There are, however, no known active or potentially active
faults located within or adjacent to the site. Active and
potentially active fault zones within the general site region
include the offshore extension of the Rose Canyon, offshore
Coronado Banks, and the Elsinore, which are located approximately
6 miles southwest, 21-1/2 miles southwest, and 23 miles northeast
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL INVESTIGATION
Project No. 1519.1
Log No. 2142
February 21, 1996
Page 5
from the site respectively. Strong ground motion could also be
expected from earthquakes occurring along the San Jacinto and San
Andreas fault zones which lie northeast of the site at
distances of approximately 47 miles and 70 miles, respectively.
The San Clemente fault, which lies approximately 59-1/2 miles
southwest of the site, as well as numerous other offshore faults,
could also cause strong ground motion.
Seismic risks on-site are limited to ground shaking during seismic
events on active faults in the region. The following table lists
the known active or potentially active faults which would have the
greatest impact on the site.
Maximum Probable
Earthquake Estimate Bedrock Acceleration
Fault (Moment Magnitude) Peak Repeatable
Rose Canyon 6.5 0.40g 0.26g
(6 miles SW)
Coronado Banks 6.0 O.lOg O.lOg
(21-1/2 miles SW)
Elsinore 7.0 0.20g 0.20g
(23 miles NE)
SEISMIC EFFECTS
1. Ground Acceleration
The most significant probable earthquake to effect the site,
would be a 6.5 magnitude earthquake on the Rose Canyon fault.
Potentially, repeatable horizontal ground accelerations on the
order of 0.26g are possible with a duration of strong ground
motion exceeding 25 seconds. Peak (instantaneous)
accelerations would be higher.
2. Liquefaction
Liquefaction is not a potential site hazard due to the dense
underlying bedrock and lack of shallow groundwater.
3. Landsliding
Seismically induced landsliding is not considered a site
hazard.
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL INVESTIGATION
Project No. 1519.1
Log No. 2142
February 21, 1996
Page 6
4. Tsunamis
Due to the relatively high elevation of the site and the
distance of the site inland from the shoreline, seismically
generated ocean waves are not considered a site hazard.
CONCLUSIONS AND RECOMMENDATIONS
1. General
The proposed development is feasible from a geotechnical
standpoint. Grading and foundation plans should take into
account the appropriate geotechnical features of the site.
2. Slope Stability
No geologic conditions are known which would adversely affect
gross slope stability. Slope stability analysis indicates a
factor of safety of at least 1.5 for gross slope stability.
The upper approximately 3 feet of the natural slope in the
area of the proposed antennas is considered surficially
unstable. Foundation recommendations will mitigate the
possible adverse affects of surficial slope instability.
3. Site Grading
Prior to grading, the site should be cleared of existing
debris and stripped of vegetation. The resulting debris
should be disposed of off-site. Any underground structures or
tanks should be removed in accordance with local regulations.
Holes resulting from the removal of buried obstructions, which
extend below finished site grades, should be replaced with
compacted fill.
Fill should be compacted by mechanical means in uniform
horizontal lifts of 6 to 8-inches in thickness. All fill
should be compacted to a minimum relative compaction of 90
percent based upon ASTM: D 1557-91A. Soils used as compacted
fill should be placed at about optimum moisture content. Rock
fragments over 6-inches in dimension and other perishable or
unsuitable materials should be excluded from the fill. All
grading and compaction should be observed and tested as
necessary by the Geotechnical Engineer.
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL INVESTIGATION
Project No. 1519.1
Log No. 2142
February 21, 1996
Page 7
4. Foundation Recommendations
a. Equipment Storage Area
The proposed site for the equipment storage area is not
suitable to support the structure in its present
condition due to the existence of undocumented fill
soils and colluvium. The existing fill slope evidences
tension cracking along the top of the slope. Two
alternates are presented to construct the proposed
equipment storage area at this location.
Alternative A: Remove and recompact the existing
undocumented fill soils and colluvium. Removals should
extend down to the underlying terrace deposits and should
extend to at least 5 feet outside the limits of the
proposed equipment storage area. Fill should be placed
in accordance with the site grading recommendations.
Removals on the order of 6 to 8 feet below existing grade
are anticipated. Actual removal depths should be
determined by the Geotechnical Engineer based on
conditions exposed during grading.
If Alternative A is utilized, foundations in the
equipment storage area may consist of conventional
continuous footings founded at least 24 inches into
compacted fill. Continuous footings should be at least
12 inches wide and reinforced with a minimum of 2 - #5
bars top and bottom. Footings located on or adjacent to
slopes.should be extended to sufficient depth to provide
at least 10 feet of horizontal distance between the
footing and the slope face.
Footings bearing as recommended may be designed for a
dead plus live load bearing value of 2,000 pounds per
square foot. This value may be increased by one-third
for loads including wind or seismic forces. A lateral
bearing value of 200 pounds per square foot per foot of
depth and a coefficient of friction between foundation
soil and concrete of 0.35 may be assumed. These values
assume that footings will be poured neat against the
foundation soils. Footing excavations should be observed
by the Geotechnical Engineer to verify that they are
founded in suitable bearing materials.
Slabs-on-grade should be 6-inches thick and reinforced
with a minimum of #4 bars placed on 12-inch centers in
both directions and the reinforcement should be doweled
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL INVESTIGATION
Project No. 1519.1
Log No. 2142
February 21, 1996
Page 8
into the footings. Reinforcement bars should be placed
on chairs so that they are at mid-point of slab.
Additional footing and slab reinforcement may be required
by the Structural Engineer.
Alternative B: The equipment storage area may be founded
on drilled piers designed by the Structural Engineer in
accordance with the recommendations that follow for the
antenna foundations.
b. Antennas
The antennas located on the slope should be supported on
drilled piers founded in the underlying terrace deposits/
bedrock. The drilled piers should be designed to resist
lateral earth loads of 65 pounds per cubic foot
(equivalent fluid pressure) in the upper 4 feet for the
antennas and 8 feet for the equipment storage structure
(Alternate B) . Lateral loads should be applied over
three pier diameters. Lateral loads may be resisted by
a passive pressure of 200 pounds per square foot per foot
of depth in terrace deposits/bedrock. The passive
pressure may be calculated over two pier diameters.
Drilled piers should extend at least 5 feet into the
terrace deposits/bedrock and have a minimum diameter of
24-inches. Drilled piers may be designed for a dead plus
live load end bearing capacity of 4000 pounds per square
foot. A skin friction value of 200 pounds per square
foot may be assumed in terrace deposits/bedrock.
Foundation excavations should be observed by the
Geotechnical Engineer prior to placement of reinforcement
and concrete.
4. Grading and Foundation Plan Review
Final grading and foundation plans should be reviewed by the
Geotechnical Consultant to confirm conformance with the
recommendations presented herein or to modify the recommen-
dations as necessary.
LIMITATIONS
The analyses, conclusions and recommendations contained in this
report are based on site conditions as they existed at the time of
our investigation and further assume the excavations to be
representative of the subsurface conditions throughout the site.
If different subsurface conditions from those encountered during
HETHERINGTOIM ENGINEERING, INC.
GEOTECHNICAL INVESTIGATION
Project No. 1519.1
Log No. 2142
February 21, 1996
Page 9
our exploration are observed or appear to be present in
excavations, the Geotechnical Engineer should be promptly notified
for review and reconsideration of recommendations.
This opportunity to be of service is sincerely appreciated. If you
have any questions, please call Danny Cohen at the Carlsbad office.
Sincerely,
HETHERING , INC.
(expire 3/31/96
Cohen
1 Engineer 4
xpires 3/31/91
MDH;DC;BAB/sl
andon A. Boka
egistered Geologist
Certified Engineerin
(expires 3/31
HETHERINGTON ENGINEERING, INC.
REFERENCES
Aerial Photographs, Flight GS-VBTA, photos 143 and 144, May 3,
1967.
City of Carlsbad, Geologic and Seismic Safety Element, dated March
1975.
Eisenberg, Leonard I., 1983, Pleistocene Faults and marine
terraces, Northern San Diego County, In "On the Manner of
Deposition of the Eocene Strata in Northern San Diego County," San
Diego Association of Geologists, Edited by Patrick L. Abbott, 1985.
Jennings, C.W. 1992, Preliminary Fault Activity Map of California,
California Division of Mines and Geology Open-File Report 92-03.
Kennedy, Michael P., 1975, Geology of the San Diego Metropolitan
Area, California, Section A (Western San Diego Metropolitan Area),
California Division of Mines and Geology, Bulletin 200.
Ploessel and Slossen, 1974, Repeatable High Ground Accelerations
from Earthquakes, EERI Nomograph.
Seed and Idriss, 1982, Ground Motion and Soil Liquefaction During
Earthquakes, EERI Nomograph.
Weber, Harold F., Jr., 1982, Recent Slope Failures, Ancient
Landslides, and Related Geology of the North-Central Coastal Area,
San Diego County, California, California Divisions of Mines and
Geology, Open-File Report 82-12LA.
HETHERIN6TON ENGINEERING, INC.
L BASE MAP: C.D.M.G. SAN LUIS REY 7-1/2 MINUTE QUADRANGLE
NORTH
SCALE: 1'=2000'
LOCATION MAP
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
JMCG/COX-SD 154
Marja Acres, Carlsbad
PROJECT NO. 1519.1 J FIGURE NO.1
POSITION B
(ON BANK)
EL-87.3'
POSITION A
(RD EDGE)
EL-105.2'
"°*TH
LEGEND
APPROXIMATE LOCATION OF
BORING
B-4
APPROXIMATE SCALE: 1'=30'
PLOT PLAN
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
JMCG/COX-SD 154
Marja Acres, Carlsbad
PROJECT NO. 1519.1 I FIGURE NO.2
DRILLING COMPANY: F & C Drilling RIG: B-61 DATE: 2/15/96
BORING DIAMETER: 8" DRIVE WEIGHT: 140 IbS. DROP: 30" ELEVATION: 105 t
j DEPTH (FEET)u.u
.0
10.0—
15.0—
20.0—
25.0—
30.0 —
op n BULK SAMPLEDRIVE SAMPLEBLOWS/6 "X,
• 32
xU 25
H 44
• 34
• 38LD
• 44
• 52
I 41
• 57
• 41
N49 I DRY DENSITY(pcf)106
99
107
98
88
99
105
111
107
102
95 MOISTURECONTENT O/O17.2
25.3
20.7
26.0
33.7
22.7
17.0
14.8
21.0
24.7
26.4
CO ^CO •<C CO
do'
ri°i
83
CL
CL
BORING NO. B-1
SOIL DESCRIPTION
FILL: Dark
to firm
@ 3': be
brown silty and slightly sandy clay, moist, soft
comes firm
CQLLUVIUM: Brown silty to sandy clay, very moist, firm
TERRACE DEPOSITS: Oranae brown sliahtlv clayey medium to
coarse sand, moist, medium dense
Gray to gray brown silty and sandy clay with some caliche
veins, moist to very moist, firm to stiff
@8.5': Olive gray to gray brown silty fine sand /
Mottled olive gray and orange brown clayey silt and silty
clay with scattered caliche blebs, very moist, firm to stiff
@13': Some slight porosity
Orange brown to gray silty fine sand, moist, dense
BEDROCKfSantlago Formation): Gray to orange brown clayey
and silty fine sandstone, moist, medium dense to dense
Olive grt
siltstone
hard car
@ 24': Z
clayey s
ly with some orange brown clayey and fine sandy
moist to very moist, stiff, scattered inclusions
Donate
ones of brown gray clay and orange and gray slightly
and, moist, firm and dense, some porosity
Olive green with some orange brown silty claystone, moist
to very moist, stiff, fractured
@25': Scattered inclusions of hard carbonate
Total Depth = 31 Feet
No Groundwater
No Caving
ou.U
-
BORING LOG
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
JMCG/COX-SD154
Marja Acres, Carlsbad
PROJECT NO. 1519.1 FIGURE NO. 3
DRILLING COMPANY: F & C Drilling RIG: B-61 DATE: 2/15/96
BORING DIAMETER: 8" DRIVE WEIGHT: 140 IbS. DROP: 30" ELEVATION: 101 +I DEPTH (FEET)u.u
.0
10.0
15.0—
20.0—
25.0—
JO.O
IK n BULK SAMPLExj
XI UKJ.Vt £>Hnri_tBLOWS/6"1 24
1 21
• 44
XB 38
1
x
ou.U
1 36
| 38
1 46
I 58
1 45
I 61
|DRY DENSITY(pcf)109
92
122
114
103
108
104
97
101
110 MOISTURECONTENT (*)18.7
28.3
8.3
12.4
9.1
20.6
21.2
27.2
24.0
10.4
CO ~
CO •<C COdo
_l COH -0 Z>CO ^
CL
BORING NO. B-2
SOIL DESCRIPTION
COLLLMUM: Dark brown to gray brown silty clay, very moist,
firm
TERRACE DEPOSITS: Light gray fine to coarse sand with
some gravel and olive gray slightly clayey to silty fine
to medium sand, moist, medium dense, some slight porosity
Dark gray to black to brown medium to coarse sand with
some gravel, moist, medium dense to dense
BEDROCK(Santiaqo Formation): Olive brown to olive gray clayey
and silty fine sandstone, moist, medium dense to dense
@ 18': Thin lenses of olive gray to white fine to coarse
sandstone and silty fine sandstone, moist, medium dense
to dense
Olive green with some orange brown fine sandy to silty
claystone, moist to very moist, stiff, fractured
@ 26': lenses of orange brown coarse sand
Olive gray with some orange brown silty fine sandstone,
moist, dense
Total Depth = 31 Feet
No Groundwater
No Caving
—
;
BORING LOG
JMCG/COX-SD154HETHERINGTON ENGINEERING, INC. Marja Acres, Carlsbad
GEOTECHNICAL CONSULTANTS PROJECT NO. 1519.1 FIGURE NO. 4
DRILLING COMPANY:RIG: Hand-Auger DATE: 2/15/96
BORING DIAMETER:3"DRIVE WEIGHT:DROP:
UJLUU_
Q.
UJQ
~0.0
UJ
Q.
cn
v
CD
OOu_
to
CQ
05
LUQ
o:a
Oa
.X
UJ
\- UlW (-H ZO OE U
in ^en •<c o>
u
V)
SOIL DESCRIPTION
BORING NO. B-3 ELEVATION: 93 t
CL COLLUVIUM: Dark brown slightly sandy clay to clay,
moist, firm
5.0—
TERRACE DEPOSITS: Tan brown to orange brown fine to medium
sand, moist, dense
Total Depth = 4 Feet
No Groundwater
No Caving
10.0—
15.0-
BORING NO. B-4 ELEVATION: 92 t
-0.0
—
^^
CL COLLUVIUM: Dark brown slightly sandy clay to clay,
moist, firm
- TERRACE DEPOSITS' Orannp hrnwn <?anrlv <?ilt tn siltv «;anri
moist, firm/dense /
Total Depth = 3.5 Feet
No Groundwater
No Caving
-
-
15.0-
BORING LOG
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
JMCG/COX-SD154
Marja Acres, Carlsbad
PROJECT NO. 1519.1 FIGURE NO.
EXPANSION
(ASTM: D 4829)
Sample
Location
B-l e 1'
B-2 6 2'
initial
Moisture
(%)
13.9
11.8
Compacted
Dry
Density
(pcf)
93
102
Final
Moisture
<%)
34.6
28.5
Volumetric
Swell
17.1
13.9
Expansion
Index
171
139
Expansion
Potential
Very High
Very High
DIRECT SHEAR
(ASTM: D 3080)
Sample Location
B-l @ 6'
B-l @ 10'
B-2 @ 4'
B-2 @ 18'
Cohesion
(psf)
975
200
100
400
Internal Angle of
Friction (')
22
27
27
34
Remarks
Undisturbed ,
consolidated, saturated,
drained.
Undisturbed,
consolidated, saturated,
drained.
Undisturbed,
consolidated, saturated,
drained.
Undisturbed,
consolidated, saturated,
drained.
Figure 6
Log No. 2142
Project No. 1519.1
100
U.S. STANDARD SIEVE SIZES
3 1-1/2 3/4 3/8 4 8 1620304050 100 200
HYDROMETER
100 1 0.1
GRAIN SIZE (mm)
0.01
100
0.001
COBBLES GRAVEL
Coarse Fine
SAND
Coarse Medium Rne SILT and CLAY
SYMBOL
O
SAMPLE LOCATION
B-1 at 1.0
% PASSING
NO. 4 SIEVE
100
% PASSING
NO. 200 SIEVE
82
% FINER
2 MICRONS
48
UNIFIED SOIL
CLASSIFICATION
GRADATION TEST RESULTS
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
JMCG/COX-SD154
Marja Acres, Carlsbad
PROJECT NO. 1519.1 FIGURE NO.
100
U.S. STANDARD SIEVE SIZES
3 1-1/2 3/4 3/8 4 8 1620304050 100 200
HYDROMETER
100 10 1 0.1
GRAIN SIZE (mm)
0.01
100
10
0.001
COBBLES
GRAVEL
Coarse Fine
SAND
Coarse Medium Fine SILT and CLAY
SYMBOL
O
SAMPLE LOCATION
B-1 at 4.0
% PASSING
NO. 4 SIEVE
100
% PASSING
NO. 200 SIEVE
75 -
% FINER
2 MICRONS
47
UNIFIED SOIL
CLASSIFICATION
GRADATION TEST RESULTS
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
JMCG/COX-SD154
Marja Acres, Carlsbad
PROJECT NO. 1519.1 FIGURE NO. 8
100
U.S. STANDARD SIEVE SIZES
3 1-1/2 3/4 3/8 4 8 16 20 30 40 50 100 200
HYDROMETER
100 1 0.1
GRAIN SIZE (mm)
0.01
100
0.001
COBBLES
GRAVEL
Coarse Rne
SAND
Coarse Medium Rne
SILT and CLAY
SYMBOL
0
SAMPLE LOCATION
B-2 at 4.0
% PASSING
NO. 4 SIEVE
100
% PASSING
NO. 200 SIEVE
77
% FINER
2 MICRONS
43
UNIFIED SOIL
CLASSIFICATION
GRADATION TEST RESULTS
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
JMCG/COX-SD154
Marja Acres, Carlsbad
PROJECT NO. 1 51 9.1 FIGURE NO. 9