HomeMy WebLinkAboutSP 182; ELM GARDEN OFFICES; SOIL INVESTIGATION; 1982-08-09I ep
REPORT OF SOIL INVESTIGATION 0
jI / Elm Garden Offices
I
El Camino Real and Elm Avenue
( Carlsbad, California
JOB NO. 82-2203
09 August 1982
I
I
prepared for
I . Mr. Bill Seargeant
LUSARI CONSTRUCTION COMPANY
I
I
I 0
H
I 0 •1
I
I
. prepared by
GEOTECHNICAL EXPLORATION, INC.
8145 Ronson Road, Suite H
I San Diego, CA 92111
I BIN
1 . .
1 0 .0 1
,iI_i1'_CID GEOTECHNICAL EXPLORATION, INC.
SOIL & FOUNDATION ENGINEERING
GROUNDWATER • GEOPHYSICS • ENGINEERING GEOLOGY
09 August 1982
I Mr. Bill Seargeant JOB NO. 82-2203
LUSARDI CONSTRUCTION COMPANY
1570 Linda Vista Drive
San Marcos, CA 92069
Subject: REPORT OF SOIL INVESTIGATION
I Elm Garden Offices
El Camino Real and Elm Avenue
Carlsbad, California
I Dear Mr. Seargeant:
In accordance with your request, Ceotechnlcal Exploration, Inc. has performed an
I investigation of the surface and subsurface soil conditions at the location of the
subject proposed office complex. The field work was performed on July 27, 1982 by
our Field Engineer. I
I It is our understanding that the site is immediately being developed to receive an
office structure in the southern portion of the property. The structure is to be a
I
maximum of three stories in height and will be of wood-frame construction, utilizing
conventional, continuous foundations or spread footings. Proposed dveIopment for
the remaining portions ot the property had not been finalized at the time of our
Investigation.
I Our investigation revealed the site to be underlain with dense, formational sand and
siltstones. Moderately to highfr expansive topsoils are present on the site. Moderate
I , to well-compacted fill soils overlie large portions of the site. Additionally, an ancient
landslide was discovered on the site. The landslide appears to be stabilized as the
site exists, and should remain stable if the conclusions and recommendations
I
presented in this report are implemented during site prepartation.
This opportunity to be of service is sincerely appreciated. Should you have any ques-
tions concerning the following report, please do not hesitate to contact us. Refer-
ence to our Job No. 82-2203 will expedite response to your inquiries.
Respectfully submitted,
I GEOTECHNICAL EXPLORATION, INC.
I G
I
Raym'J. Scara7lla,'Vice President
RJS/pj
Enclosures
I 8145 RONSON ROAD, SUITE H • SAN DIEGO, CALIFORNIA ?2111-208I ° (7 14) 560-0428
LI
REPORT OF SOIL INVESTIGATION
Elm Garden Offices
El Camino Real and Elm Avenue
Carlsbad, California
108 NO. 82-2203
The following report present the findings and recommendations of GEOTEC1PIICAL
EXPLOR4TICN, INC. for 'the subject project.
SCOPE OF WORK
It is ojrunderstanding, based on communications with Mr. Seargeant of Lusardi
construrt10n1 that the southern portion of the site is intended for the construction of
an office LuiIding to be a maximum of three stories in height. The development of the
site requires a grading operation which will generate a cut slope (to be a maximum of
40 feet in1 height) alongL the east property line. Retaining walls are planned to be
placed at the,toe of this ;skpe, as well as at the toe of the existing on-site cut slope.
Development plans for the remaining portions of the site had not been finalized at the
time of oj'r investigation, however, the existing level portions of the property (to the
north) will! receive minimal future grading. With the aboveIn mind, the Scope of Work
is briefly utlined as follows:
4
Identify and classify the surface and subsurface soils to depths, in conformance
the Unified Soil Classification System (refer to Appendix A).
Determine the allowable bearing pressures for the natural ground and the soils
I to be used in compacted fill, based on their shear-strength characteristics and
our experience with the soils.
I H H
Recmmend treatment for any expansive soils that, if left in place and
unmodified, could result in eventual damages to the proposed structure.
Predict the settlement of the natural-ground soils, as well as existing,
I compacted fill soils under the proposed structural loads.
H
I
Elm Garden Offices Job No. 82-t2jj
09 August 1982 Page
I 5. Determine the location and magnitude of, ancient landslides occurring on the
subject site which may affect the development of the site.
6. Provide design information concerning recommendations for slope ratios for
I proposed natural ground cut slopes.
SITE
The property is legally described as: A portion of Lot J of the Rancho Agua HedIon,
I Map No'. 832, in the City of Carlsbad, County of San Diego, State of California.
The site, consisting of approximately 6.9 acres, is located at the northeast corner of
the Elm Avenue and El Camino Real intersection, in the City of Carlsbad, California.
I ' The property is bordered on the east by apparently natural hillside terrain; and on the
north by a graded, vacant, lot.
There were no existing structures on the site at the time of our investigation. Vegeta-
tionon the site consists primarily of a light tol heavy growth of grasses 'and weeds.
The southern portion of the 'property is comprised of natural hillside terrain, sloping
moderately to the west and northwest.
A cut slope (a. maximam of 20 feet in height) has been placed along the south and
southwest 'portion of the west property lines 1 (see Figure No. I) during the past
grading operation. The northern portions of the property have been graded to a
relatively level condition by the placement of fill soils. Elevations on the site range
from 79 feet above mean sea level (MSL) to 168 feet MSL.
1 FIELD
Ten test trenches were placed on the site, specifically in areas where structures and
improvements will be located and where unique soils and/or geologic conditions were
expected. The excavations were located In the field by referring to an undated Grading
Plan and Topographic Map dated August 18, 1982, both prepared by ,Brian Smith
H H E r--~, dD
Elm Garden Offices Job No. 82-2203
09 August 1982 Page 3
Engineers, Inc. The excavations were visually inspected by our Field Engineer, and
samples, were taken of the predominant soils throughout the field operation. Test
trench logs have been prepared on the basis of our inspection and the results have
been summarized on Figure No. II. The preddminant soils have been classified in
conformance with the Unified Soil Classification System (refer to Appendix A).
SOILSj
The natural ground topsoils overlying the site range from two to five feet In thickness
and consist of firm, dark-gray to black, sandy clays. The topsoils are moderately to
highly expansive as measured by the County of San Diego Test f"or Expansive Soils.
I. I.
4
The topsoils are underlain, with relatively dense, formational materials. The
encountered formation consists of Interbedded, ian to white, non-expanshe, sllty,'flne
to medium sands and brown to green-gray, moderately to highly fractured slltstone.
The siltstones are moderately expansive.
Compacted fill soils have been placed over the northern two-thirds of the property,
and apparently range to a maximum of 20 feet in, thickness. These fills were tested for
compaction (during the actual grading operation) by Southern California Testing
LabOratories. To verify the degree of compaction of the fills during this investigation,
in-place density tests were taken in the fills at scattered, random locations .1
The1 results ot our density tests further indicate that the fills are adequately
compacted. The fills are comprised of a mixture of the above described soils and are
low to moderately expansive.
The formational unit encountered underlying the site (described previously) Is the
Santiago Formation, which is Eocene in age. Because of the massive nature of the
formational materials and due to some landsliding, an accurate attitude of the
formational materials could, not be obtained.
1.
I
I Elm Garden.Offices Job No. 82-ZZO
August 1982
i
IA màderately-sized, ancient landslide wag encountered in this formational unit at the
southern portion of the property. A secondary shear zone for this landslide was
encountered in our test 'excavations. The attitude of the shear zone is strike N10°W,
I dip.13°to14°W.
I Additionally, judging from the appearance of the surface topography and observations
in test tench #5, it appears a smaller, ancient landslide is located north of and
t I .
I adjacent to the larger landslide (see Figure No. I for the approximate location and
projected aerial extent ot these landslides).
I '1 I The toe of •the larger landslide would appear to, project out into the areaof El Cnalno
Real, which -was a canyon bottom prior to the placement of fill soils. The placement
I of these fills appear to 1have stabilized the movement of, the landslide's rimary shear
zone by producing a buttress effect. The smaller landslide has been stabilized by the
I
I placement of the fill pad on the subject site.
I Sine some of the materials in the proposed cut slope area are highly fractured, as
well as dipping out of slope, at places, it is recommended a stability fill bépláced
I
against the proposed cut slope.
lIthãiid c0n strüt'ar A key' a minimum
I
, of five feet in depth shall be excavated into the firm, natural ground soils or compact-
ed till soils at the base of the stability till (see Figure No. IV for a tyIcalsection view
I
of the stability fill). The key" shall be inspcted by our Engineering Geologist and
deeened if so required by the Engineering Geologist, prior .to filling and compacting.
I It is recommended the stability fill be 'comprised primarily of on-'site, white, tine to
medium sands. The surface of the stability fill must be compacted such that when
I tested at a, horizontal distance of 12 inches from the face of the fill slope, 85 percent
of MaxirntiM Dry Density is obtained.
I_____________ I .. U
I
fiiideThtioriieproposedcut-s lope-and--slope lity.JULperatirriniist betired'so
JhgradungJscompletedwel lbefore'theantucupatedrau fly season. 76-fthernS)
_L - stand for-any more than a 72--h-ourperiod-,.
dD
I,
••
• •
I.: •
,- ••
I
H •'.
Elm Garden Offices Job No. 82-2203
1 09 August 1982 Page 5
It is, recommended that a horizontal drain be placed at the base and at the rear of the
I "key. The drain shall consist of a tour-inch diameter, plastic, perforated pipe
surrounded by at least three (3) cubic feet of gravel. To prevent clogging, the system
shall be wrapped in an approved filter-cloth material such as Mirafi 140.
An additional horizintal drain shall be placed at an elevation of approximately 20 feet
I .
above the bottom of the key' and shall be of the same construction. The drains
shall have a minimum fall (to the south) of one percent and empty Into an approved
I drainage system. The drain pipes shall be of sufficient strength to withstand
anticipated soil-surcharge loads.
Although no water seeps were observed during' the course of our investigation, the
I
proposed drain system would tend to alleviate any future hydrostatic pressure build-up
on the stability fill that could occur from the existing development to the east of the
property.
GROUND WATER
I . No ground water problems were encountered during the course of our field investi-
gation and We do not expect significant problms to develop in the future--if the
'property is developed as 'presently designed. It should'be kept in mind, however, that
I . any required grading operations may change surface drainage patterns and/or reduce
permeabilities due to the densification of compacted soils. Such changes of surface
and subsurface hydrologic conditions, plus irrigation of landscaping or significant
I increases in rainfall, may result in the appearance of minor amounts of surface or
near-surface water at locations where none existed previously. The damage from such
water is expected to be minor and cosmetic in nature, if good positive drainage Is Im-
plemented at the completion of construction. Corrective action should be taken on a
I site-specific basis if, and when, it becomes necessary.
Elm Garden Offices Job No. 82-2203
09 August 1982 Page 6
LABORATORY TESTS
Laboratory tests were performed on the disturbed and undisturbed soil samples in
order to determine their'plysical and mechanical properties and their ability to sup-
port the proposed structure The The following tests were conducted on the sampled
soils:
Moisture Content
Density Determinations:
Mchanical Analysis
Expansion Tests
Direct Shear Tests 4
Consolidation Tests
The moisture and density determination relationhip on undisturbed soil samples gives
qualitative information regarding the soil strength characteristics and soil conditions to
be anticipated during the future grading operation.
The mechanical analysis was performed on selected soils according to A.S.T.M.
422-52T. The mechanical analysis was used toiaid in the classification of the soils
according to the Unified Soil Classification System.
Expansion values were determined from the County of San Diego Test Method, for
Expansive Soils. Expansive soils are classified as 'follows:
o to 3 percent Low or Considered 'Nonexpansive'
3 to 6 percent Medium
6 to 12 percent High
Above 12 percent Very: High
According to the County of San Diego Test for Expansive Soils, swells of less than 3
percent are classified as nonexpansive soils.
Elm Garden. Offices Job No. 82-2203
09 August 1982 Page 7.
Direct shear tests were performed upon undisturbed and remolded bulk samples in
order to determine the soil strength and supporting capacity for the natural-ground
soils and these same soils used or to be used in the compacted fill. The shear tests
were made with a constant strain direct shear machine. Specimens to be tested were
saturated and then sheared under various normal, loads without appreciable drainage of
the samples. . .
Consolidation Tests were performed on undisturbednatural-ground soils and remolded
soils used or to be used in the compacted fills. The soils are contained In 1-Inch high
brass rings and loaded into a consolidometek The specimens are subjected to
increased loads and the resulting consolidations noted. The consolidation, tests aid in
determining anticipated settlements of the natural ground under the proposed building
loads. I ,
CONCLUSIONS AND RECOMMENDATIONS
The following conclusions and recommendations are based' upon the practical field
investigations conducted by our firm, and resulting laboratory tests, in conjunction
with our knowledge and experience with the soils in the Carlsbad area.
1. The natural-ground topsoils on this site c.nsist of two to five feet of dark-gray
to black, sandy clays. The clays were tested and found to possess 5.0 to 7.0
percent swell, as measured by the County of San Diego Test for Expansive Soils.
The topsoils are underlain by dense, formational materials consisting of brown,
highly fractured ' siltstones possessing 3.0 to 3.5 percent swell and
non-expansive, white, fine to medium sands. Moderately to well-compacted fill
soils overlie the lower elevations of the site. These fills are comprised of a
mixture of the above materials and obtain a maximum thickness of 20 feet. The
fills are low to moderately expansive. .
Elm Garden Offices Job No. 82-
09 August 1982 Page
2. Unless' properly dealt with, the moderately to highly expansive characteristics of
the above described soils can cause significant damage to the proposed struc-
ture and associated improvements. In order to reduce significantly the
potential for such damage, one or more of the recommendations herein must be
followed:
2.1.. The proposed. structure (as located by the undated Grading Plan by Brian
Smith Engineers, Inc.) will be placed at an elevation of approximately 138
feet MSL. The building pad resulting from the cut and fill grading
operation should expose the nónexpansive, white,: fine to medium sands
at the bearing levels. Thus, expansive soil design criterion are not
expected to be needed for this particular structure. Any expansive soils
(such as the black topsoils or brown siltstones) which are excavated from
the cutting operation should be placed in filled ground areas a minimum
of five feet outside perimeter foundations and preferably, three feet below
proposed finish grade elevations.
In the event an expansive lense is encountered (at the bearing level)
during the excavating operation, expansive soil recommendations or
alternatives will be issued at that time (such as those described in
Recommendation 2.2 and 2.3).
2.2 The soils comprising the existing,
, graded fill pad are low to moderately
expansive. If the planned structure and improvements are to be
constructed using standard, non-expansive-soils design criteria, this area
shall be prepared as follows:
2.2.1 The moderately expansive soils shall be removed from all
structural areas to a minimum distance of five feet outside perimeter
footings. The clay soils shall be removed to a minimum depth of three
feet below the proposed, rough, finish-grade elevations.
Elm Garden Offices Job No. 82-2203
09 August 1982 i Page 9
2.2.2 Excavated areas shall be backfilled with nonexpansive soils
(such as or-site, white, fine to medium sands or soils obtained from an
approved off-site borrow pit). The non-expansive select materials must
be placed and compacted to at least 90 percent of Maximum Dry Density,
in accordance with the requirements of the County of San Diego Grading
Ordinance. Upon satisfactory completion of the backfilling operation,
continuous and spread footings may be designed, in accordance with the
soil-bearing value assigned to the compacted nonexpansive fill materials.
The continious and spread footings shall have a minimum width of 12
inches and extend a minimum depth of 12 inches into the compacted fill
soils for single-story structures.
2.2.3 Areas receiving improvements, such as patios, sidewalks,
A.C. pavement (parking areas), et cetera, shall be underlain' by at least
four inches of compacted fill materials, such as that used in the
backfilling operations for building locations.
2.3 if it is intended to construct the proposed structure and improvements
on the moderately expansive clay soils without preparation of the site (as
described irju Recommendation No. 2.2.1), the following recommendations
become applicable:
2.3.1 The continuous foundations and spread footings shall
extend a minimum depth of 18 inches into the firm natural ground or
compacted fill. The continuous foundations shall be reinforced with two
No. 4 steel bars; one bar shall be located near the top of the
foundations and one bar near the bottom.
2.3.2 Concrete floor slabs, if used, shall be founded on at least
four (4) inches of sand or decomposed granite, overlying visqueen. The
slabs shall be reinforced with 6 x 6 - 10/10 steel wire mesh.
I
Elm Garden Offices Job No. 82-2203
09 August 1982 Page 10
2.3.3 Prior to pouring footings and foundations, and prior to
placement of floor slab base sections, the clayey soils shall be thoroughly
watered such that they possess a moisture content of 2 percent above
optimum moisture content (or more) at a depth of 12 inches below the
footing grade.
2.3.4 It is recommended that all nonstructural concrete slabs
(such as patios, driveways, sidewalks, et cetera), and all parking areas, be
founded on at least four inches of nonexpansive soils.
Utilizing an Angle of Internal Friction of at least 25 degrees, and a cohesion of
300 pounds per square foot (with the appropriate Terzaghi Equation), the
maximum safe soil-bearing value (at a depth of 12 inches Into the natural
materials or compacted, fill soils on this site) is at least 2,= pounds per square
foot. This soil-bearing value may be utilized In the design of continuous
foundations and spread footings when founded a minimum of 12 inches Into the
firm natural ground or compacted fill. It is recommended that two-story
structures be founded on 18-inch deep footings and three-story. structures be
founded on 24-inch deep footings. This soil-bearing value may be increased
one third for design loads that include wind or seismic analysis.
4. Based on our laboratory test results and our experience with the soil types on
the subject site, the soils will experience settlement in the magnitude of less
than 0.5 inch under a structural load of 2,000 pounds per square foot.
S. The active earth pressure (to be utilized in the design of walls, et cetera), shall
be based on an Equivalent Fluid Weight of 50 pounds per cubic foot (for level
backfill only).
6. The passive earth pressure of the encountered natural-ground soils '(to be used
for design of building foundations and footings to resist the lateral forces)
shall be based on an Equhalent Fluid Weight of 350 pounds per cubic,foot.
Elm Garden Offices Job No. 82-2
09 August 1982 Page It
I 7. A Coefficient of Friction of 0.35 times the dead load may be used between the
bearing soils and concrete wall foundations o I r structure foundations and floor
I slabs. If the coefficient of friction is to be used in conjunction with passive
earth pressures, the coefficient shall be reduced to 0.3.
The compacted fill soils that occur within five feet of the face of the fill slopes
will possess poor lateral stability, even though they have been compacted.
I Proposed structures and other improvements (such as walls, fences, atios, side-
walks, swimming pools, driveways, asphalt paving et cetera), that are located
I within five feet of the face of compacted fill slopes, could suffer differential
movement as a resultof the poor lateral stability of these soils.
I
Foundations and footings of proposed structures, walls, et cetera, when found-
ed five feet and further away from the top of compacted fill slopes, may be of
standard design in dontormance with the recommended soil-bearing valUe. If
the proposed foundations and footings are located closer than five'feet Inside I the top of compacted fill slopes, they shall be deepened to one foot below a
line beghning at a point five feet horizontally Inside the fill slopes and
I projected, outward and downward, parallel to the face of the fill slope (see
Figure No. V).
I
' Following placement of concrete floor slabsH; sufficient drying time must be
I allowed prior to placement of floor coverings. Premature placement of floor
coverings may result, in degradation of adhesive materials and loosening of the
finish floor materials
It is recommended that all compacted fill slopes' and natural cut slopes be
I planted with an erosion-resistant plant, in conformance with the requirementS
of the City of Carlsbad.
Prior to placement of the fill soils, the toe of proposed fill slopes shall be
I stripped of all topsoils and keyed into firm ground, as determined by our
Engineering Geologist.
0 0 I
0
0 0
Qi OD
I
..H.. 0/3
Elm Garden Offices '•' Job No. 82,-2
09 August 1982 Page 12,
Inspection will be performed in the exposed cut areas by our Engineering
Geologist during the! future grading operation. If any unstable conditions or
irregularities are disclosed by these inspections, corrective action or additional
subsurface exploration may be required, if so recommended by our Engineering
Geologist. Further, grading plans for the northern portion of the site (when
finalized) should be presented to our firm for review to determine if further
recommendations are required.
Planter areas and planter boxes shall be sloped to drain away from the founda-
tions; footings and floor slabs. Planter boxes shall be constructed with a sub-
surface drain, installed in gravel, with the direction of subsurface and surface
flow away from the toundations, tootings and floor slabs, to an adequate drain-
age facility.
The existing debris and vegetation observed on the site must be removed prior
to the preparation of building pads and/or areas to receive structural Improve-
ments.
Existing surface soils, which will not be removed during the future grading opera-
tion, shall be scarified (in place) to a depth of 12 inches, watered to optimum
requirements, and shall then be compacted to at 'least '90 percent of Maximum
Dry Density.
Any backfill soils placed in utility trenches, or behind retaining walls, which
support structures and other improvements (such as patios, sidewalks, drive-
ways, pavements, et cetera), other than landscaping, shall be compacted to at
least 90 percent of Maximum Dry Density.
It is our opinion that compacted fill slopes of maximum inclinations Of 2.0
horizontal to 1.0 vertical shall be stable and free from deep-seated failures fOr
slopes not exceeding 25 feet In height. '
Elm Garden Offices Job No. 82-2J3
09 August 1982 Page
19. Adequate measures shall be taken to properly finish-grade the site after the
structures and other, improvements. are in place. Drainage waters from this site
and adjacent properties are to be directed away from foundations, floor slabs
and footings, onto the natural drainage direction for this area or Into roperly
designed and approved drainage facilities. Proper subsurface and surface drain-
age will help prevent waters from seeking the level of the bearing' soils under
the foundations, footings and floor slabs. Failure to observe this recommenda-
tion could result in uplift or undermining and differential settlement of the
structure or other improvements on the site.
Geotechnic2J Exploration, Inc. will assume no liability for damage to structures
which is attributable to poor drainage.
20. No subsurface structures shall be placed in the moderately to highly expansive
soils without being properly designed by a structural engineer and/or soils
engineer.
GRADING NOTES
Any required grading operations shall be performed in accordance with the general re-
quirements of the County of San Diego Grading Ordinance, under the supervision of a
qualified soils engineer or supervised field soils technician.
I It is the responsibility of the Owner and/or Developer to ensure that the recommenda-
tions summarized in this report are carried out in the field operations.
LIMITATIONS
Our conclusions and recommendations have been based on all available data obtained
I from our field investigation, and laboratory analysis, as well as our experience with the
soils and formational materials located in this .portion of the County of San Diego. Of
necessity, we must assume a certain degree of continuity between exploratory excava-
tions and/or natural exposures. It is, therefore, necessary, that all observations,
I ...
lrmmo •
I .. ....
,..
...
... ...
•
U
Elm Garden Offices Job No. 82-2203
09 August 1982 S Page 14
coñclusi,ns and recommendations be verified at the time grading operations begin, or
when footing excavations are placed. In the event discrepancies are noted, we should
be notified immediately so that an inspection can be made and additional recommenda-
tions Issuedi if required. Evaluation of geologic conditions in regard to landslides,
ground water1 et cetera, was carried out in accordance with the state-of-the-art and is
limited by available information in the literature and practical field investigations. The
field investigations were carried out in accordance with local accepted standards f9r
the period 19 which this report was written. The conclusions and recommendations
made in this report are based on the assumption that the geologic conditions do not
deviate appreciably from those geologic conditions disclosed in the subsurface
explorations and the evluation procedures are reasonably valid.
Compaction tests were taken in the existing fill soils to verify the relative densities.
The compaction tests were taken in randomly placed trenches and indicate the existing
fill soils were properly prepared and compacted. However, our firm cannot assume
liability for the Integrity of the entire fill pad since our firm was not present. during
the actual grading operation. The fill soils on the subject site were previously tested
(during the grading operation) by Southern California Testing Laboratory. The test
results are summarized in their report entitled, 'Report of In-Place Density Tests,
Tanglewood Subdivision, Carlsbad, California'.
S
This report should be considered valid for a period of three (3) years, and is subject. to
review by 0u1r firm following that time. If significant! modif I ications are made to the
building and/,or grading plans, especially with respect to the height and location of cut
and fill slopes and the height and location of proposed structures, this report must be
presented to us for immediate review and possible revision.
The firm of Geotechnlcal Exploration, Inc. shall not be held responsible for changes to
the physical condition of the property, such as addition of fill soils or changing
drainage patterns, which occur subsequent to isuance of this report.
ii
1EI;:11I:i!iii
I
/ Elm Garden Offices job No. 82-2203
09 August 1982 Page 15
I Once again, should any questions arise concerning this report, please do not hesitate
I to contact us. Reference to our Job No. 82-2203 will expedite response to your
Inquiries. •
Respectfully submitted,
CEOTECHNICAL EXPLORATION, INC.
I .
I Project C
I
I Cliffo . La Monte, R.C.E. 25241
JBR/CWL/pj
-4 Enclosures
I
I
I
I
••.• ;•
1
,
•
1'
44
I!;
T~1::, f 158'
FA
Vicinity Map
I
.--- 7/ _
-_
:\\
\
\ \\ .\ .::. .•:
ii \
\.•
.\\ •\\ •\\
I / / / \ \ '
\\\\\\
/\
\ \\\
\ \ .: •
A----------
I
5AL-1. jIt5Ql
\•.__-,---- -7
I
NOTE: This Plot Plan Is not to be used for legal
purposes. Locations and dimensions are approxi-
mate. Actual property dimensions and locations
of utilities may be obtained from the Approved
Building Plans or the As-Built" Grading Plans.
I
CAH/Nc2
LEGEND_ -.
--.._Existing Contours
Property Line
£ Street Centerline
Existing Slope
-4 Test Trench Location
Existing Fill Slope
.- Property Corners
Approximate location of
Z existing fill soil (Tested
,by Southern California
Testing Laboratory
Approximate location of
existing landslide area
and direction
This plot plan was prepared
from a topographic map drawn
by Brian Smith Engineers, 9-18-81
and on site reconnaissance.
(7
I H
I Log of Test Trenches
-2 O,
4 U. 0 _i f E todJ w9 a,c .
Soil Description E
-
0 (Unified Soil Classification)
• a 72 2 99 a
5- C.) o
test Trench No, 1
____
• Firm, damp, black, sa ndy clay
7—"
TOPSOIL (CL-CH)
LI Dense, damp, white-tan, silty fine sand ;
S.
FORMATION (SP-sM)
Dense, damp, green-tan, highly fractured claystone
with intermixed white sand (Sheared-Zone) (CL) , , FORMATION • S
- Dense, damp, highly fractured, pink/brown siltstone 1 2.
FORMATION (sM-CL)
15"'.
16
\ S5 5
17_
L8l
BOTTOM OF. EXCAVATION
O
0
Bag Sample :
Undisturbed Sample
5InPlace Density
55inPIace Moisture
Job No.
Figure No.
82-2203
2a
Log of Test Trenches
- — - o - % I
W w U.
D 0 j .- u Ø) C O
-
O
Soil Description •. E
(Unified Soil Classification) 0 a av
CL 9 a o C) o Wc.)
O Test Trench No. 2
2 Firm, damp, black sandy clay
I . TOPSOIL (CL-CH)
Dense, fractured, green-tan, sandy clay/c.laey sand
. . with intermixedfine to medium white sand
FORMATION (Shearzone')•
-
. S 1
105* 20
I J Dense, damp, highly fractured pink/brown siltstorie
1.
I iI FORMATION (sM-ML) 11.0
.12
-1-•.•
Dense, damp, white,finé to medium sand
I . 'FORMATION (s) '
121 9.5 +1.0
-- ..
1 lOt 8.9,
BOTTOM OF EXCAVATION
Bag Sample *InpIace Density I Job No 82-2203
Undisturbed Sample **In..Place Moisture Figure No..2b
iLs
Log of Test Trenches
Ew g .-
c u Soil Description g .
. (Unified Soil Classification) a E
CL I O cc E 06
- LLJ()
Trench No. 0 Test 3
1 Firm,very damp, mottled dark brown to ta n, sandy
clay( clayey sand
2 REWORKED TOPSOIL I (Sc-CL)
Medium dense, damp, green-tan, clayey fine sand 1.
L RESIDUAL FORMATION (Sc)
5.. Medium dense to dense, damp, white, fine to medium
sand
7
ic
11 •
SS
S
FORMATION (SP)
S
BOTTOM OF EXCAVATION
O Bag Sample *InPIace Density Job No. 82-2203
o Undisturbed Sample **InPIace Moisture Figure NO. 2 c
00 r' r r t o Depth in Feet
Graphic Log
II
—
CD
-' O..(D 0-0
—
-•CD CD .-
* — CD — =
0 - rt 0 ' -I -1 - 0r0 0 --
CO C)B 3,-o
flo) (D9fl =
o
m • - .)CrP CCDCD
- rn a 30-0. to
C — ><
C-,
- 0 -4
- 0 00
-
• -Ln --
-cici. --
U)
C-) •<0
S
- Maximum
- Dry.-Density: Zr
• — Moisture PCO F - (% Dry Weight) -
Relative
-
C) Compaction %
Expansion (+)or
Consolidation (-)
Log of Test Trenches
— w - 0) — -
o
Soil Description
0)
a .22
t
.
. CL (Unified Soil Classification) a
CL 2
o o wo
O Test Trench No. 5
H 1 Fi:rm, damp, black, sandy clay 11:5 13. +6.5
I
3 TOPSOIL (CL-CH)
4.
1
112 10.5 +3.3 -
. Medium dense, highly fractured, very damp, tan—brown, 7
- 'tO silty clayey fine sand
FORMATION (SM-SC) -
11 Dense, damp, tan-white, fine to medium sand
12
13
FORMATION (SP)
BOTTOM OF EXCAVATION -
O Bag Sample *lnplace Density Job NO.
o Undisturbed Sample **lnPlaCe Moisture Figure No.2,0
Q-)
01 0: - ' -- r r' i - tj TO V. n-° iCO Depth In Feet
Graphic Log CL U2
•
-. •
-hx - —.(
• -n 3 ty -0 -
-
-- CD
CL - CD—•
-. (F)
3
(1)3 r (D a) B C) m (1) - CD - 0 rt o a) -' — C 0 0
- —I 0 -i - 0 - U) 0 -' -V 0 -
- -
- CD (/) a 0
0
m
.-
—1
— - Or,
- Q M ><
— a) 0 3 - (1) a) - ca n
orn
-.
C)- - Q_ - (0 (0-
m - — 0 -<
- r a)
U)
C-)
-
C) - -C):
- - Maximum-
- - - a> - Dry, Density,
— - - Moisture CO
- - (%- Dry Weight)
Relative -
- Compaction- % -
'S-') Expansion (+)or - •
- Consolidation (-)
Log of Test Trenches
I--.
0I
W U.
.a 0
_I
,>. C—
in
.
D .-
a
C d)0 +
C., Soil Description g
(Unified Soil Classification) M , a
CL
0
o . Test Trench No. 7
Well compacted, very damp, brown to white,
- '
fine to medium sand, some, intermixed
2 black/light brown, sandy clay
3 ,'m FILL (Si')
Q9c 5'c 91.
-
Well compacted, very damp, intermixed, dark brown
sandy clay and tan fine to medium sand
FILL . (SP-SC-CL)
11* 11.7 92
13 Firm,' damp, black, sandy clay
1 4 N TOPSOIL (CL-CH)
15 Dense, highly fractured, damp,.green-tan, siltston'E
if I FORMATION (ML) .
BOTTOM OF EXCAVATION
Bag Sample . *In -Place Density Job NO. 82-2203
OIlndisturbed Sample 44InPIace Moisture . . Figure NO.2 .g
00 Depth in Feet
'1Z
Graphic Log
nn-•:
0' rP
- <<CDCD VV .R V.
— CD-P m V
.CDQ.0
— C -•CD 03 0. —
11 rC CL 0 -1 - 0r0 V CD3 CA-
- 00 V -
C —•>Ce-P V (D(D - fc)
m '
CA M
QO. r) QJQj
- 0
- — 0Dr
C) - V VV.V 00 -
V CD - - V
VVV
- V. .- •V ' -< Ln
V V. V
- V
V
V Ct
V
Maximum
C' Cr V
V Dry Density,
(D oi V V V Moisture Or
V • (% Dry Weight)
V
V Relative V V
-
V Compaction %
Expansion (+)or V
V V.
Consolidation (-)
® 0 'r° r r-' ' r v r- Depth in Feet
.
V
-
. ;// 11 7 Graphic Log CL V.
,1 / /,' /. / V •/ T / '. / - ___________
Cr • CD
CL —0 r1
(I)
___________ — — -V-V-V • — ____
V
_VV____V V —. CD___s __V.1VV-V V_
-< C0. CD.
m .
rtCDr1- -CDQ.0 z
C
0-
ca
ID
2 • -
-
CL
- H . CD3
- . 00
m m X QL rj
.
— m
-V
om Ba--
)1 >( Qo_._
m • - _o•
0)
0
H . 00r1 _
-' -;0 00
V V V-V _VVV_V V
-'
!J V V V
V . - __V . V -V_ V .-- • - -0 w ._ I rt.Qj c-fl V
V C)
. . ri 4r . Maximum
Dry Density * V
0. — - Moisture Z . •
(% Dry Weight)'
V
. . .. Compaction %
Expansion (+)Or
Consolidation (-)
I H
I Log of Test Trenches--.--.-----
— I — - 0 0 I —
LL _j
H
Soil Description t co
. (Unified' Soil Classification) a
CL 1' 'oE
Test Trench No. 10
Firm, damp, black, sandy clay
I TOPSOIL (CL-cu) I,
Dense, fractured,' damp, green, ray,Lhsiitstone
FORMATION-
1!
OF
L
BOTTOM EXCAVATION,
ii
o Bag Sample in-Place Density
Job No. 82-2203
Undisturbed Sample E)0 **In..place Moisture Figure NÔ.2J.
I 130
APPARENT COHESION psf)
FILL SUOTABLOTY TESTS
DIRECT SHEAR TEST DATA I 2 3
300
,APPARENT FRICTION ANGLE j 25°
III
Ism
kBBLE
SjGRAVELI SAND
C F id M F SILT CLA
I 90
2.70
-2.60 SPECIFIC GRAVITY
2.50
'ZERO AIR VOIDS CURVES
40 10 20 30
LABORATORY COMPACTION TEST
SOIL SOIL CLASSIFICATION BORING TRENCH DEPTH
TYPE NO. NO.
I Pink!- brown, siiitstone 9'
2 White, fine to medium sand •2 15'
B1ack sandy-clay 5 1 2'
SWELL TEST DATA I 2 1 3
INITIAL DRY DENSITY (pcf) 113 117 1 113
INITIAL WATER CONTENT (%.) 9% 8% 1 10%
LOAD (psi) ii+z 14 iz+
PERCENT SWELL +)3.3 +)i.0 +)6.5
JOB NO: 82-2203
FIGURE NO III
-I ,
APPENDIX A
UNIFIED SOIL CLASSIFICATION CHART
I
SOIL DESCRIPTION :
I COARSE-GRAINED
More than half of material Is larger than a No; 200 sieve
CLEAN GRAVELS
I
GRAVELS,
More than half of coarse fraction is larger than -- GW Well-graded gravels, gravel and sand mix-
No. 4 sieve size, but smaller than 3" tures, little or no fines.
I GP Poorly graded gravels, gravel and sand mix-
tures, little or no fines.
GRAVELS WITH FINES . GM Silty gravels, poorly graded gravel-sand-silt
(appreciable amount) . mixtures.
GC Clay gravels, poorly graded gravel-sand-silt
mixtures.
I
.
SANDS, CLEAN SANDS SW Well-graded sand, gravelly sands, little or no
More than half of coarse fraction is smaller than a no fines.
No. 4 sieve. I SP Poorly graded sands, gravelly sands, little or
no fines.
SANDS WITH FINES ' SM Silty sands, poorly graded sand and silty I (appreciable amount) mixtures..
SC Cläyey sands, poorly graded sand and clay
I mixtures.
.
FINE-GRAINED
Mdre than half of material Is smaller than a No. 200 sieve I .
SILTS AND CLAYS . . ML Inorganic silts and-very fine sands, rock flour,
. sandy silt and clayey-silt 'sand mixtures with I ...
a slight plasticity.
Liquid Limit Less Than 50 . CL Inorganic clays of low to medium plasticity,
I gravelly clays, sandy clays, silty days, clean
clays. .
OL Organic silts and organic, silty clays of low
I plasticity. . • .
. MH Inorganic silts, micaceous or diatomaceous
fine sandy or silty soils, elastic silts.
I' Liquid Limit Greater Than 50 CH Inorganic clays of high plasticity, fat clays.
.. OH Organic clays of medium to high plasticity.
I HIGHLY, ORGANIC SOILS . PT Peat and other highly organic soils.
1 APPENDIX B
GRADING SPECIFICATIONS
I
General
U The intent of this item is to properly establish procedures for: cleaning and compacting natural ground, pre-
paring areas to be filled, and placing and compacting fill material to the grades and slopes as shown on the
Grading Plans. .
Clearing
All vegetation, brush and debris shall be removed, piled and burned, or otherwise disposed of, to give the sur-
face a neat and finished appearance.
I Compacting Natural Ground
After clearing, the natural ground shall be scarified to a depth of at least 12 inches, watered to optinum
requirements and compacted to not lest, than 90 percent of maximum dry density, according to A.S.T.M. Test
Method 0-1557, in a four-inch diameter, cylindrical mold of 1/30th-cubic-foot volume. Field density tests shall
be taken in the natural ground in accordance with A.S.T.M. Test Method D-1556.
Fill Materials
Materials for the fill shall be approved by the soils engineer and shall be free from organic matter and other
deleterious substances. In the event that expansive materials are encountered within three feet of finished
grade, they shall either be entirely removed or thoroughly mixed with good, granular material before incorpo-
rating them in fills. No footing shall be allowed to bear on soils which, in the opinion of the soils engineer, are
detrimentally expansive—unless designed for this clayey condition. .
Placing and Compacting Fill Material
After preparing the areas to be filled, the fill materials shall be placed in layers not to exceed six inches in
compacted thickness. Each layer shall be watered to optimum requirements and compacted to not less than 90
percent of maximum dry density in accordance with A.S.T.M. Test Method 0-1557. Compaction of the fill shall
then proceed in the specified manner to the grades as shown on the approved plans.
When the slope ratio of the original ground is steeper than five-horizontal-to-one-vertical, the original
ground shall be benched. Ground slopes flatter than five-horizontal-to-one-vertical shall be benched when
considered necessary by the soils engineer. Fill slopes shall be compacted by means of a sheepsfoot roller, or
other suitable equipment. Slope compaction shall be continued until the slopes are stable but not too dense for
planting. ,
Field deAsity tests shall be taken when considered necessary by the soils engineer in accordance with
A.S.T.M. Test Method 0-1556 and shall be made not exceeding two feet in vertical height providing each layer is
tested.
Supervision
Continuous supervision of the fill shall be made by the representative of Geotechnical Exploration, Inc.,
during the grading operation so that he can certify that the fill was placed in accordance with these
I, specifictions.
Season Limits
I,
No fill material shall be placed, spread or rolled during unfavorable weather conditions. When the work is
int • errupted by heavy rains, the filling operation shall not be resumed until field tests indicate that the moisture
content and density of the fill are as previously specified.
I
I.
,,
. 33
I
I - -
I
CROSS SECTION A-A'
Job No 82-2203 EAST
tFigure No IV
13
Trench to
Existing round Surface
20'
1166 -. - -
T 2 . Trench c ' o rooed -
Ca Pr000se ','a 11
o5ose
140 Drain i ons
ui
20 46 60 80 100 120 iLiO 160 180 200 220 2L0 260 28-0 300'
A A'
I I I I
30
A.
Prosed Structure
Concrete Floor Slab
51 OH Top of Compacted Fill Slope
0 - 0
Compacted Fill Slope
- _--- I - (Maximum Inclination 1.5:1.0)
-
}einforcement of
a - Foundations and Floor
Slabs following the Rec.- .. Total De h of Footing
omeridations of the Architect -
or Structural gineer. .--- .-----
_.-__\ .---
Compacted Fill
Conrete Foundation p 12". Minimum
-. _.-
p
-,,_= 1--.•
- - - 51 0
TYPICAL SCTI0N
(Showing Proposed Foundation located Within Five Feet of Top of Compacted Fill S].ope)
TOTAL DEPTH OF FOOTING
DISTANCE FROM
TOP OF SLOPE
1.5 :1.0 Fill Slope 2.0 : 1.0 Fill Slope
C) 52" 42"
1 44" 36"
2 36" 30"
I 28" 24"
IL 20" 181,
Job No. 82-2203 ,
Figure No. v