1990-541 G/H Street Address
Category Serial #
Name Description
Plan ck. # Year
recdescv
CALIFORNIA
_ ENGINEERING
CORP & L
CEC #90 -071
8/29/90
REV, 1 1/26/90 �Z
DRAINAGE STUDY FOR PARCEL 2 OF P.M. 12127.
THE SITE RISES ABOVE TRABLER RANCH DRIVE + 20' WITH A COMBINATION
OF EXISTING RETAINING WALL AND CUT SLOPE. THERE IS AN EXISTING
EARTHEN SWALE AT THE TOP OF THE CUT BANK THAT FLOWS TO THE
SOUTHWEST CORNER OF THE SITE. THERE IS ALSO AN EXISTING NATURAL
SWALE THAT FLOWS FROM THE CENTER OF THE SITE TO THE SOUTHEAST
CORNER OF THE SITE.
THE DEVELOPMENT OF THIS SITE PROPOSES THE INSTALLATION OF A
PRIVATE S.D. SYSTEM THAT WILL PICK -UP THE DRAINAGE IN THE
EXISTING EARTHEN SWALE FROM THE NORTH. THIS SYSTEM WILL ROUTE
ALL RUNOFF FROM THE NORTH AND PROPOSED PAD RUNOFF TO THE EXISTING
EARTHEN SWALE SOUTH OF THE AREA TO BE IMPROVED. NO CHANGES OR
ADDITIONAL RUNOFF ARE PROPOSED FOR THE EXISTING NATURAL SWALE.
MN 2 81990
VICTOR RODRIGUEZ - FERNANDEZ R.C.E. 35373 EXP. 9 -30 -91 DATE
4440 RAINIER AVENUE SUITE 210, SAN DIEGO, CALIF. 92120
TELEPHONE (619) 281 -3122
b r— 13
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APPEWIX XI IV -A -14
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URBAN 0�, ID
AREAS R
TIME OF FLOW CURVES
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plriSIOW Two )YksK, D -C_' WATER POND ED ON GRATE .
' ASSUME 25 g6 Cj _OGGWG -
• -59-
(Z or . ,
-� TABLE 2
RUNOFF COEFFICIENTS (RATIONAL METHOD)
DEVELOPED AREAS (URBAN)
Coeffi C
Soil Group (1)
Land Use
A 8 C D
Residential:
Single Family .4a .45 .50 .55
Multi -Units .45 .50 .60 .70
Mobile homes . 45 .50 .55 .65
Rural (lots greatPF than 1/2 acre) .30 .35 .40 .45
Commercia]( .70 .75 .80 .85
809 Impervious
I n d u s t r i a l ( 2 ) . .85 .90 .95
90% Impervious
NOTES;
( ' ) Soil Group =a-.)s are available at the offices of the Department of Public Works.
( actual conditions deviate significantly from the .tabulated impervious-
ness values of 80% or . 'the values given for coefficient C, may be revised
by multiplying 80;; or 90% by the ratio of actual imperviousness to the
tabulated imperviousness. However, in no case shall the final coefficient
be less than 0.50. For example; Consider commercial property on D soil :group.
Actual imperviousness 50
Tabulated imperviousness = 801%
Revised C =2 x 0.85 = 0.53
SO
k
IV -A -9
APPENDIX IX -B
Rev. 5/81
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REPORT OF v (�
GEOTECHNICAL INVESTIGATION
PROPOSED CHAMBERS RESIDENCE
1375 TRABERT RANCH ROAD
' ENCINITAS, CALIFORNIA
PREPARED FOR:
' Mr. Jim Chambers
315 South Highway 101
Solana Beach, California 92075
PREPARED BY:
Southern California Soil and Testing, Incorporated
' 6280 Riverdale Street
San Diego, California 92120
Post Office Box 600627, Zip Code 92160
< ; rjil�
SOUTHERN CALIFORNIA SOIL AND TESTING, INC.
February 11, 1991
Mr. Jim Chambers
' 315 South Highway 101 SCS &T . 1
3
Solana Beach, California 92075 Report N Noo.
' SUBJECT: Report of Geotechnical Investigation, Proposed Chambers Residence,
1375 Trabert Ranch Road, Encinitas, California.
' Dear Mr. Chambers:
In accordance with your request, we have completed a geotechnical investigation for the
' proposed project. The findings and recommendations or our study are presented herewith.
In general, we found the site suitable for the proposed development provided the
' recommendations presented in the attached report are followed.
If you have any questions after reviewing the findings and recommendations contained in
' the attached report, please do not hesitate to contact this office. This opportunity to be of
professional service is sincerely appreciated.
' Respectfully submitted,
SOUTHEr CALIFORNIA SOIL AND TESTING, INC.
/U
Da iel B. Adler, R. E. #36037 Curtis R. Burdett, C.E.G. #1090
DBA:CRB:mw @RpUSS1 ��ED GEO�
' cc: (6) Submitted ��0 \Ev B. A p
(1) SCS &T, Escondido y Q �
N0. 36037 U CERTIFIED
' ENGINEERING
#
EXP. 6-30-92 * GEOLOGIST
6 -30.92
�r'4jf OF CAItiE a\ 9TF O
F C
' 6280 RIVERDALE STREET • SAN DIEGO, CA 92120 619 -280 -4321, FAX 619 -280 -4717 • P.O. BOX 600627, SAN DIEGO, CA 92160
678 ENTERPRISE STREET • ESCONDIDO, CA 92029 • 619 - 746 - 4544, FAX 619 - 746 -6579
TABLE OF CONTENTS
' PAGE
Introduction and Project Description ............................................ ............................... 1
ProjectScope ......................................................................... ............................... 1
Findings............................................................................... ............................... 2
SiteDescription ............................................................ ............................... 2
General Geology and Subsurface Conditions ......................... ............................... 3
' Geologic Setting and Soil Description ......................... ............................... 3
Delmar Formation ( Td) ................................... ............................... 3
Torrey Sandstone ( Tt) ..................................... ............................... 3
Slopewash adn Alluvium ( Qsw/ Qal) ..................... ..............................3
' Topsoil ....................................................... .......:......... 4
Artificial Fill (Qaf).... .............. ......... 4
GeologicHazards .......................................................... ............................... 5
' Groundshaking .................................................... ............................... 5
Landslides........................................................... ............................... 5
Conclusions and Recommendations .............................................. ............................... 6
General...................................................................... ............................... 6
' Grading ...................................................................... ............................... 6
SurfaceDrainage ................................................... ............................... 6
Earthwork........................................................... ............................... 6
SlopeStability .............................................................. ............................... 7
' Unshored Slopes ................................................... ............................... 7
PermanentSlopes .................................................. ............................... 7
Foundations................................................................. ............................... 7
General.............................................................. ............................... 7
' Reinforcement ...................................................... ............................... 8
Interior Concrete On -Grade Slabs .............................. ............................... 8
' Exterior Slabs -on- Grade .... 8
....................... ...............................
Expansive Characteristics.. ............... 8
Settlement Characteristics ........................................ ............................... 9
Grading and Foundation Plan Review ................................. ............................... 9
EarthRetaining Walls .................................................... ............................... 9
' Passive Pressure ................................................... ............................... 9
ActivePressure ..................................................... ............................... 9
' Backfill .............................................................. ............................... 9
TABLE OF CONTENTS (continued)
PAGE
Factorof Safety ............................... ...............................
' Limitations ............. ............................... 0
Review, Observation and Testing ..................................... ............................... 10
' Unformity of Conditions ......... ............................... ......... 10
Changein Scope ......................................................... ............................... 11
' Time Limitations ......................................................... ............................... 11
ProfessionalStandard ................................................... ............................... 11
Client's Responsibility .................................................. ...............................
12
FieldExplorations. ..................................................... ............................... 12
Laboratory Testing ............ ...............................
ATTACHMENTS
FIGURE
Figure 1 Site Vicinity Map, Follows Page 1
' PLATES
Plate 1 Plot Plan
' Plate 2 Cut Slope Log
Plate 3 Subsurface Exploration Legend
' Plate 4 Pit Logs
Plate 5 Grain Size Distribution
Plate 6 Direct Shear Test
Plate 7 Slope Stability Calculations
Plate 8 Detail Weakened Plane Joint Detail
' Plate 9 Retaining Wall Subdrain Detail
' APPENDIX
Recommended Grading Specifications and Special Provisions
■
■
z ruo
■
SOUTHERN CALIFORNIA SOIL AND TESTING, INC.
■
GEOTECB NICAL INVESTIGATION
■
CHAMBERS RESIDENCE
■ 1375 TRABERT RANCH ROAD
ENCINITAS. CALIFORNIA
■
INTRODUCTION AND PROJECT DESCRIPTION
■
This report presents the results of our geotechnical investigation for the proposed Chambers
Residence to be located at the northern terminus of Trabert Ranch Road, in the City of Encinitas,
California. The site is legally described as Parcel 2, P.M. 12127. The site location is illustrated on
the following Figure Number 1.
■
It is our understanding that the site will be developed to receive a one and two -story split - level,
■ residential structure and a swimming pool. The structure will be of masonry and wood -frame
construction. Shallow foundations as well as conventional slab -on -grade floor systems are
' anticipated. Masonry retaining walls up to 15 feet high are proposed. Grading will consist of cuts up
to 20 feet below existing grade and minor fills.
■
To assist in the preparation of this report were were provided with an undated grading plan prepared
by California Engineering Corporation. The site configuration, topography and approximate
locations of our subsurface explorations are shown on Plate Number 1 of this report.
1
PROJECT SCOPE
The investigation consisted of: surface reconnaissance, subsurface explorations, obtaining
representative disturbed and undisturbed samples, laboratory testing, analysis of the field and
■
6280 RIVERDALE STREET ♦ SAN DIEGO, CA 92120.619 -280 -4321, FAX 619 -280 -4717 ♦ P.O. BOX 600627, SAN DIEGO, CA 92160
678 ENTERPRISE STREET • ESCONDIDO, CA 92029 • 619 - 746 -4544, FAX 619-746 -6579
' SCS &T 9121003 February 11, 1991 Page 2
' laboratory data, research of available geological literature pertaining to the site, and preparation of
this report. More specifically, the intent of this analysis was to:
a
Explore the subsurface conditions to the depths influenced by the proposed
' construction.
b) Evaluate, by laboratory tests, the pertinent engineering properties of the various
strata which will influence the development, including their bearing capacities,
expansive characteristics and settlement potential.
c) Describe the general geology at the site including possible geologic hazards which
' could have an effect on the site development.
d) Develop soil engineering criteria for site grading and provide recommendations
regarding the stability of temporary and permanent slopes.
e) Address potential construction difficulties and provide recommendations concerning
' these problems.
f) Recommend an appropriate foundation system for the type of structures anticipated
and develop soil engineering design criteria for the recommended foundation design.
FINDINGS
SITE DESCRIPTION
' The subject site is a irregularly shaped parcel of land, approximately 1.2 acres in size, located at
1375 Trabert Ranch Road in the City of Encinitas, California. The site is bounded by open, vacant
land to the north and east, Trabert Ranch Road to the west, and residential property to the south.
Topographically the site consists of a north -to- south - trending ridge bounded on the west and east
by relatively steep slopes. The eastern slope dips to the east and comprises approximately
two -thirds of the site, this slope has an approximate inclination of 2:1 (horizontal to vertical) over
' a distance of approximately 180 feet. The western slope dips to the west, from the ridge to the
SCS &T 9121003 February 11, 1991 Page 3
' adjacent access road, with an inclination of approximately 1.5 to 1 (horizontal to vertical). In
addition, the ridge itself dips to the south with an inclination of approximately 4 to 1 (horizontal to
vertical). On -site elevations range from approximately 90 feet to 200 feet (MSL). A small,
erosional scarp is located on the east- facing slope between elevations of 175 feet and 190 feet
(MSL).
At the time of our investigation, the site was improved by an asphaltic concrete paved access road
along the western border and an adjacent concrete masonry block wall approximately three feet in
height. The site is covered by native grasses and shrubs.
GENERAL GEOLOGY AND SUBSURFACE CONDITIONS
GEOLOGIC SETTING AND SOIL DESCRIPTION: The subject site is located in the lower
California Physiographic Province of the United States and within the Coastal Plains Province of
San Diego County. The site is underlain by deposits of sedimentary origin. In decreasing order of
' age, the native materials at the site consist of the Delmar Formation (Td), the Torrey Sandstone
(Tt), and slopewash and alluvium (Qsw /Qal). A brief description of each of these geologic
materials is presented below.
DELMAR FORMATION (Td): The oldest materials exposed at the site are the
sandstones, siltstones, and claystones of the Eocene -age Delmar Formation. In the vicinity
of the project site, the Delmar Formation consists largely of nearly horizontally bedded,
' greenish- brown, sandy siltstones and claystones with interbeds of medium to coarse
grained sandstone.
' TORREY SANDSTONE (Tt): Overlying the Delmar Formation are the buff to yellowish
' brown, dense to very dense sandstones and siltstones of the Eocene Torrey Sandstone. The
Torrey Sandstone is present above an approximate elevation of 140 to 145 feet at the
project site, and is exposed in the cut slope east of the access road.
SLOPEWASH AND ALLUVIUM (Qsw /Qal): The Quaternary -age slopewash and
alluvial deposits consist of poorly consolidated surficial materials that have been derived
from the nearby bedrock sources and redeposited along the sloping portions of the site.
SCS &T 9121003 February 11, 1991 Page 4
' These deposits generally consist of brown, loose to medium dense, fine silty sands, and
range in thickness from less than one foot to a few feet.
TOPSOIL: Topsoil was as observed in Pit Number 1, with a thickness of approximately one
' foot. The topsoil consists of brown, medium dense, fine silty sand.
' ARTIFICIAL FILL (Qat): Artificially placed fill soils are present as a thin surficial layer
over the northernmost portion of the ridge top, and may be present along the western edge
of the access road. Thicknesses on the ridge top are estimated to range from less than one
foot to as much as four feet. If fill soils are present along the western edge of the access
road, maximum thickness are likely to be less than ten feet. The observed fill soils consist
of brown, medium dense, fine silty sand.
TECTONIC SETTING: No faults are known to traverse the subject site but it should be noted,
however, that much of Southern California, including the San Diego County area, is characterized
by a series of Quaternary -age fault zones which typically consist of several individual, en echelon
faults that generally strike in a northerly to northwesterly direction. Some of these fault zones (and
the individual faults within the zone) are classified as active while others are classified as only
potentially active according to the criteria of the California Division of Mines and Geology. Active
fault zones are those which have shown conclusive evidence of faulting during the Holocene Epoch
(the most recent 11,000 hears) while potentially active fault zones have demonstrated movement
during the Pleistocene Epoch (11,000 to 2 million years before the present) but no movement
during Holocene time.
A review of available geologic maps indicates that the active Rose Canyon Fault Zone is located
approximately six miles west of the site. The recent seismic events along a small portion of the
' Rose Canyon Fault Zone generated earthquakes of magnitude 4.7 or less. Other active fault zones
in the region that could possibly affect the site include the Coronado Banks and San Clemente
Fault Zones to the southwest and the Elsinore and San Jacinto Fault Zones to the northeast.
SCS &T 9121003 February 11, 1991 Page 5
GEOLOGIC HAZARDS
GROUNDSHAKING: The most likely geologic hazard to affect the site is groundshaking as a
result of movement along one of the fault zones mentioned above. The maximum bedrock
' accelerations that would be attributed to a maximum probable earthquake occurring along the
nearest portion of selected fault zones that could affect the site are summarized in the following
Table I.
TABLE I
' Maximum Probable Bedrock Design
Fault Zone Distance Earth uake Acceleration Acceleration
Rose Canyon 6 miles 6.5 magnitude 0.42 g 0.32 g
Coronado Banks 16 miles 7.0 magnitude 0.25 g 0.17 g
Elsinore 27 miles 7.3 magnitude 0.08 g 0.05 g
San Jacinto 50 miles 7.8 magnitude 0.12 g 0.08 g
San Clemente 50 miles 7.3 magnitude 0.08 g 0.05 g
Earthquakes on the Rose Canyon Fault Zone are expected to be relatively minor. Major seismic
' Y J c
events are likely to be the result of movement along the Coronado Banks, San Jacinto, San Clemente
r or Elsinore Fault Zones.
Experience has shown that structures that are constructed in accordance with the Uniform Building
Code are fairly resistant to seismic related hazards. It is, therefore, our opinion that structural
damage is unlikely if such buildings are designed and constructed in accordance with the minimum
standards of the most recent edition of the Uniform Building Code.
LANDSLIDES: The site is located in a area where landslides are relatively common. A number of
' landslide features have been observed in the vicinity of the site, although they are generally minor in
extent. The Torrey Sandstone is fairly resistant to landsliding,while the siltstones and claystones of
the Delmar Formation can be susceptible to landsliding under certain conditions. Based on a review
of the geologic conditions and topographic configuration of the site, it is our opinion that any
landsliding which might occur in the future would be surficial in nature, and would be limited in
vertical and lateral extent. Such landsliding would not possess a major threat to the stability of the
site. It is our further opinion that the proposed natural, cut, and fill slopes will possess an adequate
factor -of- safety with respect to gross stability.
t SCS &T 9121003 February 11, 1991 Page 6
CONCLUSIONS AND RECOMMENDATIONS
GENERAL
' In general, no geotechnical conditions were encountered which would reclu
p de the construction of
the proposed development as presently proposed provided the recommendations presented herein are
followed.
' The main geotechnical condition is the temporary cut slopes required for the construction of the
proposed retaining wall. It is anticipated that the slopes will be unshored. The stability of different
slope configuration has been analyzed and appropriate recommendations are provided hereinafter.
GRADING
Grading for the site will consist primarily of cuts up to 15 feet in depth. This operation will result in
the removal of any existing vegetation and most of the loose surface soil. Any remaining slopewash
' and /or fill in areas to receive settlement sensitive improvements should be removed to firm natural
ground. The soil exposed at the bottom of the excavation should be scarified to a depth of 12 inches,
moisture - conditioned and recompacted to at least 90 percent. The soils removed should then be
placed in six -to- eight- inch -thick compacted layers until desired elevations are reached.
SURFACE DRAINAGE: It is recommended that all surface drainage be directed away from the
proposed structure and the top of slopes. Ponding of water should not be allowed adjacent to the
foundations.
EARTHWORK: All earthwork and grading contemplated for site preparation should be
accomplished in accordance with the attached Recommended Grading Specifications and Special
Provisions. All special site preparation recommendations presented in the sections above will
supersede those in the Standard Recommended Grading Specifications. All embankments, structural
till and fill should be compacted to at least 90% relative compaction at or slightly over optimum
moisture content. Utility trench backfill within five feet of the proposed structures and beneath
asphalt pavements should be compacted to minimum of 90% of its maximum dry density. The upper
SCS &T 9121003 February 11, 1991 Page 7
' twelve inches of subgrade beneath paved areas should be compacted to 95 of its maximum dry
density. This compaction should be obtained by the paving contractor just prior to placing the
aggregate base material and should not be part of the mass grading requirements. The maximum dry
density of each soil type should be determined in accordance with ASTM Test Method D 1557 -78,
Method A or C.
SLOPE STABILITY
UNSHORED SLOPES: It is our opinion that unshored excavations may be constructed vertically to
' a maximum height of five feet. Unshored excavations to a height of ten feet may be constructed at a
continuous 0.5:1 (horizontal to vertical) inclination. Unshored excavations up to 15 feet in height
may be constructed at a continuous 0.75:1 inclination (see Plate Number 7). No surcharge loads
should be placed within a distance from the top of the excavation equal to half of its height. These
recommendations assume temporary cuts exposing dense formational deposits. Temporary cuts
should be observed by a representative from this office in order to verify that the soil conditions
exposed by the cut are as anticipated.
PERMANENT SLOPES: Cut slopes extending to a maximum height of about 20 feet at a 2:1
(horizontal to vertical) inclination are proposed. It is our opinion that these slopes will possess an
adequate factor -of- safety with respect to deep seated rotational failure (see Plate Number 7). Cut
slopes should be observed by a representative from this office in order to verify that the soil
conditions exposed by the cut are as anticipated.
FOUNDATIONS
GENERAL: Shallow foundations
may be utilized for the support of the proposed structures. The
footings should have a minimum depth of 12 inches and 18 inches below lowest adjacent finish pad
grade for the one - and - two -story portions of the structure, respectively. A bearing capacity of 2500
psf may be assumed for said footings. This bearing capacity may be increased by one -third when
considering wind and /or seismic forces. Footings located adjacent to or within slopes should be
extended to a depth such that a minimum distance of six feet and seven feet exist between the bottom
of the footing and the face of cut slopes or natural slopes, respectively. For retaining walls this
minimum distance should be increased to ten feet.
SCS &T 9121003 February 11, 1991 Page 8
REINFORCEMENT: Both exterior and interior continuous footings should be reinforced with one
No. 5 bar positioned near the bottom of the footing and one No. 5 bar positioned near the top of the
footing. This reinforcement is based on soil characteristics and is not intended to be in lieu of
reinforcement necessary to satisfy structural considerations.
INTERIOR CONCRETE ON -GRADE SLABS: Concrete on -grade slabs should have a thickness
of four inches and be reinforced with at least No. 3 reinforcing bars placed at 36 inches on center
each way. Slab reinforcement should be placed near the middle of the slab. As an alternative, the
slab reinforcing may consist of 6 "x6 " -W 1.4xW 1.4 (6 "x6 "- 10 /10) welded wire mesh. However, it
should be realized that it is difficult to maintain the proper position of wire mesh during placement
p of the concrete. A four - inch -thick layer of clean, coarse sand should be placed under the slab. This
layer should consist of material having 100 percent passing the one - half -inch screen; no more than
25 percent, ten percent and five percent passing sieve #16, #100 and #200, respectively. Where
moisture- sensitive floor coverings are planned, the sand or rock should be overlain by a visqueen
moisture barrier and a two - inch -thick layer of sand or silty sand should be provided above the
visqueen to allow proper concrete curing.
EXTERIOR SLABS -ON- GRADE: For nonexpansive soil conditions, exterior slabs should have
a
minimum thickness of four inches. Walks or slabs five feet in width should be reinforced with
6 "x6 "- W1.4xW1.4 (6 "x6 "- 10/10) welded wire mesh and provided with weakened plane joints. Any
slabs between five and ten feet should be provided with longitudinal weakened plane joints at the
center lines. Slabs exceeding ten feet in width should be provided with a weakened plane joint
located three feet inside the exterior perimeter as indicated on attached Plate Number 8. Both
traverse and longitudinal weakened plane joints should be constructed as detailed in Plate Number 8.
Exterior slabs adjacent to doors and garage openings should be connected to the footings by dowels
consisting of No. 3 reinforcing bars placed at 24 -inch intervals extending 18 inches into the footing
and the slab.
EXPANSIVE CHARACTERISTICS: The prevailing foundation soils were found to be
nondetrimentally expansive. This condition is reflected on the recommendations of this report.
SCS &T 9121003 February 11, 1991 Page 9
SETTLEMENT CHARACTERISTICS: The anticipated total and /or differential settlements for
the proposed structure may be considered to be within tolerable limits provided the
recommendations presented in this report are followed. It should be recognized that minor cracks
normally occur in concrete slabs and foundations due to shrinkage during curing or redistribution of
stresses and some cracks may be anticipated. Such cracks are not necessarily an indication of
excessive vertical movements.
GRADING AND FOUNDATION PLAN REVIEW
The grading and foundation plans should be submitted to this office for review in order to ascertain
that the recommendations presented in this report have been implemented.
EARTH RETAINING WALLS
PASSIVE PRESSURE: The passive pressure for the prevailing soil conditions may be considered
to be 350 pounds per square foot per foot of depth up to a maximum of 1500 psf. This pressure may
be increased one -third for seismic loading. The coefficient of friction for concrete to soil may be
assumed to be 0.30 for the resistance to lateral movement. When combining frictional and passive
resistance, the former should be reduced by one -third. The upper 12 inches of exterior retaining
wall footings should not be included in passive pressure calculations.
ACTIVE PRESSURE: The active soil pressure for the design of unrestrained earth retaining
structures with level backfills may be assumed to be equivalent to the pressure of a fluid weighing
32 pounds per cubic foot. For restrained walls, a soil pressure of 50 pcf should be assumed. For 2:1
(horizontal to vertical) sloping backfills, 14 pcf should be added to the preceding values. These
pressures do not consider any surcharge. If any are anticipated, this office should be contacted for
the necessary increase in soil pressure. This value assumes a granular and drained backfill
condition. Waterproofing details should be provided by the project architect. A wall drainage detail
is provided on the attached Plate Number 9.
BACKFILL: All backfill soils should be compacted to at least 90% relative compaction.
Expansive or clayey soils should not be used for backfill material. It is anticipated that backfill
SCS &T 9121003 February 11, 1991 Page 10
soils will have to be imported to the site. The wall should not be backfilled until the masonry has
reached an adequate strength.
FACTOR OF
SAFETY: The above values, with the exception of the allowable soil bearing
pressure, do not include a factor of safety. Appropriate factors of safety should be incorporated into
the design to prevent the walls from overturning and sliding.
LIMITATIONS
REVIEW, OBSERVATION AND TESTING
The recommendations presented in this report are contingent upon our review of final plans and
specifications. Such plans and specifications should be made available to the geotechnical engineer
and engineering geologist so that they may review and verify their compliance with this report and
with Chapter 70 of the Uniform Building Code.
It is recommended that Southern California Soil & Testing, Inc. be retained to provide continuous
1 soil engineering services during the earthwork operations. This is to verify compliance with the
design concepts, specifications or recommendations and to allow design changes in the event that
subsurface conditions differ from those anticipated prior to start of construction.
UNIFORMITY OF CONDITIONS
The recommendations and opinions expressed in this report reflect our best estimate of the project
requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface
exploration locations and on the assumption that the soil conditions do not deviate appreciably from
those encountered. It should be recognized that the performance of the foundations and /or cut and
fill slopes may be influenced by undisclosed or unforeseen variations in the soil conditions that may
occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report
that may be encountered during site development should be brought to the attention of the
geotechnical engineer so that he may make modifications if necessary.
SCS &T 9121003 February 11, 1991 Page 11
CHANGE IN SCOPE
This office should
be advised of any changes in the project scope or proposed site grading so that
we may determine if the recommendations contained herein are appropriate. This should be verified
in writing or modified by a written addendum.
TIME LIMITATIONS
The findings of this report are valid as of this date. Changes in the condition of a property can,
however, occur with the passage of time, whether they be due to natural processes or the work of
man on this or adjacent properties. In addition, changes in the Standards -of- Practice and /or
Government Codes may occur. Due to such changes, the findings of this report may be invalidated
wholly or in part by changes beyond our control. Therefore, this report should not be relied upon
after a period of two years without a review by us verifying the suitability of the conclusions and
recommendations.
PROFESSIONAL STANDARD
In the performance of our professional services, we comply with that level of care and skill
ordinarily exercised by members of our profession currently practicing under similar conditions and
in the same locality. The client recognizes that subsurface conditions may vary from those
encountered at the locations where our borings, surveys, and explorations are made, and that our
data, interpretations, and recommendations are based solely on the information obtained by us. We
will be responsible for those data, interpretations, and recommendations, but shall not be
responsible for the interpretations by others of the information developed. Our services consist of
professional consultation and observation only, and no warranty of any kind whatsoever, express or
implied, is made or intended in connection with the work performed or to be performed by us, or by
our proposal for consulting or other services, or by our furnishing of oral or written reports or
findings.
i
E
1
1
SCS &T 9121003 February 11, 1991 Page 12
a
CLIENT'S RESPONSIBILITY
It is the responsibilit p y of Mr. Jim Chambers, or his representatives to ensure that the information
and recommendations contained herein are brought to the attention of the structural engineer and
architect for the project and incorporated into the project's plans and specifications. It is further his
responsibility to take the necessary measures to ensure that the contractor and his subcontractors
carry out such recommendations during construction.
FIELD EXPLORATIONS
Two subsurface explorations were made at the locations indicated on the attached Plate Number 1
on January 23, 1991. These explorations consisted of hand dug test pits. In addition we logged an
existing cut slope. The field work was conducted under the observation of our engineering geology
personnel.
The explorations were carefully logged when made. These logs are presented on the following
Plates Number 2 and 4. The soils are described in accordance with the Unified Soils Classification
System as illustrated on the attached simplified chart on Plate 3. In addition, a verbal textural
description, the wet color, the apparent moisture and the density or consistency are provided. The
density of granular soils is given as either very loose, loose, medium dense, dense or very dense.
The consistency of silts or clays is given as either very soft, soft, medium stiff, stiff, very stiff, or
hard.
Disturbed and "undisturbed" samples of typical and representative soils were obtained and returned
to the laboratory for testing.
LABORATORY TESTING
Laboratory tests were performed in accordance with the generally accepted American Society for
Testing and Materials (ASTM) test methods or suggested procedures. A brief description of the
tests performed is presented below:
' SCS &T 9121003 February 11, 1991
Page 13
' a) CLASSIFICATION: Field classifications were verified in the laboratory by visual
examination. The final soil classifications are in accordance with the Unified Soil
1 Classification System.
b) MOISTURE - DENSITY: In -place moisture contents and dry densities were
determined for representative soil samples. This information was an aid to
classification and permitted recognition of variations in material consistency with
depth. The dry unit weight is determined in pounds per cubic foot, and the in -place
moisture content is determined as a percentage of the soil's dry weight. The results
r are summarized in the pit logs.
' c) GRAIN SIZE DISTRIBUTION: The grain size distribution was determined for
representative samples of the native soils in accordance with ASTM C 117, C 136 and
D422. The results of these tests are presented on Plate Number 5.
d) COMPACTION TEST: The maximum dry density and optimum moisture content
of typical soils were determined in the laboratory in accordance with ASTM
' Standard Test D- 1557 -78, Method A. The results of these tests are presented herein.
Sample Number: P 1 @ 2' -3'
Maximum Dry Density: 107.0 pcf
Optimum Moisture Content: 16.6%
g) DIRECT SHEAR TESTS: Direct shear tests were performed to determine the
failure envelope based on yield shear strength. The shear box was designed to
accommodate a sample having a diameter of 2.375 inches or 2.50 inches and a
' height of 1.0 inch. Samples were tested at different vertical loads and a saturated
moisture content. The shear stress was applied at a constant rate of strain of
approximately 0.05 inches per minute. The results of these tests are presented on
attached Plate Number 6.
SUBSURFACE EXPLORATION LEGEND
' UNIFIED SOIL CLASSIFICATION CHART
' SOIL DESCRIPTION GROUP SYMBOL TYPICAL NAMES
I. COARSE GRAINED, more than half
' of material is larger than
No. 200 sieve size.
GRAVELS CLEAN GRAVELS GW Well graded gravels, gravel -
oA re than half of sand mixtures, little or no
coarse fraction is fines.
' larger than No. 4 GP Poorly graded gravels, gravel
sieve size but sand mixtures, little or no
smaller than 3 ". fines.
GRAVELS WITH FINES GM Silty gravels, poorly graded
(Appreciable amount gravel- sand -silt mixtures.
of fines) GC Clayey gravels, poorly
graded gravel -sand, clay
mixtures.
SANDS CLEAN SANDS SW Well graded sand, gravelly
More than half of sands, little or no fines.
coarse fraction is SP Poorly graded sands, gravelly
smaller than No. 4 sands, little or no fines.
' sieve size.
SANDS WITH FINES SM Silty sands, poorly graded
(Appreciable amount sand and silty mixtures.
of fines) SC Clayey sands, poorly graded
sand and clay mixtures.
II. FINE GRAINED, more than
half of material is smaller
than No. 200 sieve size.
' SILTS AND CLAYS ML Inorganic silts and very
fine sands, rock flour, sandy
silt or cl�ey -silt -sand
mixtures with slight plan-
, ticity.
Liquid Limit CL Inorganic clays of low to
less than 50 medium plasticity, gravelly
clays, sandy clays, silty
' clays, lean clays.
OL Organic silts and organic
silty clays or low plasticity.
SILTS AND CLAYS MH Inorganic silts, micaceous
or diatomaceous fine sandy
or silty soils, elastic
silts.
Liquid Limit CH Inorganic clays of high
greater than 50 plasticity, fat clays.
' OH Organic clays of medium
to high plasticity.
HIGHLY ORGANIC SOILS PT Peat and other highly
' organic soils.
Water level at time of excavation CK — Undisturbed chunk sample
or as indicated BG — Bulk sample
US — Undisturbed, driven ring sample SP — Standard penetration sample
' or tube sample
SOUTHERN CALIFORNIA CHAMBERS RESIDENCE
SOIL S TESTING,INC. BY: DBA DATE: 2 -08 -91
' J08 NUMBER: 9121003 Plate No 3
•- } _
PIT NUMBER 1 W W W ca ¢= W i
..
yd W ELEVATION < a L LU G a � Z
' p 41 < d 0 d Z Q 0 2 W d
0 DESCRIPTION � v O ¢ s v cr p
0 O U
1 SM FILL, Brown, SILTY SAND Dry to Medium
1 Humid Dense
BG SM TOPSOIL, Brown, SILTY SAND Hu Medium
mid Me
1 2 Dense
BG SP/ TORREY SANDSTONE, Grey Humid Dense
3
CK SM White, Slightly SILTY SAND
' Pit Ended at 5'
1
P IT NUMBER 2
0
1 SM SLOPEWASH, Brown, SILTY Humid Medium
1 SAND Dense
' BG SP/ TORREY SANDSTONE, Grey Humid Dense
CK SM White to Tan, Slightly
2 SILTY SAND
Pit Ended at 2'
1
1
1
. SQ SOUTHERN CALIFORNIA PROJECT CHAMBERS RESIDENCE
' T SOIL 8. TESTING INC LOGGED B r: MF DATE LOGGED 1 -23 -91
.
JOB NUMBER: 9121003 PLATE NUMBER: 4
1
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SOUTHERN CALIFORNIA CHA RESIDENCE
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11
1
S CALIF CHAMBER RESI
9121003 • •
lion NUMBER
SLOPE STABILITY CALCULATIONS
Janbu's Simplified Slope Stability Method
,,C (p=WHC an FS =Ncf( C )
' Assume Homogeneous Strength Parameters throughout the slope
' 0 (0 ) C(Psf) W (Pcf) Incl. H (ft) FS
Permanent Cut 40 200 106 2:1 20 2.8
Slopes
' Temporary Cut 36 700 125 2:1 20 3.9 Slope 40 200 106 0.75:1 30 1.3
r
Where: 0 = Angle of Internal Friction
C = Cohesion (psf)
W = Unit weight of Soil (pcf)
H = Height of Slope (ft)
FS = Factor of Safety
' SOUTHERN CALIFORNIA CHAMBERS RESIDENCE
SOIL S TESTING, INC. Br: DBA DATE: 2-08-91
JOB NUMBER: 9121003 Plate No. 7
TRANSVERSE
JOINTS
T LONGITUDINAL x
JOINTS W (ft) TRANSVERSE
3 W /2
Y L
3' W (ft) - JOINT 3'�� W
SPACING W/2 W/2
SLAB ON GRADE 10 FEET OR GREATER IN WIDTH SLAB ON GRADE 5 FEET TO 10 FEET IN WIDTH
NOTE: 1. 'W' SHOULD NOT EXCEED 15 FEET.
2. JOINT PATTERN SHOULD BE NEARLY SQUARE.
TOOLED OR SAWED JOINT
*T /4
PER RE
(r MIN. COVER)
*T
*T = THICKNESS PER REPORT
CONTROL JOINT DETAIL
NO SCALE
e SQ> SOUTHERN CALIFORNIA PROJECT: CHAMBERS RESIDENCE
SOIL & TESTING, INC BY: DBA DATE: 2 -13-91
JOB NUMBER: 9121003 Plate No. 8
f I
' -1 % SLOPE MINIMUM _ 6 'N•
6" MAX.
' o • ; ,° WATERPROOF BACK OF WALL PER
°. ARCHITECT'S SPECIFICATIONS
,o
' • o • 3/4 INCH CRUSHED ROCK OR MIRADRAIN
o'
6000 OR EQUIVALENT
•o
o • °. GEOFABRIC BETWEEN ROCK AND SOIL
o °
o, •°
o • TOP OF GROUND
° OR CONCRETE SLAB
6' FmNl.
o °
MINIMUM
4 INCH DIAMETER
PERFORATED PIPE
RETAINING WALL
SUBDRAIN DETAIL
NO SCALE
SOUTHERN CALIFORNIA CHAMBERS RESIDENCE
' SOIL & TESTING, INC. sr: DBA OATS: 2 -13 -91
' JOB Nummall: 9121003 Plate No. 9
PROPOSED CHAMBERS RESIDENCE, 1375 TRABERT RANCH ROAD, ENCINITAS
RECOMMENDED GRADING SPECIFICATIONS - GENERAL PROVISIONS
' GENE
RAL INTENT
The intent of these specifications is to
P establish procedures for clearing, compacting natural ground,
preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the
accepted plans. The recommendations contained in the preliminary geotechnical investigation report
and /or the attached Special Provisions are a part of the Recommended Grading Specifications and shall
supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be
used in conjunction with the geotechnical report for which they are a part. No deviation from these
specifications will be allowed, except where specified in the geotechnical report or in other written
communication signed by the Geotechnical Engineer.
'
OBSERVATION AND TESTING
Southern California Soil and Testing, Inc., shall be retained as the Geotechnical Engineer to observe and
test the earthwork in accordance with these specifications. It will be necessary that the Geotechnical
Engineer or his representative provide adequate observation so that he may provide his opinion as to
whether or not the work was accomplished as specified. It shall be the responsibility of the contractor to
assist the Geotechnical Engineer and to keep him appraised of work schedules, changes and new
ew
information and data so that he may provide these opinions. In the event that any unusual conditions not
covered by the special provisions or preliminary geotechnical report are encountered during the grading
operations, the Geotechnical Engineer shall be contacted for further recommendations.
If
in the opinion of the Geotechnical Engineer, substandard conditions are encountered, such as
questionable or unsuitable soil, unacceptable moisture content, inadequate compaction, adverse weather,
etc.; construction should be stopped until the conditions are remedied or corrected or he shall
recommend rejection of this work.
(R -9/89)
i
SCS &T 9121003 February 12, 1991 Appendix, Page age 2
Tests used to determine the degree of compaction should be performed in accordance with the following
American Society for Testing and Materials test methods:
Maximum Density & Optimum Moisture Content - ASTM D- 1557 -78.
' Density of Soil In -Place - ASTM D- 1556 -64 or ASTM D -2922.
All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM
testing procedures.
' PREPARATION OF AREAS TO RECEIVE FILL
All vegetation, brush and debris derived from clearing operations shall be removed, and legally disposed
of. All areas disturbed by site grading should be left in a neat and finished appearance, free from
unsightly debris.
After clearing or benching the natural ground, the areas to be filled shall be scarified to a depth of 6
inches, brought to the proper moisture content, compacted and tested for the specified minimum degree
' of compaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground
which is defined as natural soils which possesses an in -situ density of at least 90 percent of its maximum
dry density.
When the slope of the natural ground receiving till exceeds 20 percent (5 horizontal units to 1 vertical
r unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent
formational soils. The lower bench shall be at least 10 feet wide or 1 -1/2 times the equipment width,
' whichever is greater, and shall be sloped back into the hillside at a gradient of not less than two (2)
percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be
compacted prior to receiving fill as specified herein for compacted natural ground. Ground slopes flatter
than 20 percent shall be benched when considered necessary by the Geotechnical Engineer.
Any abandoned buried structures encountered during u tng grading operations must be totally removed. All
' underground utilities to be abandoned beneath any proposed structure should be removed from within 10
feet of the structure and properly capped off. The resulting depressions from the above described
procedures should be backfilled with acceptable soil that is compacted to the requirements of the
(R -9/89)
' SCS &T 9121003 February 12, 1991 Appendix, Page age 3
Geotechnical Engineer. This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach
lines, storm drains and water lines. Any buried structures or utilities not to be abandoned should be
' brought to the attention of the Geotechnical Engineer so that he may determine if any special
recommendation will be necessary.
r All
water wells which will be abandoned should be backfilled and capped in accordance to the
' requirements set forth by the Geotechnical Engineer. The top of the cap should be at least 4 feet below
finish grade or 3 feet below the bottom of footing whichever is greater. The type of cap will depend on
the diameter of the well and should be determined by the Geotechnical Engineer and /or a qualified
Structural Engineer.
FILL MATERIAL
Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of
vegetable matter and other deleterious substances. Granular soil shall contain sufficient fine material to
fill the voids. The definition and disposition of oversized rocks and expansive or detrimental soils are
covered in the geotechnical report or Special Provisions. Expansive soils, soils of poor gradation, or soils
r with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill
material, but only with the explicit consent of the Geotechnical Engineer. Any import material shall be
' approved by the Geotechnical Engineer before being brought to the site.
PLACING Al COMPACTION OF FILL
1
Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in
compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the
compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall
be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size
to economically compact the layer. Compaction equipment should either be specifically designed for soil
' compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in
either the Special Provisions or the recommendations contained in the preliminary geotechnical
investigation report.
r
(R -9/89)
SCS &T 9121003 February 12, 1991 Appendix, Page 4
P � 8
When the structural fill material includes rocks, no rocks will be allowed to nest and all voids must be
carefully filled with soil such that the minimum degree of compaction recommended in the Special
Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in
non - structural fills is discussed in the geotechnical report, when applicable.
Field observation and compaction p tests to estimate the degree of compaction of the fill will be taken by
the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the
Geotechnical Engineer's discretion. When the compaction test indicates that a particular layer is at less
than the required degree of compaction, the layer shall be reworked to the satisfaction of the
Geotechnical Engineer and until the desired relative compaction has been obtained.
Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction
by sheepsfoot rollers shall be at vertical intervals of not greater than four feet. In addition, fill slopes at a
ratio of two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be
over -built and cut -back to finish contours after the slope has been constructed. Slope compaction
operations shall result in all fill material six or more inches inward from the finished face of the slope
having a relative compaction of at least 90 percent of maximum dry density or the degree of compaction
1 specified in the Special Provisions section of this specification. The compaction operation on the slopes
shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be stable
surficially stable.
Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to
' determine if the required compaction is being achieved. Where failing tests occur or other field problems
arise, the Contractor will be notified that day of such conditions by written communication from the
Geotechnical Engineer or his representative in the form of a daily field report.
If the method of achieving the required slope compaction selected by the Contractor fails to produce the
necessary results, the Contractor shall rework or rebuild such slopes until the required degree of
compaction is obtained, at no cost to the Owner or Geotechnical Engineer.
r
(R -9/89)
SCS &T 9121003 February 12, 1991 Appendix, Page 5
t CUT SLOPES
The Engineering Geologist shall inspect cut slopes excavated in rock or lithified formational material
during the grading operations at intervals determined at his discretion. If any conditions not anticipated in
the preliminary report such as perched water, seepage, lenticular or confined strata of a potentially
adverse nature, unfavorably inclined bedding, joints or fault planes are encountered during grading, these
conditions shall be analyzed by the Engineering Geologist and Soil Engineer to determine if mitigating
measures are necessary.
Unless otherwise specified in the geotechnical report, no cut slopes shall be excavated higher or steeper
than that allowed by the ordinances of the controlling governmental agency.
ENGINEERING OBSERVATION
Field observation by the Geotechnical Engineer or his representative shall be made during the filling and
compacting operations so that he can express his opinion regarding the conformance of the grading with
acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative
or the observation and testing shall not release the Grading Contractor from his duty to compact all fill
material to the specified degree of compaction.
SEASON LIMITS
Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain,
tilling operations shall not be resumed until the proper moisture content and density of the fill materials
can be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before
acceptance of work.
RECOMMENDED GRADING SPECIFICATIONS - SPECIAL PROVISIONS
RELATIVE COMPACTION: The minimum degree of
g compaction to be obtained in compacted natural
ground, compacted fill, and compacted backfill shall be at least 90 percent. For street and parking lot
subgrade, the upper six inches should be compacted to at least 95 percent relative compaction.
(R -9/89)
SCS &T 9121003 February 12, 1991 Appendix, Page 6
EXPANSIVE SOILS: Detrimentally expansive soil is defined as clayey soil which has an expansion
index of 50 or greater when tested in accordance with the Uniform Building Code Standard 29 -C.
OVERSIZID
MATERIAL: Oversized fill material is generally defined herein as rocks or lumps of soil
over 6 inches in diameter. Oversize materials should not be placed in fill unless recommendations of
placement of such material is provided by the geotechnical engineer. At least 40 percent of the fill soils
1 shall pass through a No. 4 U.S. Standard Sieve.
TRANSITION LOTS: Where transitions between cut and fill occur within the proposed building pad,
the cut portion should be undercut a minimum of one foot below the base of the proposed footings and
recompacted as structural backfill. In certain cases that would be addressed in the geotechnical report,
special footing reinforcement or a combination of special footing reinforcement and undercutting may be
required.
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(R -9/89)
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P ATE #1B
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