HomeMy WebLinkAboutCDP 2017-0064; SLOWIK ADU; GEOTECHNICAL REPORT UPDATE; 2017-08-08EAST COUNTY SOIL CONSULTATION
AND ENGINEERING, INC.
10925 HARTLEY ROAD, SUITE "I"
SANTEE, CALIFORNIA 92071
619 258-7901
FAX 619 258-7902
Sharon Slowik
3960 Sunnyhill Drive
Carlsbad, California 92008
Subject: Geotechnical Report Update
Proposed New Primary Residence
3960 Sunnyhill Drive
City of Carlsbad, California 92008
August 8, 2017
Project No. 03-1106H6(A)
Reference: "Limited Site Investigation, Proposed New Primary Residence, 3960 Sunnyhill
Drive, City of Carlsbad, California", Project No. 03-l 106H6(A), Prepared by East
County Soil Consultation and Engineering, Inc., Dated April 21, 2003.
Dear Mr. & Mrs. Slowik:
In accordance with your request, we have reviewed the referenced geotechnical report and visited
the site on August 7, 2017. The proposed building pad was found as described in the referenced
geotechnical report. Therefore, the recommendations provided in the referenced geotechnical
report are still valid for the proposed development. However, to be in accordance with the
present guidelines for geotechnical reports, the following additional recommendations may be
incorporated into the project design and construction.
SEISMICITY
Regional Seismicity
Generally, Seismicity within California can be attributed to the regional tectonic movement
taking place along the San Andreas Fault Zone, which includes the San Andreas Fault and most
parallel and subparallel faults within the state. The portion of southern California where the
subject site is located is considered seismically active. Seismic hazards are attributed to
groundshaking from earthquake events along nearby or more distant Quaternary faults. The
primary factors in evaluating the effect an earthquake has on a site are the magnitude of the
event, the distance from the epicenter to the site and the near surface soil profile.
According to the Fault-Rupture Hazard Zones Act of 1994 (revised Alquist-Priolo Special Studies
Zones Act), quaternary faults have been classified as "active" faults, which show apparent surface
rupture during the last 11,000 years (i.e., Holocene time). "Potentially-active" faults are those faults
with evidence of displacing Quaternary sediments between 11,000 and 1.6 million years old.
PAUL & SHARON SLOWIK/ 3960SUNNYHILL DRIVE ROJECT NO. 03-l 106H6(A)
Seismic Analysis
Based on our evaluation, the closest known "active" fault is the Rose Canyon Fault located
approximately 4.4 kilometers (2.74 miles) to the west. The Rose Canyon Fault is the design fault
of the project due to the predicted credible fault magnitude and ground acceleration.
The Seismicity of the site was evaluated utilizing the 2008 National Hazard Maps from the
USGS website and Seed and Idriss methods for active Quaternary faults within a 50-mile radius
of the subject site. The site may be subjected to a Maximum Probable Earthquake of 6.9
Magnitude along the Rose Canyon Fault, with a corresponding Peak Ground Acceleration of
0.46g. The maximum Probable Earthquake is defined as the maximum earthquake that is
considered likely to occur within a I 00-year time period.
The effective ground acceleration at the site is associated with the part of significant ground
motion, which contains repetitive strong-energy shaking, and which may produce structural
deformation. As such, the effective or "free field" ground acceleration is referred to as the
Repeatable High Ground Acceleration (RHGA). It has been determined by Ploessel and Slosson
(1974) that the RHGA is approximately equal to 65 percent of the Peak Ground Acceleration for
earthquakes occurring within 20 miles of a site. Based on the above, the calculated Credible
RHGA at the site is 0.30g.
2016 CBC Seismic Design Criteria
A review of the active fault maps pertaining to the site indicates the location of the Rose Canyon
Fault Zone approximately 9.4 km (5.9 miles) to the west. Ground shaking from this fault or one
of the major active faults in the region is the most likely happening to affect the site. With
respect to this hazard, the site is comparable to others in the general area. The proposed single-
family residence should be designed in accordance with seismic design requirements of the 2016
California Building Code or the Structural Engineers Association of California using the
following seismic design parameters:
P~TER VALUE 2016 CBC & ASCE 7 REFERENCES
Site Class D Table 20.3-1/ ASCE 7, Chapter 20
Mapped Spectral Acceleration For Short Periods, 1.113g Figure 1613.3.1(1)
s.
Mapped Spectral Acceleration For a I-Second 0.428g Figure 1613.3.1(2)
Period, S1
Site Coefficient, Fa 1.055 Table 1613.3.3(1)
Site Coefficient, F v 1.572 Table 1613.3.3(2)
Adjusted Max. Considered Earthquake Spectral 1.174g Equation 16-3 7
Response Acceleration for Short Periods, SMs
Adjusted Max. Considered Earthquake Spectral 0.673g Equation l 6-3 8
Response Acceleration for I -Second Period, SM 1
5 Percent Damped Design Spectral Response 0.783g Equation 16-39
Acceleration for Short Periods, Sos
5 Percent Damped Design Spectral Response 0.448g Equation 16-40
Acceleration for I-Second Period, S01
2
PAUL & SHARON SLOWIK/ 3960SUNNYH/LL DRIVE ROJECT NO. 03-1106H6(A)
Geologic Hazard Assessment
Ground Rupture
Ground rupture due to active faulting is not considered likely due to the absence of known fault
traces within the vicinity of the project; however, this possibility cannot be completely ruled out.
The unlikely hazard of ground rupture should not preclude consideration of "flexible" design for
on-site utility lines and connections.
Liquefaction
Liquefaction involves the substantial loss of shear strength in saturated soils, usually sandy soils
with a loose consistency when subjected to earthquake shaking. Based on the absence of shallow
groundwater and consistency of the bedrock material, it is our opinion that the potential for
liquefaction is very low.
Landsliding
There is no indication that landslides or unstable slope conditions exist on or adjacent to the
project site. There are no obvious geologic hazards related to landsliding to the proposed
development or adjacent properties.
Tsunamis and Seiches
The site is not subject to inundation by tsunamis due to its elevation and distance to the ocean.
The site is also not subject to seiches (waves in confined bodies of water).
PERMANENT SLOPES
Permanent cut and fill slopes are anticipated to be less than 10 feet in height and may be
constructed no steeper than 2: 1 (horizontal to vertical). These slopes are anticipated to be grossly
stable. It is recommended that drought resistant vegetation be planted as soon as practical to
enhance the stability of the slope surfaces.
TEMPORARY SLOPES
For the excavation of foundations and utility trenches, temporary vertical cuts to a maximum height
of 4 feet may be constructed in fill or natural soil. Any temporary cuts beyond the above height
constraints should be shored or further laid back following a I: I (horizontal to vertical) slope ratio.
OSHA guidelines for trench excavation safety should be implemented during construction.
PRESATURATION OF SLAB SUBGRADE
Due to the granular characteristics of the subgrade soils, presoaking of subgrade prior to concrete
pour is not required. However, subgrade soils in areas receiving concrete should be watered
prior to concrete placement to mitigate any drying shrinkage, which may occur following site
preparation and foundation excavation.
3
PAUL & SHARON SLOWIK/ 3960SUNNYHILL DRIVE ROJECT NO.03-1106H6(A)
DRAINAGE
Adequate measures should be undertaken to finish grade the site after the structure and other
improvements are in place, such that the drainage water within the site and adjacent properties is
directed away from the foundations, footings, floor slabs and the tops of slopes via rain gutters,
downspouts, surface swales and subsurface drains towards the natural drainage for this area. In
accordance with the 2016 California Building Code, a minimum gradient of 2 percent is
recommended in hardscape areas adjacent to the structure. In earth areas, a minimum gradient of
5 percent away from the structure for a distance of at least 10 feet should be provided. If this
requirement cannot be met due to site limitations, drainage can be done through a swale in
accordance with Section 1804.4 of the 2016 California Building Code. Earth swales should have
a minimum gradient of 2 percent. Drainage should be directed to approved drainage facilities.
Proper surface and subsurface drainage will be required to minimize the potential of water
seeking the level of the bearing soils under the foundations, footings and floor slabs, which may
otherwise result in undermining and differential settlement of the structure and other
improvements.
If we can be of any further assistance, please do not hesitate to contact our office.
Respectfully submitted,
Mamadou Saliou Diallo, P.E.
RCE 54071, GE 2704
MSD/md
4
EAST COUNTY SOIL CONSULTATION
AND ENGINEERING, INC.
10925 HARTLEY ROAD, SUITE "I"
SANTEE, CALIFORNIA 92071
(619) 258-7901
Fax (619) 258-7902
Mr. & Mrs. Paul Slowik
3960 Sunnyhill Drive
Carlsbad, California 92008
Subject: Soil Bearing Value Recommendation
Proposed Second Story Addition
3960 Sunnyhill Drive
City of Carlsbad, California
Dear Mr. & Mrs. Slowik:
July 16, 2003
Project No. 03-1106H6
In accordance with your request, we have performed laboratory
testing on a representative sample of the foundation soils to
provide a soil bearing value for the design of a second story
addition over the south side of the existing residence located at
3960 Sunnyhill Drive, in the City of Carlsbad, California.
The foundation soils associated with the Terrace deposits
Formation (Qt2 ) consist of brown, silty fine-grained sand (SM)
exhibiting a very low potential for expansion (Expansion Index =
zero). The footing of the original house was 12 inches wide and 12
inches deep, while the footing of the previous single story
addition to the east was 12 inches wide and 18 inches deep.
SOIL BEARING VALUE
An allowable soils bearing value of 1500 pounds per square foot
may be used for the design of continuous and spread footings at
least 12 inches wide and founded a minimum of 12 inches into the
dense native soils. This value may be increased by 20 percent for
each additional foot of depth or width to a maximum value of 4500
lb/ft2, as set forth in the 1997 Edition of the Uniform Building
Code, Table No. 18-1-A.
SLOWIK PROJECT NO 03-1106H6
GEOLOGIC HAZARDS
A review of the available geological literature pertaining to the
site indicates the existence of the Rose Canyon Fault Zone
approximately 9. 0 Km to the west. Ground shaking from this fault
or one of the major active faults in the region is the most likely
happening to affect the site. With respect to this hazard, the
site is comparable to others in the general area.
The proposed second story addition should be designed in
accordance with seismic design requirements of the 1997 Uniform
Building Code or the Structural Engineers Association of
California using the following seismic design parameters:
PARAMETER VALUE UBC REFERENCE
Seismic Zone Factor, Z 0.40 Table 16-I
Seismic Source B Table 16-U
Soil Profile Type So Table 16-J
Near-Source Factor, Na 1.0 Table 16-S
Near-Source Factor, Nv 1.1 Table 16-T
Seismic Coefficient, Ca 0.44 Table 16-Q
Seismic Coefficient, Cv 0.70 Table 16-R
Based on the absence of shallow groundwater and consistency of the
Terrace Deposits, it is our opinion that the potential for
liquefaction is very low.
If we can be of any further assistance, please do not hesitate to
contact our office.
Laboratory test results and references are parts of this report.
Respectfully submitted,
~ '/,-, ~\ .~ -'rft
/~ <'\()'u ~'-I)/,. ~
;::._'>J ~'\I ~
No.C054071
L ~ ·,J.,
' Mamadou Saliou Diallo, P.E.
RCE 54071
MSD/md
2
SLOWIK PROJECT NO 03-1106H6
PAGE L-1
LABO RA TORY TEST RESULTS
RES UL TS OF EXP ANSI ON INDEX TEST
An expansion test in conformance with ASTM D4829 was performed on a representative sample of
on-site soils to determine volumetric change characteristics with change in moisture content. The
recorded expansion of the sample is presented as follows:
INITIAL
MOISTURE
CONTENT%
8.4
SATURATED
MOISTURE
CONTENT%
16.5
INITIAL DRY
DENSITY
LB.ICU. FT.
115.5
EXPANSION
INDEX
0
RESULTS OF PARTICLE SIZE ANALYSIS
. ;. U.S. Standard
Sieve Size
. ASTM D-422)
l"
1/2"
3/8"
#4
#8
#16
#30
#60
#100
#200
uses
3
100
99
97
94
85
41
26
21
SM
SLOWIK PROJECT NO 03-1106H6
REFERENCES
1. "1997 Edition, Uniform Building Code, Volume 2, Structural
Engineering and Design Provisions".
2. "Maps of Known Active Fault Near-Source Zones in California and
Adjacent Portions of Nevada", Page 0-37, used with the 1997
Edition of the Uniform Building Code, Published by International
Conference of Building Officials.
3. "Geologic Maps of the Northwestern Part of San Diego County,
California. Plate No. 1, Geologic Maps of the Oceanside, San Luis
Rey and San Marcos 7.5' Quadrangles", by Siang S. Tan and Michael
P. Kennedy, 1996.
4
EAST COUNTY SOIL CONSULTATION
AND ENGINEERING, INC.
10925 HARTLEY ROAD, SUITE "I"
SANTEE, CALIFORNIA 92071
(619) 258-7901
Fax 258-7902
Mr. & Mrs. Paul Slowik
3960 Sunnyhill Drive
Carlsbad, California 92008
April 21, 2004
Project No. 03-1106H6(A)
Subject: Limited Site Investigation
Proposed New Primary Residence
3960 Sunnyhill Drive
City of Carlsbad, California
Dear Mr. & Mrs. Slowik:
In accordance with your request, we have performed a limited
investigation of the soil conditions at the subject site. The
investigation was undertaken to provide the soil engineering
criteria for site grading and recommend an appropriate foundation
system for the proposed residence.
Our investigation has found that the proposed building pad is
underlain by undocumented fill soils, topsoil and colluvium to a
maximum depth of approximately 5.0 feet. Below the colluvium,
medium dense to dense sandstone of the Terrace Deposits Formation
was encountered to the maximum explored depth of 5.5 feet.
It is our
provided
opinion that the
the recommendations
construction.
Respectfully submitted,
Mamadou Saliou Diallo, P.E
RCE 54071
proposed
herein
development is
are implemented
feasible
during
SLOWIK PROJECT NO.03-1106H6(A)
INTRODUCTION
This is to present the findings and conclusions
investigation for a proposed two-story, single-family
be located on the east side of Sunnyhill Drive, in
Carlsbad, California.
of a soil
residence to
the City of
The objectives of the investigation were to evaluate the existing
soils conditions and provide recommendations for the proposed
construction.
In order to accomplish these objectives,
borings were drilled to a maximum depth of
and loose bag samples were obtained, and
performed.
SITE DESCRIPTION AND PROPOSED CONSTRUCTION
two (2)
5.5 feet;
laboratory
exploratory
undisturbed
tests were
The subject site is located on the east side of Sunnyhill Drive,
in the City of Carlsbad, California. It is a previously graded cut
and fill lot that was developed with a single-story house. This
residence will remain as a granny flat. The area of the proposed
second dwelling unit was an elevated pad approximately 15 feet
above existing grade. Vegetation consisted of trees, shrubs and
grass. It is our understanding the proposed construction will
consist of a two-story, wood-framed structure to be utilized as a
primary residence. The plot plan, Plate No. 1 provides a layout of
the proposed development.
FIELD INVESTIGATION
On March 5, 2004, two (2) exploratory borings were drilled to a
maximum depth of 5.5 feet below existing grade with a hand auger.
The approximate locations of the borings are shown on the attached
Plate No. 1, entitled "Location of Exploratory Borings". A
continuous log of the soils encountered was recorded at the time
of excavation and is shown on Plate No. 2 entitled "Summary
Sheet".
The soils were visually and texturally classified according to the
filed identification procedures set forth on the attached Plate
No. 3 entitled "Uniform Soil Classification Systemu.
2
SLOWIK PROJECT NO. 03-l 106H6(A)
SUBGRADE CONDITIONS
-Undocumented fill soils, topsoil and colluvium underlie the
proposed pad to a maximum depth of approximately five feet. These
soils generally consist of silty sand with a trace of clay and a
loose consistency. Dense sandstone of the Terrace Deposits
Formation was underlying the colluvium.
EXPANSIVE SOILS
An expansion index test was performed on a select sample of the
undocumented fill soils to determine volumetric change
characteristics with change in moisture content. An expansion
index of 14 indicates a very low expansion potential of the fill
soils.
GROUNDWATER
Groundwater was not
investigation. Static
greater than 100 feet.
proposed development.
GEOLOGIC HAZARDS
encountered during the course of our
groundwater is anticipated at a depth
We do not expect groundwater to affect the
A review of the available geological literature pertaining to the
site indicates the existence of the Rose Canyon Fault Zone
approximately 9.0 Km to the west. Ground shaking from this fault
or one of the major active faults in the region is the most likely
happening to affect the site. With respect to this hazard, the
site is comparable to others in the general area.
The proposed
accordance with
Building Code
California using
residential structure should be designed in
seismic design requirements of the 1997 Uniform
or the Structural Engineers Association of
the following seismic design parameters:
PARAMETER VALUE UBC REFERENCE
Seismic Zone Factor, Z 0.40 Table 16-I
Seismic Source B Table 16-U
Soil Profile Type So Table 16-J
Near-Source Factor, Na 1.0 Table 16-S
Near-Source Factor, Nv I.I Table 16-T
Seismic Coefficient, Ca 0.44 Table 16-Q
Seismic Coefficient, Cv 0.70 Table 16-R
,.,
.)
SLOWIK PROJECT NO.03-1106H6(A)
Based on the absence of shallow groundwater and consistency of the
Terrace Depostts Formation, it is our opinion that the potential
for liquefaction is very low.
CONCLUSIONS AND RECOMMENDATIONS
The following conclusions and recommendations are based upon the
analysis of the data and information obtained from our soil
investigation. .This includes visual inspection; field
investigation; laboratory testing and our general knowledge of the
soils native to the site. The site is suitable for the proposed
residential development provided the recommendations set forth are
implemented during construction.
GRADING AND EARTHWORK
Site grading should begin with clearing and grubbing, e.g. the
removal of vegetation and deleterious materials. Subgrade soils
extending to the Terrace Deposits Formation in the proposed
building pad should be overexcavated, moisture conditioned within
2 percent over optimum and compacted to a minimum of 90 percent
relative compaction. Proper keying and benching of the subgrade
along the adjacent slopes should be observed during the grading
operation, should the proposed footings be built on those slopes.
The actual depth and extent of removal should be evaluated in the
field at the time of excavation by a representative of this firm.
Grading should be performed in accordance with the attached
appendix A.
FOUNDATION AND SLAB
a. Continuous footings are suitable for use and should extend a
minimum of 18 inches for the two-story residence into the
compacted fill soils. These footings should be at least 15 inches
in width and reinforced with two #5 steel bars; one bar placed
near the top of the footings and the other bar placed near the
bottom of the footings.
b. Concrete floor slabs should be a minimum of 4 inches thick.
Reinforcement should consist of #3 bars placed at 16 inches on
center each way. Slab reinforcement should be placed within the
middle third of the slab by supporting the steel on chairs or
concrete blocks "dobies". The slab should be underlain by 2 inches
of clean sand over a 10-mil visqueen moisture barrier.
4
SLOWIK PROJECT NO. 03-1106H6(A)
The effect of concrete shrinkage will result in
virtually all concrete slabs. To reduce the extent of
the concrete should be placed at a maximum of 4 inch
minimum steel recommended is not intended to prevent
cracks.
cracks in
shrinkage,
slump. The
shrinkage
c. Where moisture sensitive floor coverings are anticipated over
the slab, the 10-mil plastic moisture barrier should be underlain
by a capillary break at least 2 inches thick, consisting of coarse
sand, gravel or crushed rock not exceeding 3/4 inch in size with
no more than 5 percent passing the #200 sieve.
d. An allowable soil bearing value of 1500 pounds per square foot
may be used for the design of continuous and spread footings
founded a minimum of 12 inches into the compacted fill soils. This
value may be increased by 20 percent for each additional foot of
width or depth to a maximum value of 4500 lb/ft2, as set forth in
the 1997 Edition of the Uniform Building Code, Table No. 18-1-A.
e. Lateral resistance to horizontal movement may be provided by
the soil passive pressure and the friction of concrete to soil. An
allowable passive pressure of 200 pounds per square foot per foot
of depth may be used. A coefficient of friction of 0.35 is
recommended. The soils passive pressure as well as the bearing
value may be increased by 1/3 for wind and seismic loading.
FOUNDATION SETBACK
Compacted fill soils that occur within 8 feet of the face of slope
possess poor lateral stability, even though they have been
certified with a relative compaction of 90 percent or better.
Proposed structures and other improvements that are located within
8 feet of the face of compacted fill slopes could suffer
differential moveme~t as a result of the poor lateral stability of
these soils. Therefore, foundations and footings for the proposed
structures or other improvements should be placed at least 8 feet
back from the top of these slopes. Foundations placed closer to
the top of slope than 8 feet should be deepened such that the
bottom of the foundation is at least 8 feet back from the face of
the slope.
5
SLOWIK PROJECT NO. 03-1106H6(A)
SETTLEMENT
Settlement of compacted fill soils is normal and should be
anticipated. Because of the type and thickness of the fill soil
and the light building load, the settlement should be within
acceptable limits.
UTILITY TRENCH EXCAVATIONS
Excavations for on-site utility trenches may be made vertically
for shallow depths and must be either shored or sloped at lH: lV
for depths greater than 4 feet. Utilities should be bedded and
backfilled with clean sand or approved granular soil to a depth of
at least one foot over the pipe. This backfill should be uniformly
watered and compacted to a firm condition for pipe support. The
remainder of the backfill should be on-site soils or non-expansive
imported soils, which should be placed in thin lifts, moisture
conditioned and compacted to at least 90 % relative compaction.
DRAINAGE
Adequate measures should be undertaken to properly finish grade
the site after the structures and other improvements are in place,
such that the drainage water within the site and adjacent
properties is directed away from the foundations, footings, floor
slabs and the tops of slopes via surface swales and subsurface
drains towards the natural drainage for this area. Proper surface
and subsurface drainage will be required to minimize the potential
of water seeking the level of the bearing soils under the
foundations, footings and floor slabs, which may otherwise result
in undermining and differential settlement of the structures and
other improvements.
6
SLOWIK PROJECT NO.03-1106H6(A)
LIMITS OF INVESTIGATION
The recommendations provided in this report pertain only to the
site investigated and based upon the assumption that the soil
conditions do not deviate from those disclosed in the borings. If
any variations or undesirable conditions are encountered during
construction, or if the proposed construction will significantly
differ from that planned at the present time, East County Soil
Consultation and Engineering, Inc. should be notified so that
supplemental recommendations can be provided.
Plates No. 1 through 3, Pages L-1 & L-2, References and Appendix A
are parts of this report.
Respectfully submitted,
' ~·---.
~ ~
No.C054071
Exp. \ t.-3,\ -
Mamadou Saliou Diallo
RCE 54071
MSD/md
,L
7
1J ( ~ ~
I 1~ ~ ~
EAST COUNTY SOIL CONSULTATION
& ENGINEERING, INC.
I 0925 HARTI..EY RD . SUITE I. SANTEE. CA 9207 I
(6 I 9) 258-790 I Fax (6 I 9) 258-7902
.. \l
fJ~tJ/}
ti! r· 1;.f.
DEPTH
Surface
1. 5'
3. 0'
4. 0'
5. 0'
SLOWIK PROJECT NO 03-l 106H6(A)
PLATE NO. 2
SUMMARY SHEET NO. 1
BORING NO. 1
SOIL DESCRIPTION
UNDOCUMENTED FILL (Quf)
tan, moist to wet, loose, silty,
sand with a trace of clay
" " " " "
TOPSOIL
brown, damp, loose, silty sand
with rootlets
COLLUVIUM (Qal)
brown, moist, loose, fine-grained
silty sand (SM)
TERRACE DEPOSITS (Qt4 )
tan, damp to moist, medium dense
to dense, silty sand (SM)
5.5' bottom of boring, no caving, no groundwater
boring backfilled 3/5/04
DEPTH
Surface
2 • 0 I
3.5'
BORING NO. 2
SOIL DESCRIPTION
UNDOCUMENTED FILL (Quf)
tan, moist to wet, loose, silty,
sand with a trace of clay
COLLUVIUM (Qal)
brown, moist, loose, fine-grained
silty sand (SM)
TERRACE DEPOSITS (Qt")
tan, damp to moist, medium dense
to dense, silty sand (SM)
4.0' bottom of boring, no caving, no groundwater
boring backfilled 3/5/04
8
y M
98.9 16.1
y M
103.0 10.5
!
MAJOR DIVISIONS SYMBOL DESCRIPTION
GW WELL GRADED GR.A VELS OR GR.A VEL· SAND
MIXTURES. LITTLE OR NO FINES
GRAVELS GP
(MORE THAN½ POORLY GRADED GR.A VELS OR GR.A VEL·SAND
OF COARSE MIXTURES, LITTLE OR NO FINES
FRACTION GM SILTY GR.A VELS, GRAVEL-SAND-SILT MIXTURES >NO. 4SIEVE
SIZE) COARSE GC
GRAINED SOILS CLAYEY GR.A VELS, GRA VEL·SA.i'ID-CLA Y MIXTURES
(MORE THAN ½ OF SOIL > S"\V NO. 200 SIEVE SIZE) WELL GRADED SANDS OR GRA YELL Y SANDS,
LITTLE OR NO FINES
SANDS SP
(MORE THAN½ POORLY GRADED SANDS OR GRA YELL Y SANDS,
OF COARSE LITTLE OR NO FINES
FRACTION SM
<NO. 4SIEVE SILTY SA.i'IDS, SIL T-SA.i'ID MIXTURES
SIZE)
SC CLAYEY SANDS, SAND-CU. Y MIXTURES
ML INORGANIC SIL TS A.'ID YER Y FINE SA.i'IDS, ROCK
SILTS & FLOUR, SIL TY OR CLAYEY FINE SANDS OR CLAYEY
SIL TS WITH SLIGHT PLASTICITY
CLAYS CL INORGA.i'IIC CLAYS OF LOW TO MEDIUM
LIQUID LIMIT PLASTICITY, GRA YELL Y CLAYS, SANDY CLAYS,
< 50 SIL TY CLAYS. LEAN CLAYS
FINE GRAINED OL
SOILS ORGANIC SILTS AND ORGA."'-IIC SILTY CLAYS OF
LOW PLASTICITY
(MORE THAN ½ OF SOIL < MH NO. 200 SIEVE SIZE) INORGA.'lIC SILTS, MICACEOUS OR DIATOMACEOUS SILTS & FINE SA.i'lDY OR SIL TY SOILS, ELASTIC SIL TS
CLAYS CH INORGA.'lIC CLAYS OF HIGH PL\STICITY, FAT LIQUID LIM!,
~50 CLAYS
OH ORGA.i'lIC CLAYS OF MEDIUM TO HIGH PLASTICITY,
ORGANIC SIL TY CLAYS. ORGANIC SIL TS
HIGHLY ORGANIC SOILS
I
Pt PEAT AND OTHER HIGHLY ORGA.i'IIC SOILS
CLASSIFICATION CHART (lJNIFIED SOIL CLASSIFICATION SYSTEM)
70 ,-----------,----..--------,
CL..\.SSIFICA TION R.\.NGE OF GR.\.IN SIZES I 50 1--.,..--...,...------t--,,,_ _______ _,. U.S. STANDARD I GR.\.IN SIZE IN I
SIEVE SIZE :'<IILLIMETERS _: 10 BOCLDERS I Above 12 Inches Above 305 ~ 1-----:--....,....--,-...c.--+----'--_;.__,,,.:::.....____,
COBBLES ! 1: Inches To 3 Inches I 305 To 76.2 ~ ,.c l--'-----'-----:1"-+--_;._-,,c. ___ ____,
GR.\ YEL I 3 Inches to No. 4 i i6.2 to 4. :'6 I "'
Coarse i 3 Inches to'~ Inch 1· 76.2 to 19. l ! § io
Fin.: \ ~1• [nch to No. 4 19 i to 4.76 I ;;
SA.\iD '.'Jo 4 to No. 200 4.76 to 0 0i'.l ~ :o l----'---,t:.--"----A----------1
Coarse No. 4 to No. l 0 4. i6 to 2.00
Medium No. l Oto No. 40 2.00 to 0.420
Fine No. 40 to No. 200 0.420 to IJ.0-:-4
SILT AND CL..\ Y I Bdow '.'Jo. 200 I Bdow () :T 4
GRAIN SIZE CHART
EAST COuNTY SOIL CONSlL T...\ TION
AND ENGINEERING, INC.
10925 HARTLEY RO . ..\D. SlITE "I'"
SANTEE. C...\LIFOR.'IL..\ no-:1
C.S.C.S. SOIL CLASSIFICATIO:'-i
'0 r~:::::::===;;,"-----t-----:------:--J
0 IO l!l !O 40 !O ;c 7'0 JO lC 1 CO
''Ct.,;•:J 'Mli '' -PL..\STIC-ITY-CHA°RT
SLOWIK PROJECT NO. 03-1106H6(A)
PLATE NO. 3
APRIL 21, 2004
SLOWIK PROJECT NO 03-1106H6(A)
PAGE L-1
LABORATORY TEST RESULTS
RESULTS OF MAXIMUM DENSITY AND OPTIMUM MOISTURE
The maximum dry densities and optimum moisture contents of the fill materials as determined by
ASTM D1557-91, Procedure A which uses 25 blows of a 10 pound slide hammer falling from a
height of 18 inches on each of 5 equal layers in a 4 inch diameter 1/30 cubic foot compaction
cylinder and Procedure C which uses 56 blows of a 10 pound slide hammer falling from a height of
18 inches on each of 5 equal layers in a 6 inch diameter 1/13.3 cubic foot compaction cylinder are
presented as follows:
SOIL TYPE/
PROCEDURE
1/A
DESCRIPTION
TAN TO GRAY SILTY
FINE SAND WITH A
TRACE OF CLAY (SM)
MAXIMUM
DRY DENSITY
LB/ CU. FT.
126.5
OPTIMUM
MOISTURE
CONTENT
%DRYWT. LOCATION
9.8 B-1 @2.0'
RESULTS OF PARTICLE SIZE ANALYSIS
U.S. Standard Percent Passing Percent Passing
Sieve Size B-1 @2.0' B-2@2.5'
(ASTM D-422) Undocumented Fill Colluviurn
2" -
l" --
1/2" --
3/8" 100 100
#4 97 99
#8 88 99
#16 67 97
#30 49 94
#40 43 85
#60 31 41
#100 24 26
#200 20 21
I
' uses SM SM
9
SLOWIK PROJECT NO.03-1106H6(A)
PAGE L-2
LABORATORY TEST RESULTS
RESULTS OF EXPANSION INDEX TEST
An expansion test in conformance with ASTM D4829 was performed on a representative sample of
on-site soils to determine volumetric change characteristics with change in moisture content. The
recorded expansion of the sample is presented as follows:
INITIAL
MOISTURE
CONTENT%
9.6
SATURATED
MOISTURE
CONTENT%
18.7
INITIAL DRY
DENSITY
LB.ICU. FT.
108.7
EXPANSION
INDEX
0
LOCATION
B-2@2.0'
SLOWIK PROJECT NO.03-1106H6(A)
REFERENCES
1. "1997 Edition, Uniform Building Code, Volume 2, Structural
Engineering and Design Provisions".
2. "Maps of Known Active Fault Near-Source Zones in California and
Adjacent Portions of Nevada", Page 0-36, used with the 1997
Edition of the Uniform Building Code, Published by International
Conference of Building Officials.
3. "Geologic Maps of the Northwestern Part of San Diego County,
California. Plate No. 1, Geologic Maps of the Oceanside, San Luis
Rey and San Marcos 7.5' Quadrangles", by Siang S. Tan and Michael
P. Kennedy, 1996.
10
EAST COUNTY SOIL CONSULTATION
AND ENGINEERING, INC.
10925 HARTLEY ROAD, SUITE I
SANTEE, CALIFORNIA 92071
(619) 258-7901
APPENDIX A
RECOMMENDED EARTHWORK SPECIFICATIONS
l. General Description
The intent of these specifications is to obtain uniformity and adequate strength in filled ground so
that the proposed structures may be safely supported. The procedures include the clearing and
preparation of the land to be filled, processing the fill soils, the spreading, and compaction of the
filled areas to conform with the lines and grades as shown on the approved plans.
The owner shall retain a Civil Engineer qualified in soil mechanics (herein referred to as engineer)
to inspect and test earthwork in accordance with these specifications. The engineer shall advise the
owner and grading contractor immediately if any unsatisfactory conditions are observed to exist
and shall have the authority to reject the compacted filled ground until such time that corrective
measures are taken, necessary to comply with the specifications. It shall be the sole responsibility
of the grading contractor to achieve the specified degree of compaction.
2. Preparing Areas to be Filled
(a) All brush, vegetation and any biodegradable refuse shall be removed or otherwise
disposed of so as to leave the areas to be filled free of vegetation and debris. Any uncompacted
filled ground or loose compressible natural ground shall be removed unless the report recommends
otherwise. Any buried tanks or other structures shall be removed and the depression backfilled to
the satisfaction of the engineer.
(b) The natural ground which is determined to be satisfactory for the support of the filled
ground shall then be plowed or scarified to a depth of at least 12 inches (12").
( c) After the natural ground has been prepared, it shall then be brought to the proper
moisture content and compacted to not less than 90 percent of maximum dry density in accordance
with ASTM D1557-91.
( d) Where fills are made on slopes greater than 20 percent, horizontal benches shall be cut
into the firm natural ground. The initial bench at the toe of the fill shall be at least 15 feet in width
on firm undisturbed natural ground. The width of all succeeding benches shall be at least 6 feet.
APPENDIX A 2
3. Fill Materials
All material shall be approved by the engineer and shall consist of materials free from vegetable
matter, and other lumps greater than 6 inches in diameter. If, during grading operations, soils are
found which were not encountered and tested in the preliminary investigation, tests on these soils
shall be performed to determine their physical characteristics. Any special treatment recommended
in the preliminary or subsequent soils reports not covered herein shall become an addendum to
these specifications.
4. Placing and Compacting Fill Materials
(a) When the moisture content of the fill material is below that specified, water shall be
added until the moisture content is near optimum to assure uniform mixing and effective
compaction.
(b) When the moisture content of the fill materials is above that specified, the fill material
shall be aerated by blading and scarifying or other satisfactory methods until the moisture content is
near optimum as specified.
( c) After processing, the suitable fill materials shall be placed in layers which, when
compacted, shall ~ot exceed six inches (6"). Each layer shall be spread evenly and shall be
thoroughly mixed during the spreading insure uniformity of materials and moisture in each layer. ·
(d) After each layer has been placed, mixed and spread evenly, it shall be thoroughly
compacted to not less than the density set forth in paragraph 2 (c) above. Compaction shall be
accomplished with approval types of compaction equipment. Rolling shall be accomplished while
the fill material is at the specified moisture content. In place density tests shall be performed in
accordance with ASTM D1556-90.
( e) The surfaces of the fill slopes shall be compacted by means of sheepsfoot rollers or other
suitable equipment. Compacting operations shall be continued until the slopes are stable and until
there is no appreciable amount of loose soil on the slopes.
5. Inspection
Sufficient inspection by our firm or the Soil's Engineer of record and/or his/her representative shall
be maintained during the filling and compacting operations so that he/she can verify that the fill
was constructed in accordance with the accepted specifications.
6. Seasonal Limits
No fill material shall be placed, spread, or rolled if weather conditions increase the moisture
content above permissible limits. When the work is interrupted by rain, fill operations shall not be
resumed until the moisture content and density of fill are as previously specified.
All recommendations presented in the attached report are a part of these specifications.
2