HomeMy WebLinkAboutCDP 13-23; Burchfield Deck Addition; Coastal Development Permit (CDP) (2)UPDATED GEOTECHNICAL INVESTIGATION
AND COASTAL DESIGN CRITERIA
Proposed Patio
2627 Ocean Street
Carlsbad, Califomia
HETHERINGTON ENGINEERING, INC.
HETHERIIMGTOIM ElMGINEERilVIG, IIMC.
SOIL & FOUNDATION ENGINEERING • ENGINEERING GEOLOGY • HYDROGEOLOGY
December 27, 2013
ProjectNo. 7227.1
Log No. 16417
Ms. Nancy Burchfield
2880 North Larkin Avenue
Fresno, Califomia 93727
Subject: UPDATED GEOTECHNICAL INVESTIGATION
AND COASTAL DESIGN CRITERIA
Proposed Patio
2627 Ocean Street
Carlsbad, Califomia
References: Attached
Dear Ms. Burchfield:
In accordance with your request, we have performed an updated geotechnical
investigation and are providing coastal design criteria for a proposed patio at the rear of
the existing single-family residence at the subject site. Our work was performed in
November and December 2013. The purpose of our work was to update the previous
geotechnical work performed by Hetherington Engineering, Inc. (References 2 and 3) and
provide coastal design criteria for the subject property. We have been provided with
architectural plans for the proposed patio (Reference 5). This report includes coastal
design criteria, seismic design criteria in accordance with the 2010 Califomia Building
Code, and grading/foundation recommendations for the proposed construction.
Our scope of work included the following:
• Research and review of available plans and geologic literature pertinent to the site
(see References).
• Research and review of available reports and plans pertinent to coastal processes
along the north San Diego County shoreline.
• Site reconnaissance.
• Engineering and geologic analysis.
• Preparation of this report providing our findings, and our conclusions and
recommendations relative to the proposed patio.
5365 Avenida Encinas, Suite A • Carlsbad, CA 92008-4369 • (760) 931-1917 • Fax (760) 931-0545
327 Third Street • Laguna Beach, CA 92651-2306 • (949) 715-5440 • Fax (949) 715-5442
www.hetheringtonengineering.com
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27, 2013
Page 2
SITE DESCRIPTION
The subject property is located at 2627 Ocean Street, Carlsbad, Califomia and is also
identified as Assessor's Parcel No. 203-140-07-00 (see Location Map, Figure 1). The
site consists of a rectangular-shaped lot situated on a gently sloping beach-bluff that
presently supports a two-story, wood-frame single-family residence with attached garage.
Rock riprap, which we tmderstand was placed in early 1983, is present at the base of the
bluff Overall relief across the property between street grade and the base of the bluff is
approximately 30- feet. The subject site is bordered to the north and south by adjacent
single-family residential lots of approximately the same elevation, to the east by Ocean
Street and to the west by the Pacific Ocean.
PROPOSED DEVELOPMENT
It is our imderstanding that proposed development consists of a new patio with a finished
fioor elevation of approximately 25-feet (msl). The plans indicate that the patio structure
will be raised-wood and masonry. A non-habitable space beneath the deck is proposed.
Building loads are expected to be typical for this type of relatively light constmction.
Grading is anticipated to be minor.
SUBSURFACE EXPLORATION
Subsurface conditions were previously explored by excavating two small-diameter
borings vsdth a tripod-mounted auger drill rig to maximimi depths of approximately 13.5
and 29-feet below site grades and a test pit was hand-excavated to a depth of
approximately 7-feet below site grades. The approximate locations of the borings and
test pit are shown on the attached Plot Plan, Figtore 2.
The subsurface exploration was supervised by a geologist from this office, who visually
classified the soil materials, and obtained bulk and relatively undisturbed samples for
laboratory testing. The soils were visually classified according to the Unified Soil
Classification System. Soil classifications are shown on the attached Boring and Test Pit
Logs, Figures 4 through 6.
LABORATORY TESTING
Laboratory testing was previously performed on samples obtained during the subsurface
exploration. Tests performed consisted of the following:
• Dry Density and Moisture Content (ASTM: D 2216)
HETHERINGTON ENGINEERING, INC.
ADAPTED FROM: The Thomas Guide, San Diego County, 2004 Edition
I
N
I SCALE: 1"-2000'
(1 Grid = 0.5 x 0.5 miles)
LOCATION MAP
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
2627 Ocean Street j
Carlsbad, California HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS PROJECTNO. 7227.1 FIGURE NO. 1
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27,2013
Page 3
• Sulfate Content (EPA 903 8)
• Direct Shear (ASTM: D 3080)
• Expansion (ASTM: D 4829)
• Atterberg Limits (ASTM: D 4318)
• Maximum Dry Density/Optimum Moisture Content (ASTM: D 1557)
Results of the dry density and moisture content determinations are presented on the
Boring Logs and the remaining laboratory test results are presented on the Laboratory
Test Results, Figtires 7 and 8.
SOIL AND GEOLOGIC CONDITIONS
1. Geologic Setting
The subject site is located within the coastal plain region of northwestem San Diego
County, Califomia and is situated within the west central portion of the USGS San
Luis Rey 7-1/2 minute quadrangle. The coastal plain region of San Diego Coimty is
underlain largely by middle and upper Eocene marine and non-marine sedimentary
units of the "San Diego Embayment". These units have been modified by wave-cut
action during Pleistocene sea-level changes. The modification has resulted in marine
abrasion platforms characterized by "stair-step" morphology. Sediments of marine
and non-marine origin mantle the wave-cut terraces and increase in age and elevation
fi"om west to east.
Based on the results of our investigation, the subject site is imderlain by fill.
Pleistocene terrace deposits and sedimentary bedrock ofthe Santiago Formation.
No known or reported deep-seated landsliding is known to exist on the site. No
knovm or reported active or potentially active faults exist within the site.
2. Geologic Units
a. Fill - A relatively thin veneer of fill was encountered in boring B-2. The fill is
comprised of damp, loose, silty fine to medium sand.
HETHERINGTON ENGINEERING, INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27, 2013
Page 4
b. Terrace Deposits - Terrace deposits encountered in the exploratory borings and
test pit consisted generally of damp to wet, dense to very dense, light red brown to
orange brown, silty fine to coarse-grained sand.
c. Bedrock (Santiago Formation) - Bedrock encountered in the exploratory borings
consisted generally of damp, dense to very dense, light olive to yellow green, silty
to clayey fine sandstone.
3. Groimdwater
Groundwater was encountered in boring B-2 at approximately 10-feet below the
groimd surface. It should be noted, however, that fluctuations in the amount and level
of groundwater may occur due to variations in rainfall, irrigation, tidal fluctuation and
other factors that may not have been evident at the time of our field investigation.
SEISMICITY
The site is located within the seismically active southem Califomia region. There are,
however, no known active or potentially active faults presently mapped that pass through
the site. Active fault zones within the general site region include the Rose
Canyon/Newport-Inglewood, Coronado Bank/Palos Verdes Hills, and Elsinore. Strong
ground motion could also be expected fi-om earthquakes occurring along the San Jacinto
and San Andreas fault zones, which lie northeast of the site at greater distances, as well as
a number of other offshore faults.
The following table lists the known active faults that would have the most significant
impact on the site:
Fault
Maximum Probable
Earthquake
(Moment
Magnitude)
Slip Rate
(mm/year)
Fault
Type
Rose Canyon
(6.0-kilometers/3.7-miles SW) 6.9 1.5 B
Coronado Bank/Palos Verdes Hills
(38-kilometers/23.4-miles SW) 7.6 3 B
Elsinore (Julian Segment)
(38-kilometers/23.4-miles NE) 7.3 5 A
HETHERINGTON ENGINEERING, INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERL\
ProjectNo. 7227.1
Log No. 16417
December 27, 2013
Page 5
SEISMIC EFFECTS
1. Ground Accelerations
The most significant probable earthquake to effect the property would be a 6.9
magnitude earthquake on the Rose Canyon fault zone. Based on Section 1803.5.12 of
the 2010 Califomia Building Code, peak ground accelerations of 0.36g are possible
for the design earthquake.
2. Ground Cracks
The risk of fault surface mpture due to active faulting is considered low due to the
absence of an active fault within the site. Ground cracks due to shaking from seismic
events in the region are possible, as with all of southem Califomia.
3. Landsliding
The risk of seismically induced landsliding effecting the site is considered negligible
due to the gently sloping topography of the property.
4. Liquefaction
The risk of liquefaction is considered low due to the dense underlying earth materials.
5. Tsunamis
The "Tsunami Inundation Map..." (Reference 1), indicates that the tsunamis
inundation area extends to about elevation 25-feet (msl) in the site vicinity.
6. Coastal Design Criteria
The following coastal design criteria are based on data taken from the available
referenced oceanographic reports/literature that are considered appropriate for the
subject location (References 6, 7, 8 and 10). Calculations have been performed in
accordance with the guidelines presented in "Coastal Flood Plain Development,
Orange County Coastline..." (Reference 6) and "Shore Protection Manual..."
(Reference 10). We have ignored the presence of the riprap revetment in our coastal
design criteria as required by the city of Carlsbad.
HETHERINGTON ENGINEERING. INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27, 2013
Page 6
The highest observed water level used in the calculations (-1-7.4 ft. NGVD) is from the
La Jolla Station (Reference 8). The anticipated rise in sea level over the next 75-years
(Reference 7), estimated to be 2.0-feet, was then added to the highest observed water
level to obtain the design still water level. We have conservatively used a scour
elevation of 0.0-feet (NGVD) in the analysis. The following is a summary of the
oceanographic parameters used in the wave runup analysis.
Still Water Elevation (Hw) = +7.4-feet (NGVD)
Scour Elevation (Hsc) = 0.0-feet (NGVD)
Water Depth (ds) = +7.4-feet (NGVD)
Design Wave Period for elevation of breaking wave (T) = 22 sec.
Elevation of Breaking Wave (Hb) = +14.8-feet (NGVD)
Run-up Elevation (HR) = +19.4-feet (NGVD) for riprap inclined at 1.5:1 (H:V)
CONCLUSIONS AND RECOMMENDATIONS
1. General
The proposed patio is considered feasible from a geotechnical standpoint. Grading
and foundation plans should consider the appropriate geotechnical features of the site.
Provided that the recommendations presented in this report and good constmction
practices are utilized during the design and constmction, the proposed constmction is
not anticipated to adversely impact the adjacent properties from a geotechnical
standpoint.
Due to coastal design considerations, the proposed patio should be supported by
drilled piers founded in the underlying bedrock and designed for wave forces as well
as stmctural loads. Since the area below the patio is intended to be enclosed non-
habitable space, provisions should be made to withstand uplift pressures and for
venting the pressure from water and trapped air. Consideration can be given to
making the non-habitable space walls breakaway elements as the costs to design the
walls for wave impact forces may be cost prohibitive.
HETHERINGTON ENGINEERING, INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27, 2013
Page 7
2. Seismic Parameters for Stmctural Design
Seismic considerations that may be used for stmctural design at the site include the
following:
a. Ground Motion - The proposed patio should be designed and constmcted to resist
the effects of seismic ground motions as provided in Section 1613 of the 2010
Califomia Building Code.
Site Address: 2627 Ocean Sfreet, Carlsbad, Califomia
Latitude: 33.161°
Longitude:-117.3559°
b. Spectral Response Accelerations - Using the location of the property and data
obtained from the U.S.G.S. Java Ground Motion Calculator Program, short period
Spectral Response Accelerations Ss (0.2 second period) and Si (1.0 second
period) are:
Ss= 1.355
Si = 0.511
c. Site Class - In accordance with Table 1613.5.2, and the underlying geologic
conditions, a Site Class D is considered appropriate for the subject property.
d. Site Coefficients Fg and Fy - In accordance with Table 1613.5.3 and considering
the values of Ss and Si, Site Coefficients for a Class D site are:
Fa =1.0
Fv= 1.5
e. Spectral Response Acceleration Parameters Sm, and Sm^ - In accordance with
Section 1613.5.3 and considering the values of Ss and Si, and Fa and Fv, Spectral
Response Acceleration Parameters for Maximum Considered Earthquake are:
Sms ^ (Fa)(Ss) = (1.00) (1.355) =1.355
Smi (Fv)(Si) = (1.5) (0.511) = 0.766
HETHERINGTON ENGINEERING, INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27,2013
Page 8
f Design Spectral Response Acceleration Parameters Sd, and Sd^ - In accordance
with Section 1613.5.4 and considering the values of Sms and Smi, Design Spectral
Response Acceleration Parameters for Maximum Considered Earthquake are:
Sds = 2/3 Sms = 2/3 (1.355) = 0.903
Sdi = 2/3 Smi = 2/3 (0.766) = 0.511
g. Long Period Transition Period - A Long Period Transition Period of TL = 8
seconds is provided for use in San Diego County.
h. Seismic Design Category - In accordance with Tables 1613.5.6(1) and
1613.5.6(2), and ASCE 7-05, an Occupancy Category II and a Seismic Design
Category D are considered appropriate for the subject property.
3. Site Grading
Prior to any grading, the site should be cleared of any existing debris and vegetation.
Materials generated during clearing should be properly disposed of at an approved
location off-site. Holes resulting from the removal of buried obstmctions that may be
encountered during grading should be removed and replaced with compacted fill.
In areas where any new on-grade improvements are plaimed (including hardscape)
existing fill should be removed and replaced as compacted fill. Removal depths on
the order of approximately 2 to 3-feet below existing site grades are anticipated. The
removals should extend to at least 3-feet beyond the limits of the proposed
improvements where possible. Final removal depths should be determined in the
field during grading by the Geotechnical Consultant. Followdng removals, the
exposed subgrade should be scarified, moisture conditioned to about optimum
moisture content, and compacted to a minimum of 90-percent relative compaction
based upon ASTM: D-1557.
Fill should be compacted by mechanical means in uniform horizontal lifts of 6 to 8-
inches in thickness. All fill should be compacted to a minimum relative compaction
of 90-percent based upon ASTM: D 1557. The on-site materials are suitable for use
as compacted fill provided all vegetation and debris are removed. Rock fragments
over 6-inches in maximum dimension and other perishable or unsuitable materials
should be excluded from the fill. All grading should be observed and tested as
necessary by the Geotechnical Consultant.
HETHERINGTON ENGINEERING, INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27, 2013
Page 9
4. Foundations
Due to the anticipated bluff retreat, the proposed patio should be supported by drilled
piers founded in approved bedrock. The drilled piers should be designed to resist
wave forces as well as the stmctural loads. Constmction difficulties due to caving
sands and the presence of groundwater should be anticipated by the contractor.
Drilled piers should extend at least 5-feet into approved bedrock and should have a
minimum diameter of 24-inches. Drilled piers founded as recommended may be
designed for a dead plus live load end bearing capacity of 4000-pounds-per-square-
foot. This value may be increased by one-third for wind and seismic forces. A skin
friction value of 200-pounds-per-square-foot may be assumed in bedrock. Piers may
resist lateral loads by a passive pressure of 250-pounds-per-square-foot per foot of
depth into bedrock to a maximum value of 4000-pounds-per-square-foot. The passive
resistance may be calculated over two pier diameters.
Total and differential settlement of the proposed new constmction due to foundation
loads is considered to be less than 1/2 and 1/4 inch, respectively, for drilled piers
founded as recommended.
5. Retaining Walls
Retaining wall foundations should be designed in accordance with the previous
building foundation recommendations. Retaining walls free to rotate (cantilevered
walls) should be designed for an active pressure of 35-pounds-per-cubic-foot
(equivalent fluid pressure) assuming level backfill consisting of the granular on-site
soils. Any additional surcharge pressure behind the walls should be added to this
value. Retaining walls should be provided with adequate drainage to prevent buildup
of hydrostatic pressure and should be adequately waterproofed. The subdrain system
behind retaining walls should consist of at least 4-inch diameter Schedule 40 (or
equivalent) perforated (perforations down) PVC pipe embedded in at least 1 cubic
foot of 3/4-inch crushed rock per lineal foot of pipe all wrapped in approved filter
fabric. Recommendations for wall waterproofing should be provided by the project
Architect and/or Stmctural Engineer.
HETHERINGTON ENGINEERING, INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27,2013
Page 10
6. Temporary Slopes
Temporary slopes should be inclined at a slope ratio no steeper that 1:1 (horizontal to
vertical) or shored. Field observations by the Engineering Geologist during grading
of temporary slopes is recommended and considered necessary to confirm anticipated
conditions and to provide revised recommendations if warranted.
7. Concrete Flatwork
Concrete flatwork should be at least 4-inches thick (actual) and reinforced with No. 3
bars spaced at 18-inches on center (two directions) and placed on chairs so that the
remforcement is in the center of the slab. The slab subgrade should be thoroughly
moistened prior to placement of concrete. Contraction joints should be provided at
10-feet spacing (maximum). It should be noted that any flatwork not supported by
the recommended drilled piers will be susceptible to bluff retreat and resulting
damage.
8. Soluble Sulfate
Representative samples of the on-site soils were previously submitted for sulfate
analyses. The results ofthe soluble sulfate tests per EPA 9038 methods are presented
in the attached Appendix A. The sulfate content of the on-site soils is consistent with
a negligible sulfate exposure classification per Table 4.2.1 and 4.3.1 of the American
Concrete Institute publication 318. However, due to the proximity of the proposed
constmction to seawater, concrete should be designed for a severe sulfate exposure.
Other corrosivity testing has not been performed, consequently, the on-site soils
should be assumed to be severely corrosive to buried metals unless testing is
performed to indicate otherwise.
9. Retaining Wall and Trench Backfill
All retaining wall and trench backfill should be compacted to at least 90-percent
relative compaction based upon ASTM: D1557 and the backfill should be observed
and tested by the Geotechnical Consultant.
HETHERINGTON ENGINEERING, INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27, 2013
Page 11
10. Recommended Observation and Testing During Constmction
The following tests and/or observations by the Geotechnical Consultant are
recommended:
a. Observation and testing during grading.
b. Observation of drilled pier excavations prior to placement of forms and
reinforcement.
c. Retaining wall backdrains.
d. Utility french and retaining wall backfill.
11. Grading and Foundation Plan Review
Final grading and foundation plans should be reviewed by the Geotechnical
Consultant to corifirm conformance with the recommendations presented herein or to
modify the recommendations as necessary.
LIMITATIONS
The analyses, conclusions and recommendations contained in this report are based on site
conditions, as they existed at the time of our investigation and further assume the
excavations to be representative of the subsurface conditions throughout the site. If
different subsurface conditions from those encountered during our exploration are
observed or appear to be present in excavations, the Geotechnical Consultant should be
promptly notified for review and reconsideration of recommendations.
Our investigation was performed using the degree of care and skill ordinarily exercised,
under similar circumstances, by reputable Geotechnical Consultants practicing in this or
similar localities. No other warranty, express or implied, is made as to the conclusions
and professional advice included in this report.
HETHERINGTON ENGINEERING, INC.
UPDATED GEOTECHNICAL INVESTIGATION AND COASTAL DESIGN
CRITERIA
ProjectNo. 7227.1
Log No. 16417
December 27, 2013
Page 12
This opportunity to be of service is sincerely appreciated. If you have any questions,
please call this office.
Sincerely,
Hetherington Engineering, Inc.
*aul A
Professional Geologist 3772
Certified Engineering Geolo
Certified Hydrogeologist 59 ll
(expires 3/31/14)
Attachments: Location Map
Plot Plan
Geologic Cross-Section
Boring and Test Pit Logs
Laboratory Test Results
Civil Enginedr 304^
Geotechnical
(expires 3/31/
Figure 1
Figure 2
Figure 3
Figures 4 through 6
Figures 7 and 8
Distribution: 5-Addressee
1-via e-mail (nancv(2),spravforce.com)
HETHERINGTON ENGINEERING, INC.
REFERENCES
1) Califomia Geological Survey, "Tsunami Inundation Map for Planning, Oceanside
Quadrangle, San Luis Rey Quadrangle," dated June 1,2009.
2) Hetherington Engineering, Inc., "Geotechnical Investigation, Proposed Single-
Family Residence, 2627 Ocean Street, Carlsbad, Califomia, APN: 203-140-07-
01," dated November 30, 2005.
3) Hetherington Engineering, Inc., "Response to City of Carlsbad Review Letter,
Amendment to Geotechnical Investigation, Proposed Single-Family Residence,
2627 Ocean Sfreet, Carlsbad, Califomia," dated September 12,2006.
4) ICBO, "Califomia Building Code," 2010 Edition.
5) J. Quan Design, Architectural Plans, "Burchfield Patio, 2625 Ocean Street,
Carlsbad, CA 92008," dated October 9, 2012 (Sheets AO.O, Al.O, Al.l, A2.0,
A2.1, AD.l andAD.2).
6) Moffatt and Nichol, Engineers, , "Coastal Flood Plan Development, Orange
County Coastline," dated January 1985.
7) Moffatt & Nichol, et al., "San Diego Region Coastal, Sea Level Rise Analysis,
Draft Report," dated Febmary 2013.
8) NOAA.gov, Station 9410230 (La Jolla, Califomia), oceanographic data.
9) Peterson, Mark P., et al, "Documentation for the 2008 Update ofthe United States
National Seismic Hazards Maps," USGS Open File Report 2008-1128, dated
2008.
10) US Army Corps of Engineers, "Shore Protection Manual," dated 1984.
11) United States Geologic Survey, "Java Ground Motion Calculator," Version 5.1.0.
12) 2007 Working Group and Califomia Earthquake Probability, "The Uniform
Califomia Earthquake Rupture Forecast, Version 2 (UCERF-2)," USGS Open
File Report 2007-1437 and CGS Special Report 203, dated 2008.
ProjectNo. 7227.1
Log No. 16417
HETHERINGTON ENGINEERING, INC.
LEGEND
A'
10 15 20
APPROXIMATE LOCATION OF BORING
APPROXIMATE LOCATION OF TEST TRENCH
APPROXIMATE LIMITS OF GEOLOGIC CROSS-SECTION PLOT PLAN
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
2627 Ocean Street
Carlsbad, Califomia HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS PROJECT NO. 7227.1 FIGURE NO. 2
PRESUMED BLUFF EDGE AT 75 YEARS (HEI 2006)
EXISTING BLUFF EDGE —,
50 n
40-
30-
SCALE: 1"= 10'
1
r50
-40
-30
-20
-10
10 15 20
GEOLOGIC CROSS-SECTION A - A'
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
2627 Ocean Street
Carlsbad, Califomia HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS PROJECT NO. 7227.1 FIGURE NO. 3
DRILLING COMPANY: Pacific Drilling RIG: Tri-pod DATE: 10/19/05
BORING DIAMETER: 6" DRIVE WEIGHT: 140 Ibs DROP: 30' ELEVATION: 39' +
EH
W
DJ
EH
DJ
W
Q
0.0
EH O O tu \
OT B O
m
>H
EH
H
OT 2 W Q
>H a;
Q
o a
cc; D
EH
OT
M o s
EH 2 M
EH
O U
OT —
OT
<; OT
o u
OT
H
O D
OT ~-
BORING NO. B-1
SOIL DESCRIPTION
5.0-
10.0-
15.0-
20.0-
25.0-
30.0-
35.0-
18
22
23
25
34
35
60
65
55
119
116
111
107
101
103
51 100
102
118
6.9
7.3
6.8
6.0
4.0
98 4.2
4.5
4.2
20.5
13.4
TERRACE DEPOSITS: Dark orange brown silty fine to
medium sand, damp, dense, non porous
@ 7': Becomes light red brown silty fine to medium sand,
damp, dense
10': Becomes medium to coarse grained
@ 13': Light gray brown fine sand, little to no fines, damp,
dense to very dense
@ 16': Color becomes yellowish orange. Sand contains
abundant mica flecks. Damp, friable, dense to very dense
19': Color becomes grey white to orange brown
@ 22': Yellowish brown fine to coarse grained sand, damp,
very dense
@ 25': Gray white to orange brown fine to medium grained
sand with few well rounded gravels to 2 inches in diameter,
moist, dense
@ 26': Gravel zone, well rounded gravels up to 2.5 inches in
diameter in a matrix of coarse grained sand
BEDROCK (Santiago Formation): Light olive to yellow green
silty to clayey fine sandstone, moist, very dense
Total depth 29 feet
No caving
No groundwater or seepage
Boring backfilled with bentonite
BORING LOG
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
2627 Ocean Street
Carlsbad, California HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS PROJECTNO. 5298.1 FIGURE NO. 4
DRILLING COMPANY: Pacific Drilling RIG: Tri-pod DATE: 10/19/05
BORING DIAMETER: 6" DRIVE WEIGHT: 140 Ibs DROP: 30" ELEVATION: 21' +
EH
W
M
faj
ffi
EH
Q
0.0
EH o o
\
OT s o
IJ m
>H
EH
M
OT
z
M Q
>H B: Q
M-l
u
EH
OT
H o s
H 2 W
EH 2 O
u
OT
OT < OT BORING NO. B-2
SOIL DESCRIPTION
5.0-
10.0-
15.0-
20.0-
25.0-
30.0-
35.0-
28
28
32
SM FILL: Medium red brown silty fine to medium sand, damp,
loose, contains brick fragments
106
103
5.2
9.0
101 22.3
TERRACE DEPOSITS: Dark red brown silty medium to coarse
sand, damp, dense, friable
5': Color becomes light red brown to gray white
@ 10': Gray brown fine to medium sand, abundant mica flecks,
moist, dense
@ 12': Gravel zone, well rounded gravels up to 2.5 inches in
diameter in a matrix of coarse grained sand
BEDROCK (Santiago Formation): Light olive to yellow green
silty to clayey fine sandstone, damp, very dense
Total depth 13.5 feet
Groundwater at 10 feet
Caving between 10 and 13.5 feet
Boring backfilled with bentonite
BORING LOG
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
2627 Ocean Street
Carlsbad, California HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS PROJECT NO. 5298.1 FIGURE NO. 5
BACKHOE COMPANY: Mansolf Excavation BUCKET SIZE: Hand Pit DATE: 07/14/06
ffi EH EH Cd
Ol H
Q
0.0 • CQ OT
>H EH
h-l
OT MH ^1 2 O
Ct; w Cb
Q Q —
OT —. OT • a: OT i-q • u o
OT
M O D OT
"SM"
SOIL DESCRIPTION
TEST PIT NO. T-1 ELEVATION: '
5.0—
BEACH SANDS: White to gray, slightly silty fine to medium sand,
dry, loose, friable
Note: Depth to Terrace Deposits varies between 1.9 feet (east)
and 7 feet (west) across the 27-foot-long trench
TERRACE DEPOSITS: Light brown to gray silty fine to medium
sand, moist, dense; massive and moderately oxide stained
10.0—
Maximum depth 7 feet
No groundwater
Severe caving in beach sands
15.0-
LOG OF TEST PITS
HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
2627 Ocean Street
Carlsbad, California HETHERINGTON ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS PROJECTNO. 5298.1 j FIGURE NO. 6
LABORATORY TEST RESULTS
DIRECT SHEAR
(ASTM: D 3080)
Sample Location Angle of Internal
Friction (")
Cohesion
(psf)
Remarks
B-1 @ 10' 29 200 Remolded to 90% @ optimum, consolidated,
saturated, drained
B-1 @ 16' 41 150 Undisturbed, consolidated, saturated, drained
B-l(%28' 32 275 Undisturbed, consolidated, saturated, drained
SULFATE TEST RESULTS
(EPA 9038)
Sample Location Soluble Sulfate in Soil (%)
B-1 (a), 13' -14' 0.0043
B-2 @ 5' - 6' 0.0093
EXPANSION INDEX
(ASTMD: 4829)
Sample Location Initial Compacted Final Expansion Expansion
Moisture Dry Moisture Index Potential
(%) Density
B-1 13' -14' 7.0 114.7 13.5 0 Very low
B-2 (S, 5' - 6' 12.0 101.7 21.2 0 Very low
MAXIMUM DRY DENSITY/OPTIMUM MOISTURE CONTENT
(ASTM: D 1557)
Sample Location Description Maximum Dry Optimum Moisture
Density (pcf) Content (%)
B-1 @0 - 15' Red brown silty fine to medium sand 126.5 9.0
Figure 7
ProjectNo. 7227.1
Log No. 16417
LABORATORY TEST RESULTS
ATTERBERG LIMITS
(ASTM: D 4318)
Sample Location Liquid Limit (%) Plastic Limit (%) Plasticity Index U.S.C.S. Class
(%)
B-1 13'-14' ~ — — NP
B-1 @29'-30' 31 25 6 CL-ML
B-2 (^,5'-6' — ~ NP
Figure 8
ProjectNo. 7227.1
Log No. 16417