HomeMy WebLinkAboutCT 05-13; La Costa Ridge Neighborhood 2.6; La Costa Ridge Project - Geotechnical; 2005-06-02RECORD COPY
PRELIMINARY GEOTECHNICAL
INVESTIGATION
La Costa Ridge Project
Carlsbad, CA
For:
D.R. HORTON/WESTERN PACIFIC HOUSING
June 2, 2005
By:
PACIFIC SOILS ENGINEERING, INC
San Diego, CA
(Work Order 401036)
Initial Date
Om
XO
3o.
Work Order 401036
June 2, 2005
TABLE OF CONTENTS
1.0 INTRODUCTION 3
1.1 Background and Purpose 3
1.2 Scope of Study 3
FIGURE 1
1.3 Project Location and Description 4
1.4 Report Limitations 4
2.0 PROPOSED DEVELOPMENT 5
3.0 FIELD AND LABORATORY STUDIES 5
3.1 Previous Site Studies 5
3.2 Laboratory Testing 5
4.0 GEOLOGIC CONDITIONS 5
4.1 Geologic and Geomorphic Setting 5
4.2 Stratigraphy 6
4.2.1 Topsoil (No Map Symbol) 6
4.2.2 Undocumented Artificial Fill (Map Symbol afu)) 6
4.2.3 Alluvium (Map Symbol Qal) 7
4.2.4 Santiago Formation (Map Symbol Tsa) 7
4.2.5 Granitic Rocks (Map Symbol Kgr) 7
4.3 Geologic Structure 7
4.3.1 Tectonic Framework 7
4.3.2 Regional Faulting 8
4.3.3 Site Geologic Structure 8
4.4 Groundwater 8
4.5 Seismic Hazards 8
4.5.1 Surface Fault Rupture 9
FIGURE 2
TABLE 4.1 9
4.5.2 Seismicity 10
FIGURES 3 and 4
4.5.3 Liquefaction 11
4.5.4 Seismically-Induced Settlement 11
4.5.5 Seismically-Induced Landsliding 11
4.5.6 Seiches and Tsunamis 11
5.0 ENGINEERING ANALYSES 11
5.1 Material Properties 12
5.1.1 Excavation Characteristics 12
5.1.2 Compressibility 12
5.1.3 Expansion Potential 12
5.1.4 Shear Strength Characteristics 12
TABLE 5.1 13
5.1.5 Earthwork Adjustments 13
TABLE 5.2 13
5.1.6 Chemical Analyses 13
TABLE 5.3 14
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5.2 Slope Stability 14
5.3 Bearing Capacity and Lateral Earth Pressures 14
6.0 GEOTECHNICAL CONCLUSIONS AND RECOMMENDATIONS 15
6.1 Site Preparation and Removals 15
6.1.1 Stripping and Deleterious Material Removal 15
6.1.2 Undocumented Fill (Map Symbol afu) 15
6.1.3 Alluvium (Map Symbol Qal) 16
6.1.4 Santiago Formation (Map Symbol Tsa) 16
6.1.5 Granite (Map Symbol Kgr) 16
6.2 Slope Stability and Remediation 16
6.2.1. Cut Slopes 17
6.2.2 Fill Slopes 17
6.2.3 Skin Fill Slopes 18
6.3 Overexcavation of Building Pads 18
6.3.1 Cut/Fill Transition Lots 18
6.3.2 Overexcavation of Street Areas 18
6.4 Subsurface Drainage 19
6.4.1 Canyon Subdrains 19
6.4.2 Heel Drains 19
6.5 Construction Staking, Subdrain and Backdrains Survey 19
6.6 Earthwork Considerations 19
6.6.1 Compaction Standards 19
6.6.2 Documentation of Removals and Drains 19
6.6.3 Treatment of Removal Bottoms 20
6.6.4 Treatment of Saturated Removal Bottoms 20
6.6.5 Fill Placement 20
6.6.6 Benching 20
6.6.7 Mixing 21
6.6.8 Fill Slope Construction 21
6.6.9 Oversized Materials 21
6.6.9.1 Rock Blankets 22
6.6.9.2 Rock Windrows 23
6.6.9.3 Individual Rock Burial 23
6.6.9.4 Rock Disposal Logistics 23
6.6.9.5 Rock Windrows 24
6.7 Haul Roads 24
6.8 Import Materials 24
7.0 DESIGN RECOMMENDATIONS 25
7.1 Structural Design 25
7.1.1 Foundation Design 25
7.1.2 Seismic Design 26
TABLE 7.1 26
7.1.3 Settlement 26
7.1.4 Post-Tensioned Slab/Foundation Design 28
TABLE 7.2 29
7.1.5 Mat Slab Recommendations 29
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Work Order 401036
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7.1.6 Deepened Footings and Structural Setbacks 30
FIGURE 5 31
7.1.7 Backyard Improvements 31
7.2 Retaining Wall Design 31
FIGURE 6 : 32
7.3 Mechanically Stabilized Earth (MSE) Retaining Wall 33
7.4 Other Design and Construction Considerations 33
TABLE 7.3 34
7.4.1 Utility Trench Excavation 34
7.4.2 Utility Trench Backfill 34
7.5 Preliminary Pavement Design 35
TABLE 7.4 35
7.6 Chemical and Corrosion Potential 35
8.0 SLOPE AND LOT MAINTENANCE 36
8.1 Slope Planting 36
8.2 Lot Drainage 36
8.3 Slope Irrigation 37
8.4 Burrowing Animals 37
9.0 FUTURE PLAN REVIEWS 37
10.0 LIMITATIONS 38
APPENDIX A
REFERENCES
APPENDIX B
DESCRIPTION OF SUBSURFACE INVESTIGATION
PLATE A - UNIFIED SOIL CLASSIFICATION SYSTEM
LOGS OF BORINGS AND TEST PITS - B-l THROUGH B-5
TABLE I - LOGS OF TEST PITS TP-1 THROUGH TP-8
APPENDIX C
DESCRIPTION OF LABORATORY ANALYSIS
TABLE II - SUMMARY OF LABORATORY DATA
PLATES C-l AND C-2 - (DIRECT SHEAR PLOTS)
PLATE C-3 - (CONSOLIDATION CURVE)
PLATES C-4 THROUGH C 11 - CHEMICAL TESTING
APPENDIX D
PLATES D-l THROUGH D-5 - SLOPE STABILITY CALCULATIONS
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
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APPENDIX E
EARTHWORK SPECIFICATIONS
PLATES G-l THROUGH G-14 - GRADING DETAILS
APPENDIX F
HOMEOWNERS MAINTENANCE AND IMPROVEMENT CONSIDERATIONS
POCKET ENCLOSURES:
50-SCALE PLAN (PLATE 1)
PACIFIC SOILS ENGINEERING, INC.
raj] PACIFIC SOILS ENGINEERING, INC.
iH[M11 7715 CONVOY COURT, SAN DIEGO, CALIFORNIA 92111
TELEPHONE: (858) 560-1713, FAX: (858) 560-0380
D.R. HORTON INC.
5790 Fleet Street, Suite 210
Carlsbad, CA 92008
February 15, 2007
Work Order 401036
Attention: Mr. Kevin Kasai
Forward Planner
Subject: Updated Preliminary Geotechnical Investigation,
La Costa Ridge Project, in the City of Carlsbad,
California
Reference: Preliminary Geotechnical Investigation, La Costa Ridge
Project (Approximately 7+-Acre Parcel), in the City of
Carlsbad, California, by Pacific Soils Engineering, Inc.,
dated June 2, 2005 (Work Order 401036)
Gentlemen:
Pursuant to your request, presented herein is Pacific Soils Engineering, Inc.'s (PSE) update letter
to the Preliminary Geotechnical Investigation dated June 2, 2005 (Reference) for the La Costa
Ridge project, located in the City of Carlsbad, California.
PSE has reviewed the current 40-scale rough grading plan for La Costa Ridge prepared by David
Evans and Associates (Sheet 3 of 5). Minor changes in pad elevations (+/- 1 foot) and a new
base topography have resulted in a change in the number of cut/fill transition lots present. Plate
1, attached, reflects these changes.
It is PSE's opinion that from a geotechnical perspective, the design changes reflected in the cur-
rent grading plan are minimal. Accordingly, the conditions and recommendations given in the
referenced report remain valid in respect to the proposed grading plan, unless specifically super-
seded herein. All grading should conform to the City of Carlsbad requirements and to the rec-
ommendations presented in the referenced report.
CORPORATE HEADQUARTERS LOS ANGELES COUNTY RIVERSIDE COUNTY SOUTH ORANGE COUNTY
TEL: (714)220-0770 TEL: (310) 325-7272 or (323) 775-6771 TEL: (951) 582-0170 TEL' (714) 730-2122
FAX: (714) 220-9589 FAX: (714) 220-9589 FAX: (951) 582-0176 FAX'(714) 730-5191
Work Order 401036
February 15, 2007
The opportunity to be of service is appreciated. If you have any questions please contact the un-
dersigned.
Respectfully submitted
PACIFIC SOILS ENGINEERING, INC.
JUJi. HUGHES, Eil)
Civil-Engineering Associate
*Y, GE231
j&dtechnical Services
JOHlsrA. HANSON, CEG 990
Vice-President
Dist: (4) Addressee
(4) David Evans and Associates, Attn: Mr. Gabriel Rodriguez
JEH/JAC/JAH:bm:401036, February 15, 2007
PACIFIC SOILS ENGINEERING, INC.
afu
Qal
Tsa
Kgr
-5®
LEGEND
ARTIFICIAL FILL, UNDOCUMENTED
ALLUVIUM
*
SANTIAGO FORMATION
GRANITIC ROCK
APPROXIMATE LOCATION OF GEOLOGIC CONTACT
(DOTTED WHERE BURIED)
APPROXIMATE TARGET ELEVATIONS FOR REMOVALS
APPROXIMATE LOCATION OF TEST PITS (PSE)
APPROXIMATE LOCATION OF HOLLOW STEM BORINGS
(PSE)
CUT/FILL TRANSITION LOT
ANTICIPATED SUBDRAIN LOCATION
PLATE 1
{PACIFIC SOILS ENGINEERING, INC.
7715 CONVOY COURT, SAN DIEGO, CA 92111
| TELEPHONE: (858) 560-1713, FAX: (858) 560-0380
W.O. 401036 DATE: 2-15-07
PATH. Si\etrafttng\401036\of S-07Vlate l.chrg
DAVID EVANS
(ASSOPIATES INC.
Avenue. Suite 300
California 91764
: 909481.5750
909.481.5757
CI!Y APPROVAL
3
blNGINKKR OK WORK
2AGRICL RODRIGUEZ DA:E
RCF NO 599^-8 FXP. 09-30-08
INSCRIPTION. K-302 A STD. DISK STAMPED K 302 1335)SEi IN THE. TO- OF A CONCRETE POS!
LOCATION; LIES 65' EASTERLY OF EASTERN GERM LINE
ON RANCHC SANTA FE ROAD, 133' NORTHERLY
OF ELECTRIC TRANSMISSION LINE POLE MARKED
"riv30!l" AND "TL138?5"
RECORDED:
ELEVATION- 53339 DAKjM: NGVD 1929
CITY OF CARLSBAD i
GRADING AND EROSION CONTROL PLANS FOR:
LA COSTA RIDGE
NEIGHBORHOOD 2.6
APPROVED BY
CONRAD JjAMM ANN PE^.35 06 9 EX 06/03 D ATE
DWN BY: .
CHKD BY:PROJLC" NG.
CT05-13 448-3A
figj! PACIFIC SOILS ENGINEERING, INC.
™ 7715 CONVOY COURT, SAN DIEGO, CALIFORNIA 92111
TELEPHONE: (858) 560-1713, FAX: (858) 560-0380
D.R. HORTON/WESTERN PACIFIC HOUSING
5790 Fleet Street, Suite 210
Carlsbad, California 92008
June 2, 2005
Work Order 401036
Attention: Mr. Dave Dieterle,
Project Manager
Subject: Preliminary Geotechnical Investigation, La Costa Ridge
Project (Approximately 7+-Acre Parcel), in the City of
Carlsbad, California.
References: See Appendix A
Gentlemen:
Pursuant to your request, presented herein is Pacific Soils Engineering, Inc.'s (PSE) preliminary
geotechnical investigation for the La Costa Ridge project, located southwest of Rancho Santa Fe
Road and Melrose Drive, in the City of Carlsbad, California. The major geotechnical issues
identified within this document include:
^ Unsuitable soil removals.
> Excavation characteristics of bedrock.
> Recommendations for pad undercuts.
> Soil chemical analyses.
^ Grading recommendations.
> Design of foundations in anticipation of as-graded soil characteristics.
CORPORATE HEADQUARTERS LOS ANGELES COUNTY RIVERSIDE COUNTY SOUTH ORANGE COUNTY
TEL: (714)220-0770 TEL: (310) 325-7272 or (323) 775-6771 TEL: (951) 582-0170 TEL: (714) 730-2122
FAX: (714)220-9589 FAX: (714) 220-9589 FAX: (951) 582-0176 FAX: (714) 730-5191
Work Order 40103 6
June 2, 2005
Page 2
PSE appreciates the opportunity to provide our services on this project. If you require additional
information, please do not hesitate to contact this office.
Respectfully submitted,
PACIFIC SOILS ENGINEERING, INC. Reviewed by
By_
DOUGLAS M. AYERS,
Engineering Geology Associate
By_
). HAVEN,
Engineering Geology Associate
Reviewed by:
JOHN AJHANSON, CEG 990
Dist: (3) Addressee
(3) D.R. Horton/Western Pacific Housing, Arm: Ms. Tara Taylor
DMA/JAC/SDH/JAH:bm:401036, June 2,2005
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 3
June 1, 2005
1.0 INTRODUCTION
1.1 Background and Purpose
The purpose of this report is to provide geotechnical recommendations for the design
and construction of the project as presented on the enclosed 50-scale preliminary
plan (Plate 1) prepared by Hunsaker and Associates (undated). The pertinent
subsurface information and laboratory data from this study are included in this
report.
1.2 Scope of Study
This study is aimed at providing geotechnical conclusions and recommendations for
the development of the property with regard to: 1) unsuitable soils removals;
2) engineering and excavation characteristics of the earth materials; 3) subsurface
drainage; 4) grading recommendations; and 5) preliminary foundation design
recommendations.
The scope of this study included the following tasks:
> Review of maps and literature (Appendix A).
> Site geologic mapping.
> Excavating, logging and sampling of eight (8) backhoe test pits (Table I in
Appendix B).
> Excavating, logging and sampling of five (5) hollow-stem auger borings,
HS-1 through HS-5 (Plates B-l through B-5).
> Plotting of pertinent geologic data from the current and previous
investigations on the current preliminary design plan (Plate 1).
> Conducting stability analysis of fill slopes, (Plates D-l through D-5 in
Appendix D).
> Analyzing the plans in view of geotechnical conditions and proposed
development.
> Preparing this report and exhibits.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 4
June 2, 2005
1.3 Project Location and Description
The site consisted of approximately seven (7) acres that are situated west of Rancho
Santa Fe Road, east of Corintia Street and south of Melrose Drive, in the City of
Carlsbad, California (Figure 1). The western perimeter is bounded by existing
single-family developments and the southern perimeter is bounded by open space.
Access to the site is via Corintia Street. The site is covered with native grasses with
scattered bushes on the southern portion of the site. Existing uncompacted fills
cover the majority of the site. These undocumented fills were placed in two (2)
phases, with the latest phase consisting of a large pile of construction debris
generated during the ongoing improvements to Rancho Santa Fe Road.
Topographically, the majority of the site consists of a relatively flat sheet-graded pad
draining to the east, bisected by a narrow drainage channel, draining from west to
east. An existing 2 : 1 slope extends downward from the sheet-graded pad into the
existing drainage along the eastern boundary of the project. Although not reflected
on the topography of the plan, a large stockpile of construction debris approximately
twenty-five (25) to thirty (30) feet high is present along the eastern boundary.
1.4 Report Limitations
The conclusions and recommendations in this report are based on the data developed
during our site investigation, review of maps and literature, laboratory data and the
enclosed 50-scale plan.
The materials immediately adjacent to or beneath those observed in the exploratory
excavations may have different characteristics and no representations are made as to
the quality or extent of materials not observed. The recommendations presented
herein are specific to the development plans reflected on the current grading plan.
Modifications to that design or development plans could necessitate revisions to
these recommendations.
PACIFIC SOILS ENGINEERING, INC.
SITE LOCATION MAP
SCALE: 1" = 2000'
SOURCE: RANCHO SANTA FE
7.5" SERIES QUADRANGLE
NATIONAL GEOGRAPHIC
TOPO! 2&03 FIGURE 1
PACIFIC SOILS ENGINEERING, INC.
7715 CONVOY COURT
SAN DIEGO, CALIFORNIA 92111
P: (858) 560-1713 \_ ^ .
W.O.: 401036 DATE: 6/2/05
Work Order 401036 Page 5
June 2, 2005
2.0 PROPOSED DEVELOPMENT
The current site plan calls for the construction of fifty-four (54) building pads for single-
family residential structures along with one (1) recreation pad with associated streets and
utilities. Design cuts up to five (5) feet are shown in the western portion of the site on Lot 1
and fills up to fifteen (15) feet are shown on Lot 12. Cut slopes are designed at slope ratios
of 2 : 1 (horizontal to vertical) or flatter. The highest proposed cut slope is six (6) feet on
Lot 39. Fill slopes are designed at slope ratios of 2 : 1 (horizontal to vertical) or flatter. The
highest proposed fill slope is approximately twenty (20) feet. Various retaining walls are
proposed. Some are anticipated to be conventional retaining walls in addition to plantable
(MSB) retaining walls of up to six (6) feet along the eastern property line,
3.0 FIELD AND LABORATORY STUDIES
3.1 Previous Site Studies
Pacific Soils Engineering, Inc. performed a geotechnical due diligence that included
subsurface exploration with a rubber-tire backhoe and a hollow-stem auger drill rig
(PSE, 2005). The logs of the test pits are presented in Appendix B with the logs of
the borings presented on Plates B-l through B-5, Appendix B.
3.2 Laboratory Testing
Laboratory testing was conducted as part of this geotechnical investigation onsite.
Testing consisted of hydrometer analysis, maximum density, shear strength,
expansion testing and chemical/resistivity. Test results are presented in Appendix C.
Our review of the subsurface investigation and laboratory testing indicates that the
onsite soils are predominately fine- to coarse-grained silty sands that will likely
exhibit "low" to "medium" expansion potential. Limited chemical testing was
conducted on soil samples collected from the site. Test results show that the soluble
sulfate potential for the majority of the onsite soils can be classified as "negligible".
4.0 GEOLOGIC CONDITIONS
4.1 Geologic and Geomorphic Setting
The La Costa Ridge project is located in the Peninsular Ranges geomorphic province
that characterizes the southwest portion of southern California. The Peninsular
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Ranges province is composed of plutonic and metamorphic rock, lesser amounts of
Tertiary volcanic and sedimentary rock and minor veneers and drainage infills of
Quaternary sediment.
The subject site is located in the foothills that border the eastern edge of a relatively
narrow coastal plain that abuts the dominant mountainous terrain to the east. The
coastal plain is composed of relatively flat-lying Pleistocene-, Eocene- and upper
Cretaceous-age sedimentary units. The mountainous terrain is composed of Jurassic
Santiago Peak metavolcanics and Cretaceous granitics that are composed of
granodiorites and tonalites.
4.2 Stratigraphy
The site is underlain at depth by granitic bedrock (Kgr) that in turn is overlain by
sandstones/siltstones of Santiago Formation (Tsa). Overlying the bedrock units are
alluvium and recently placed deposits of undocumented fill. A large pile of
construction debris is located along the east project boundary. Presented below is a
brief description of the geologic units mapped onsite. The distribution of these
geologic units is shown on Plate 1
4.2.1 Topsoil (No Map Symbol)
Topsoils onsite consist of reddish brown clayey sands that are moist and stiff.
The topsoil is rooted and contains common gravels and cobbles. Topsoils
range from one (1) to two (2) feet thick.
4.2.2 Undocumented Artificial Fill (Map Symbol afu))
Undocumented artificial fill was placed in two (2) phases across the site.
The first phase of undocumented fill is found in the western portion of the
site and varies from fine- to coarse-grained tan to gray silty sands to sandy
clays that are slightly moist to moist and loose to moderately firm. This
undocumented fill ranges from approximately one and one-half (1.5) feet at
the southwest corner of the project to twelve (12) feet thick in the central
portion of the site.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 7
June 2, 2005
The second phase of undocumented fill is located in the eastern portion of the
site and consists of a construction debris pile generated during the ongoing
improvements to Rancho Santa Fe Road. This stockpile consists of soil,
asphaltic concrete, concrete and rock particles up to three (3) feet in size. At
this time, it is PSE's understanding that this material will be hauled off as
part of the construction of Rancho Santa Fe Road.
4.2.3 Alluvium (Map Symbol Qal)
Alluvium underlies portions of the undocumented artificial fill (Plate 1). The
alluvium consists of sandy clays and clayey sands that are brown to dark
brown, slightly moist to moist and firm to stiff.
4.2.4 Santiago Formation (Map Symbol Tsa)
Bedrock of the Santiago Formation is exposed in the southern portion of the
site and underlies the undocumented fill across much of the site. The
Santiago Formation (onsite) consists of light brown to olive gray siltstone
and sandstone with orange oxidation and white calcium carbonate deposits
throughout. The unit is slightly moist to moist and moderately hard. The
upper one (1) to three (3) feet of the unit is highly weathered.
4.2.5 Granitic Rocks (Map Symbol Kgr)
Granitic bedrock underlies the Santiago Formation along the southern
boundary. The granitic bedrock is moderately weathered and varies in color
from orange to olive gray. Granitic bedrock consists of medium to coarse
crystalline rock that is slightly moist to moist, moderately hard to very hard.
4.3 Geologic Structure
4.3.1 Tectonic Framework
Structurally, the La Costa Ridge project is located in the Santa Ana sub-block
of the Peninsular Ranges block of Structural Province I, which extends south
into Baja California and terminates on the north against the Transverse
Ranges sub-block of Structural Province II (Jennings, 1985). The Santa Ana
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 8
June 2, 2005
sub-block is bound by the Elsinore Fault Zone on the east and by the
Newport-Inglewood/Rose Canyon Fault Zone on the west.
4.3.2 Regional Faulting
Regional faults in southern California are characterized as having a strong
northwest orientation, which all display right lateral slips, usually with a
vertical component, (Jennings, 1985). Significant faults of this system
displaying Holocene offset are the San Andreas, Elsinore, San Jacinto,
Coronado Bank, Newport-Inglewood and Rose Canyon. Of these, the Rose
Canyon Fault is the closest, at approximately 8.0 miles (12.9 km).
4.3.3 Site Geologic Structure
The onsite geologic structure is based upon our review of literature, maps
and our geologic mapping and subsurface investigation. Randomly oriented
high-angle jointing was observed in the granitic rock outcrop. Faulting was
not observed onsite nor has any faulting been mapped onsite in the reviewed
maps and reports (Appendix A).
4.4 Groundwater
Groundwater was encountered in HS-2 at a depth of fourteen and one-half (14.5)
feet and HS-4 at a depth of twenty (20) feet. Seepage was observed in HS-5 at a
depth of nineteen (19) feet. Groundwater is expected to range from approximately
fourteen (14) feet to twenty (20) feet below proposed grades. In areas of complete
alluvium removals, dewatering and/or specialized grading techniques (top loading,
swamp cats, etc.) may be required to efficiently excavate saturated alluvium.
4.5 Seismic Hazards
Because La Costa Ridge is located in tectonically active southern California, it will
likely experience some effects from future earthquakes. The type or severity of
seismic hazards affecting the site is chiefly dependent upon the distance to the
causative fault, the intensity of the seismic event and the onsite soil characteristics.
The seismic hazard may be primary, such as surface rupture and/or ground shaking,
or secondary, such as liquefaction or landsliding. The following is a site-specific
discussion about ground motion parameters, earthquake-induced landslide hazards
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Page 9
and liquefaction. The purpose of this analysis is to identify potential seismic hazards
and propose mitigations, if necessary, to an acceptable level of risk. The following
seismic hazards discussion is guided by the UBC (1997), CBC (2001), CDMG
(1997) and Petersen and others (1996).
4.5.1 Surface Fault Rupture
Active faulting is not known to exist onsite. The nearest known active fault
is the Rose Canyon Fault, a "Type B" fault (UBC, 1997), located
approximately 8.0 miles (12.9 km) northeast. This conclusion is based on
literature review (references) and PSE's site mapping and sub-surface
investigation. Accordingly, the potential for fault surface rupture on the
subject site is very unlikely.
A listing of active faults within a 100-kilometer (62.5 miles) radius is
presented in Table 4.1.
"" "• , - , *" a •> ""_ ^v^*^ \^«, .» V- V"* t-v r-.? ? ^ V*" * •*"? *r ^;'>^-r:_; i^t-i^-V -''VtRwr^-T'A^rs^• T- - •' "•-*:<**,.'•??• ', -^-v-lfAJCttjjE^*!,.! ,*«4rf^
- jyr-Y^ fv^"^-^^;^IfefiB^^3B^&TO^cftre JfiuQ&t
FAULT NAME
Rose Canyon
Newport-Inglewood (Offshore)
Elsinore-Julian
Elsinore-Temecula
Coronado Bank
Earthquake Valley
Elsinore-Glen Ivy
Palos Verdes
San Jacinto-Anza
San Jacinto-San Jacinto Valley
San Jacinto-Coyote Creek
Elsinore-Coyote Mountain
Chino-Central Ave. (Elsuiore)
Newport-Inglewood (L.A. Basin)
Whittier
San Jacinto-Borrego
DISTANCE
(mi)
8.0
12.2
22.4
22.5
23.1
37.8
37.8
42.9
45.2
47.3
48.2
51.0
52.7
53.1
56.9
60.1
(km)
12.9
19.6
36.1
36.2
37.2
60.8
60.8
69.1
72.8
76.2
77.6
82.1
84.8
85.5
91.5
96.8
v v &• *" %^*?%,"^ **!* * *" *"" '•<**
MAXIMIMMOMENT
MAGNITUDE (Mmax)*
6.9
6.9
7.1
6.8
7.4
6.5
6.8
7.1
7.2
6.9
6.8
6.8
6.7
6.9
6.8
6.6
' Petersen and others (1996) and Blake (EQFAULT, ver. 2.20)
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 10
June 2, 2005
4.5.2 Seismicity
Although no known active faults exist within the project limits, it is likely
that the site will experience ground motion and effects from earthquakes
generated along active faults located offsite. Figure 2 presents a map
showing the active faults in southern California, historical earthquakes (1800
to 1999) and the project site location.
To estimate the potential ground shaking, PSE has performed the
probabilistic seismic hazard analysis (PSHA) outlined in Petersen and others
(1996) and UBC (1997). To perform this analysis, PSE has utilized
FRISKSP, developed from United States Geologic Survey software (FRISK)
by Blake (1989-2000a,b,c).
The attenuation relationships by Boore and others (1997) for material type Sc
(soft rock - shear wave velocity 520 m/s) and material type SD (artificial fill
- shear wave velocity 250 m/s) were utilized. For a complete discussion of
the software and probabilistic methods, the reader is referred to Blake (1989
- 2000a, b, c).
With one standard deviation, FRISKSP computed 0.24g for material type Sc
(Figure 3), and 0.3 Ig for material type SD (Figure 4) as the peak ground
accelerations from the design basis earthquake, the horizontal acceleration
that hypothetically has a ten (10) percent chance of being exceeded in fifty
(50) years.
In sum, these results are based on many unavoidable geological and
statistical uncertainties, but yet are consistent with current standard-of-
practice. As engineering seismology evolves and as more fault-specific
geological data are gathered, more certainty and different methodologies may
also evolve.
PACIFIC SOILS ENGINEERING, INC.
EARTHQUAKE EPICENTER MAP
1100 LA COSTA
LEGEND
x M = 4
-100
-400 -300 -200 -100 0 100 200 300 400 500 600
FIGURE 2
PROBABILITY OF EXCEEDANCE
BOORE ET AL(1997) NEHRP C (520)1
100 SOyrs
0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Acceleration (g)
FIGURE 3
PROBABILITY OF EXCEEDANCE
BOORE ET AL(1997) NEHRP D (250)1
100
90
SOyrs
0
0.0 0.1 0.2 0.3 0.4 0.5 0.6
Acceleration (g)
0.7 0.8 0.9
FIGURE 4
Work Order 401036 Page 11
June 2, 2005
4.5.3 Liquefaction
Seismic agitation of relatively loose saturated sands and silty sands can result
in a buildup of pore pressure. If the pore pressure exceeds the overburden
stresses, a temporary quick condition known as liquefaction may occur. The
effects of liquefaction at a site can manifest in several ways, and may
include: 1) ground oscillations; 2) loss of bearing; 3) lateral spread;
4) dynamic settlement; and 5) flow failure.
The potential for the occurrence of liquefaction at the subject site is
considered extremely low, due to the proposed remedial grading and the
relatively high in-place density of the underlying bedrock.
4.5.4 Seismicallv-Induced Settlement
Upon the completion of the grading recommendations presented in this
report, seismically induced dynamic settlement potential will be reduced to
an "acceptable level of risk" as defined by the State of California.
4.5.5 Seismicallv-Induced Landsliding
Upon completion of remedial grading, a potential for seismically induced
landsliding is considered to be "low" at the La Costa Ridge site.
4.5.6 Seiches and Tsunamis
Seismically induced hazards such as seiches, tsunamis and earthquake-
induced flooding are not considered significant hazards to the La Costa
Ridge project.
5.0 ENGINEERING ANALYSES
Presented herein is a general discussion of the geotechnical properties of the various soil
types and earth materials summarized from our site-specific analyses of the project and the
referenced reports.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 12
June 2, 2005
5.1 Material Properties
5.1.1 Excavation Characteristics
It is anticipated that excavations within the majority of the undocumented
artificial fill, topsoil, alluvium, Santiago and the weathered portions of the
granitic bedrock can be accomplished with conventional equipment. It is
likely that within the granitic rock, oversized granitic "float" will be
encountered within the lower portions of the Santiago Formation and in
weathered granite and may require special handling. It is anticipated that
this condition will be limited to the deeper utility excavations along the
southern boundary of the project.
5.1.2 Compressibility
Onsite materials that are significantly compressible include undocumented
fill, topsoil, alluvium and highly weathered bedrock. Where possible, these
materials will require complete removal prior to placement of fill, where
exposed at design grade and possibly where exposed in cut slopes.
Recommended removal depths are presented in Section 6.1, and earthwork
adjustment shrinkage estimates are presented in Section 5.1.5. In areas
where complete removals of alluvium are not possible due to adjacent
improvements and/or grading restrictions, settlement monitoring may be
required.
5.1.3 Expansion Potential
Based upon the previous testing and PSE's observations, it is anticipated that
the expansion potential of the onsite materials will range from "very low" to
"high".
5.1.4 Shear Strength Characteristics
The following table presents averaged shear strength parameters.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Page 13
; - - ^^SSc^^l&&^:^B vN*. ,^.;^:V ^:- ',•'
"~ '. •"• y-'^y'i^:*- StearStre^hCharacteristteisr,,":'"v.-> .J?r->A-^. --:-'-:*-. - .
Material Description
Compacted Fill
Santiago Formation (Tsa)
Granitic Rock (Kgr)
Cohesion,
C
(ksf)
150
200
300
Friction
Angle
*(Degrees)
29
30
37
Unit
Weight
y(pcf)
130
130
150
5.1.5 Earthwork Adjustments
The following average earthwork adjustment factors have been formulated
for this report.
, r_ - ^ ~:^$jj- *» VT'- y .iv^tyTABLE 5.2 . -^ ^i-^t*^^^*;^^^"^ -„ •
, - * >V: " " 5 zljFv- ^'*V ^ »"3EarthwwJS Adjustments • ; "??V^?J^ 1 *,. Vv%?C,?-,-"
Geologic Unit
Topsoil/Alluvium
Undocumented Artificial Fill
Santiago Formation
Granite - rippable
Granite - blasting
Adjustment Factor
8 -14% shrink
2 - 5% shrink
0 - 3% bulk
10 -15% bulk
15 -20% bulk
These values may be used in an effort to balance the earthwork quantities.
As is the case with every project, contingencies should be made to adjust the
earthwork balance when grading is in progress and actual conditions are
better defined.
5.1.6 Chemical Analyses
The results of chemical/resistivity tests presented on Plates C-4 through C-10
and below in Table 5.3. The tests indicate that the soluble sulfate
concentrations are below 0.1 percent. Accordingly, soluble sulfate potential
for the majority of site soils can be classified as "negligible" in accordance
with Table 19-A-4 of the UBC. Resistivity testing (Plate C-5) resulted in
moderate to high resistivity, indicating a low potential for corrosive attack on
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 14
June 2, 2005
buried metallic construction materials. However, we recommend that a
corrosion engineer be consulted for additional testing and design/
construction recommendations. Testing for sulfates, resistivity and chlorides
should be conducted on the near-surface soils after grading completion.
^"*- ~^~* ,v <* **• ^ *_ ^. ^*_ ~>jv4psU TPE)C~1ltt;Ti1^-?'-C ^ -** " iK'.'i.*". "^ -^^" ^^ ^^.'^'v " «£ ^ ~, -ssat ^c~ JL AJjkJLdEe"" •9*^7 ^,'-r«'^.- "!|£>--'^ ^~^*,
-1 >r^(.~'VtV>»^ [ *.«,-.» ^^-«- 'T-4 «ift - »
Sample
TP-1 @ 8 feet
. HS-2@5feet
,*>,.-*.'->*
Soluble Sulfate Concentrations
0.0060
0.0048
5.2 Slope Stability
Slope stability analyses were performed using the simplified Janbu method for the
case of C and § both > 0, for circular failure surfaces. These stability calculations
were compiled using STEDwin in conjunction with GSTABL7V2 computer code. As
part of our analyses, pseudostatic factor of safeties were determined for rotational
failures using the Janbu method. Slope stability analyses have been conducted on
cut and fill slopes. Once remedial grading is complete, no cut slopes will be present
onsite. Analysis for the highest fill slope (approximately 25 feet) is presented on
Plates D-l and D-2. Also included herein are stability analyses for a twenty- (20)
foot high 2 : 1 fill slope with a six- (6) foot mechanically stabilized earth (MSE)
retaining wall at the toe (Plates D-3 and D-4). Additionally, a surficial stability
analysis for fill and cut slopes is presented on Plate D-5.
5.3 Bearing Capacity and Lateral Earth Pressures
Ultimate bearing capacity values were obtained using the graphs and formula
presented in NA VFA C DM- 7.1. Allowable bearing was determined by applying a
factor of safety of at least three (3) to the ultimate bearing capacity.
Static lateral earth pressures were calculated using Rankine methods for active and
passive cases. If it is desired to use Coulomb forces, a separate analysis specific to
the application can be conducted.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 15
June 2, 2005
6.0 GEOTECHNICAL CONCLUSIONS AND RECOMMENDATIONS
Development of the subject property as proposed is considered feasible, from a geotechnical
standpoint, provided that the conclusions and recommendations presented herein are
incorporated into the design and construction of the project. Presented below are specific
issues identified by this study as possibly impacting site development. Recommendations to
mitigate these issues are presented in the text of this report, with graphic presentation of the
recommendations on the enclosed plans where appropriate.
6.1 Site Preparation and Removals
Grading should be accomplished under the observation and testing of the project
soils engineer and engineering geologist or their authorized representative in
accordance with the recommendations contained herein, the current grading
ordinance of the City of Carlsbad and PSE's Earthwork Specifications (Appendix
E). Undocumented fill, partially saturated (S < 85%), alluvium and weathered
bedrock should be removed in areas planned to receive fill or where exposed at final
grade. The resulting undercuts should be replaced with engineered fill. The extent
of removals can best be determined in the field during grading when observation and
evaluation can be performed by the soil engineer and/or engineering geologist.
Removals should expose competent bedrock and be observed and mapped by the
engineering geologist prior to fill placement, hi general, soils removed during
remedial grading will be suitable for reuse in compacted fills provided they are
properly moisture conditioned and do not contain deleterious materials.
6.1.1 Stripping and Deleterious Material Removal
Existing vegetation, trash, debris and other deleterious materials should be
removed and wasted from the site prior to removal of unsuitable soils and
placement of compacted fill.
6.1.2 Undocumented Fill (Map Symbol afu)
Undocumented fill will require complete removal and recompaction within
the development footprint and where its presence could impact proposed
development or improvements. Other unmapped deposits may exist and will
require removal and recompaction. Excavations into the undocumented fill
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June 2, 2005
could encounter construction debris. Inert debris (brick, concrete, asphaltic
concrete, etc.) can be re-used as compacted fill. Asphaltic concrete debris
should be placed in the upper five (5) feet of roadway fills and should be less
than eight (8) inches in maximum dimension.
6.1.3 Alluvium (Map Symbol Qal)
Alluvium found within the re-entrant drainage and adjacent to Rancho Santa
Fe Road should be completely removed prior to the placement of compacted
fill where possible. Within Lots 10 through 23, partial removals of saturated
alluvium can be conducted due to limitations caused by property line
restrictions and existing improvements. Final determination as to the depth
and lateral extent of alluvium removals should be determined in the field.
Alluvium removal depths are expected to range from three (3) to twenty-two
(22) feet.
6.1.4 Santiago Formation (Map Symbol Tsa)
Weathered portions of this unit should be removed prior to fill placement and
where exposed in cuts. Removal depths of one (1) to three (3) feet are
anticipated to expose competent material.
6.1.5 Granite (Map Symbol Kgr)
Weathered portions of this unit should be removed prior to fill placement and
where exposed in cuts. Removal depths of one (1) to three (3) feet are
anticipated to expose competent material.
6.2 Slope Stability and Remediation
Close geologic inspection should be conducted during grading to observe if soil and
geologic conditions differ significantly from those anticipated. Should field
conditions dictate, modifications to the recommendations presented herein may be
necessary and should be based upon conditions exposed in the field at the time of
grading.
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June 2, 2005
6.2.1 Cut Slopes
Proposed cut slopes have been designed at slope ratios of 2 : 1 (horizontal to
vertical). It is anticipated that cut slopes will be in undocumented fill and
will be removed and replaced with compacted fill during the remedial
grading operations. Accordingly, at the conclusion of grading no cut slopes
will be present onsite.
6.2.2 Fill Slopes
Fill slopes are designed at ratios of 2 : 1 (horizontal to vertical) or flatter.
The highest design fill slope is approximately twenty (20) feet. In addition,
fifteen- (15) foot high fill slopes with MSB walls up to six (6) feet at the toe
of the slope are proposed. Fill slopes, when properly constructed with onsite
materials, are expected to be grossly stable as designed. Stability
calculations are presented on Plates D-l through D-5 and in Appendix D.
Fill slopes constructed at 2 : 1 ratios or flatter can be expected to perform
satisfactorily when properly constructed with onsite materials and maintained
as described in Appendix F. Marginal surficial stability may exist if slopes
are not properly maintained or are subjected to inappropriate irrigation
practices. Slope protection and appropriate landscaping will improve
surficial stability and should be considered.
Keyways should be constructed at the toe of all fill slopes toeing on existing
or cut grade. Fill keys should have a minimum width equal to fifteen (15)
feet or one-half (1/2) the height of ascending slope, whichever is greater.
Where possible, unsuitable soil removals below the toe of proposed fill
slopes should extend outward from the catch point of the design toe at a
minimum 1 : 1 projection to an approved cleanout as shown on Plate G-5
(Appendix E). Backcuts should be cut no steeper than 1 : 1 or as
recommended by the geotechnical engineer.
PACIFIC SOILS ENGINEERING, INC.
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June 2, 2005
6.2.3 Skin Fill Slopes
Although unlikely given the recommended remedial grading, skin fills or thin
fill sections against natural slopes should be avoided. If other skin fill
conditions are identified in the field or are created by remedial grading, it is
recommended that a backcut and keyway be established such that a minimum
fill thickness equal to one-half (1/2) the remaining slope height [not less than
fifteen (15) feet] is provided for all skin fill conditions. This criterion should
be implemented for the entire slope height. Drains may be required at the
heel of skin fills and would be designed based upon exposed conditions.
6.3 Overexcavation of Building Pads
6.3.1 Cut/Fill Transition Lots
Where design grades and/or remedial grading activities create a cut/fill
transition, the cut and shallow fill portions of the building pad should be
overexcavated a minimum depth of three (3) feet and replaced to design
grade with compacted fill. Lots anticipated to require replacement fills due
to cut/fill transitions are indicated with a (C) on the enclosed plans. All
undercuts should be graded such that a gradient of at least one (1) percent is
maintained toward deeper fill areas or the front of the pad. The entire pad
area of these lots should be undercut. Replacement fills should be compacted
to project specifications as discussed in Section 6.7.1.
6.3.2 Overexcavation of Street Areas
Although unlikely, it is recommended that the street areas with design cut or
shallow fill located in the granitic bedrock be overexcavated a minimum of one
(1) foot below the deepest utility and replaced with compacted fill. This will
facilitate the use of conventional trenching equipment for utility construction.
This condition could be encountered at the southwest portion of Drive "A" near
the intersection of Corintia Street.
PACIFIC SOILS ENGINEERING, INC.
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June 2, 2005
6.4 Subsurface Drainage
6.4.1 Canyon Subdrains
Canyon subdrains will be required on the project. The drains are to be placed
along the lowest alignment of unsuitable soils removals within the draw
areas. The approximate locations of anticipated drains are shown on the
enclosed grading plans. Final determination of subdrains requirements
should be made based on exposed geologic conditions. Canyon subdrains
should be constructed in accordance with the details shown on Plates G-l
and G-2 (Appendix E).
6.4.2 Heel Drains
Heel drains are recommended for proposed fill keyways and at the heel of all
MSB retaining walls. Proposed heel drain locations are provided on Plate 1.
Heel drains should be constructed in accordance with the details shown on
Plate G-3 (Appendix E).
6.5 Construction Staking, Subdrain and Backdrains Survey
It is recommended that backdrains and subdrains should be surveyed by the civil
engineer after approval by the geotechnical engineer/engineering geologist and prior
to the placement of fill. Toe stakes should be provided by the civil engineer in order
to verify required key dimensions and locations.
6.6 Earthwork Considerations
6.6.1 Compaction Standards
Fill and processed natural ground shall be compacted to a minimum relative
compaction of 90 percent as determined by ASTM Test Method: D 1557-91.
Compaction shall be achieved at slightly above the optimum moisture
content and as generally discussed in the attached Earthwork Specifications
and Grading Details (Appendix E).
6.6.2 Documentation of Removals and Drains
Removal bottoms, canyon subdrains, fill keys, backcuts, backdrains and their
outlets should be observed and approved by the engineering geologist and/or
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June 2, 2005
geotechnical engineer and documented by the civil engineer prior to fill
placement.
6.6.3 Treatment of Removal Bottoms
At the completion of removals, the exposed bottom should be scarified to a
depth of eight (8) to twelve (12) inches, moisture conditioned to above
optimum conditions and compacted in-place to the standards set forth in this
report.
6.6.4 Treatment of Saturated Removal Bottoms
In areas where partial alluvium removals are conducted, due to existing
improvements and/or property line restrictions and saturated alluvium
encountered prior to fill placement, the approved surface will require
stabilization. It is suggested that one (1) to two (2) feet of rock ranging in
size from three-quarters- (3/4) inch to eighteen (18) inches should be placed
upon the approved removal bottom. Once this material is placed, a geotextile
with similar properties to Mirafi 600X should be placed on top of the rock
blanket. Native soils can then be placed and compacted to project
specifications.
6.6.5 Fill Placement
After removals, scarification and compaction of in-place materials are
completed, additional fill may be placed. Fill should be placed in thin lifts
[eight- (8) inch bulk], moisture conditioned to slightly above the optimum
moisture content, mixed, compacted and tested as grading progresses until
final grades are attained.
6.6.6 Benching
Where the natural slope is steeper than 5-horizontal to 1-vertical and where
designed by the project geotechnical engineer or geologist, compacted fill
material should be keyed and benched into competent bedrock or firm natural
soil.
PACIFIC SOILS ENGINEERING, INC.
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June 2, 2005
6.6.7 Mixing
In order to provide thorough moisture conditioning and proper compaction,
processing (mixing) of materials is necessary. Mixing should be
accomplished prior to and as part of the compaction of each fill lift.
6.6.8 Fill Slope Construction
Fill slopes shall be overfilled to an extent determined by the contractor but
not less than two (2) feet measured perpendicular to the slope face, so that
when trimmed back to the compacted core, the required compaction is
achieved.
Compaction of each fill lift should extend out to the temporary slope face.
Backrolling during mass filling as intervals not exceeding four (4) feet in
height is recommended unless more extensive overfill is undertaken.
As an alternative to overfilling, fill slopes may be built to the finish slope
face in accordance with the following recommendations:
> Compaction of each fill lift shall extend to the face of the slopes.
> Backrolling during mass grading shall be undertaken at intervals not
exceeding four (4) feet in height. Backrolling at more frequent
intervals may be required.
> Care should be taken to avoid spillage of loose materials down the
face of the slopes during grading.
> At completion of mass filling, the slope surface shall be watered,
shaped and compacted by tracking with a bulldozer.
Proper seeding and planting of the slopes should follow as soon as practical,
to inhibit erosion and deterioration of the slope surfaces. Proper moisture
control will enhance the long-term stability of the finished slope surface.
6.6.9 Oversized Materials
Oversized rock material [i.e., rocks greater than eight (8) inches] could be
produced during the excavation of the design cuts and undercuts. Provided
that the procedure is acceptable to the homeowner and governing agency,
this rock may be incorporated into the compacted fill section to within five
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June 2, 2005
(5) feet of finish grade within residential areas and to one (1) foot below the
deepest utility in street areas. Maximum rock size in the upper portion of the
hold-down zone is restricted to eight (8) inches. Disclosure to the above rock
hold-down zone should be made to prospective homebuyers explaining that
excavations to accommodate swimming pools, spas and other appurtenances
will likely encounter oversize rock [i.e., rocks greater than eight (8) inches]
below five (5) feet. Rock disposal details are presented on Plate G-10,
Appendix E.
Rocks in excess of eight (8) inches in maximum dimension may be placed
within the deeper fills, provided rock fills are handled in a manner described
below. In order to separate oversized materials from the rock hold-down
zones, the use of a rock rake may be necessary.
6.6.9.1 Rock Blankets
Rock blankets consisting of a mixture of gravel, sand and rock to a
maximum dimension of two (2) feet may be constructed. The rocks
should be placed on prepared grade, mixed with sand and gravel,
watered and worked forward with bulldozers and pneumatic
compaction equipment such that the resulting fill is comprised of a
mixture of the various particle sizes, contains no significant voids,
and forms a dense, compact, fill matrix.
Rock blankets may be extended to the slope face provided the
following additional conditions are met: 1) no rocks greater than
twelve (12) inches in diameter are allowed within six (6) horizontal
feet of the slope face; 2) 50 percent (by volume) of the material is
three-quarters- (3/4) inch minus; and 3) backrolling of the slope
face is conducted at four- (4) foot verticals and satisfies project
compaction specifications (See Section 5.9.7).
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June 2, 2005
6.6.9.2 Rock Windrows
Rocks to maximum dimension of four (4) feet may be placed in
windrows in deeper fill areas in accordance with the details on Plate
G-10 (Appendix E). The base of the windrow should be excavated
an equipment-width into the compacted fill core with rocks placed
in single-file within the excavation. Sands and gravels should be
added and thoroughly flooded and tracked until voids are filled.
Windrows should be separated horizontally by at least fifteen (15)
' feet of compacted fill, staggered vertically and separated by at least
four (4) vertical feet of compacted fill. Windrows should not be
placed within ten (10) feet of finish grade, within two (2) vertical
feet of the lowest buried utility conduit in structural fills or within
fifteen (15) feet of the finish slope surface unless specifically
approved by the homeowner, geotechnical consultant and governing
agency.
6.6.9.3 Individual Rock Burial
Rocks in excess of four (4) feet but no greater than eight (8) feet
may be buried in the compacted fill mass on an individual basis.
Rocks of this size may be buried separately within the compacted
fill by excavating a trench and covering the rock with sand/gravel
and compacting the fines surrounding the rock. Distances from
slope face, utilities and building pad areas (i.e., hold-down depth)
should be the same as windrows.
6.6.9.4 Rock Disposal Logistics
The grading contractor should consider the amount of available
rock disposal volume afforded by the design when excavation
techniques and grading logistics are formulated. Rock disposal
techniques should be discussed and approved by the geotechnical
consultant and homeowner prior to implementation.
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June 2, 2005
6.6.9.5 Rock Windrows
Rocks larger than two (2) feet in maximum dimensions may be
placed in windrows in deeper fill areas in accordance with the
details on Plate G-10. The base of the windrow should be
excavated an equipment-width into the compacted fill core with
rocks placed in single-file within the excavation. Sands and gravels
should be added and thoroughly flooded and tracked until all voids
are filled.
Windrows should be separated by at least fifteen (15) feet of
compacted fill and staggered vertically by at least two (2) vertical
feet of compacted fill. Windrows should be held down below finish
grade as outlined in Section 6.7.8 or within fifteen (15) feet of the
finish slope surface unless specifically approved by the owner,
geotechnical consultant and governing agency.
In order to separate oversized materials from the rock hold-down
zones, the use of a rock rake may be necessary. The grading
contractor should consider the amount of available rock disposal
volume, afforded by the design when establishing his excavation
techniques and grading logistics. Rock disposal techniques should
be discussed and approved by the geotechnical consultant prior to
implementation.
6.7 Haul Roads
Haul roads, ramp fills and tailing areas should be removed prior to placement of fill.
6.8 Import Materials
Import materials, if required, should have similar engineering characteristics as the
onsite soils and should be approved by the soil engineer at the source prior to
importation to the site.
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June 2, 2005
7.0 DESIGN RECOMMENDATIONS
7.1 Structural Design
It is our understanding that the site will be graded for the purpose of constructing
single-family multi-story structures. Precise building products, loading conditions
and structural sitings are not currently available; however, it can be expected that for
typical structures and loading conditions, slab-on-grade post-tensioned or mat
foundations can be used. The design of slab-on-grade systems should be based upon
as-graded soil conditions and specific sitings.
Upon the completion of rough grading, finish-grade samples should be collected and
tested so as to provide specific recommendations as they relate to individual lots.
These test results and corresponding design recommendations will be presented in a
Final Rough Grading Report. Final foundation design recommendations should be
made based upon specific structure-sitings, loading conditions, and as-graded soil
conditions.
It is anticipated that the onsite soils used for compacted fill will exhibit "very low" to
"high" expansion potential when tested in accordance with U.B.C. Table 18-1-B.
The near-surface soils could vary between these extremes, depending upon the final
distribution of as-graded soils. For preliminary budgeting purposes, the following
foundation design parameters are presented.
7.1.1 Foundation Design
Structures should be supported on post-tensioned or mat slab/foundation
systems. The design of foundation systems should be based on as-graded
conditions as determined after grading completion. The following values
may be used in preliminary foundation design for budgeting purposes.
Allowable Bearing: 2000 Ibs./sq. ft. (assuming a minimum
embedment depth of 12-inches and a minimum
width of 12 inches).
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Lateral Bearing:
Page 26
250 Ibs./sq. ft. per foot of depth to a maximum of
2000 lbs./sq. ft.
Sliding Coefficient: 0.35
The above values may be increased as allowed by Code to resist transient
loads such as wind or seismic. Building code and structural design
considerations may govern depth and reinforcement requirements and should
be evaluated by a qualified engineer.
7.1.2 Seismic Design
Seismic design should be based on current and applicable building code
requirements and the parameters presented in Table 7.1. The parameters are:
1) soils profile types; 2) peak ground accelerations (PGA); 3) coefficients
for acceleration (Ca) and velocity (Cv); and 4) near source factors for
acceleration (Na) and velocity (Nv). The site occurs in seismic zone 4;
therefore, the seismic zone factor "Z" is 0.4. The nearest known active fault
is the Rose Canyon Fault. It is approximately 13.2 miles (21.3 kilometers)
from the project. These parameters are meant to be consistent with the UBC
(1997).
TABLE 7.1
UBC (1997) Seismic Parameters
Soil
Profile
Type PGA Z Ca Cv Na Nv
All Lots SD 0.35g 0.4 0.44Na 0.64NV 1.0 1.0
7.1.3 Settlement
hi addition to the potential effects of expansive soils, the proposed structures
should be designed in anticipation of differential settlements on the order of
three-eighths (3/8) inch in twenty (20) feet and a total settlement of three-
quarters (3/4) inch.
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June 2, 2005
Further, for buildings founded over or within a 1 : 1 (horizontal to vertical)
projection of mechanically stabilized earth (MSB) retaining walls (Lot 15
through 27), the proposed structures should be designed for consolidation of
the reinforced zone backfill, fill consolidation, foundation settlement and toe
settlement and lateral movement of the wall.
• Consolidation of reinforced zone backfill - The fill to be placed in
the reinforced zone will be compacted to a minimum of 90% of the
laboratory maximum density (ASTM D 1557). It is estimated that
this fill could undergo settlements on the order of one-half- (1/2) inch
to one (1) inch, although the interaction with the reinforcing material
could reduce this potential settlement source.
• Fill Consolidation - The fill placed behind the reinforced zone will
be compacted to a minimum of 90% of the laboratory maximum
density (ASTM D 1557). It is estimated that the fill placed behind
the reinforced zone could undergo settlements on the order of three-
eighths- (3/8) inch to one-half (1/2) inch.
• Foundation settlement and toe settlement - If the wall is founded on
bedrock, foundation settlement and toe settlement are anticipated to
be negligible. Settlement could occur in areas where the wall is
founded on fill and or saturated alluvium. Settlement in the fill areas
is anticipated to be on the order of three-eighths- (3/8) inch to one-
half- (1/2) inch and is expected to occur during wall construction.
For walls founded on compacted fills over left-in-place saturated
alluvium, settlement is on the order of one-half- (1/2) inch to one (1)
inch and is expected to occur during wall construction.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 28
June 2, 2005
• Lateral Movement - Estimates of the lateral movement should be
determined by the wall design engineer.
Accordingly, the structural design engineer should provide specific designs
for the foundations differential settlement and the expansive potential of the
specific lot.
7.1.4 Post-Tensioned Slab/Foundation Design
Table 7.2 presents preliminary design recommendations that may be
implemented by the structural engineer when post-tensioned slab/foundation
systems are utilized in the building construction based on Section 1816 and
1817 of the 1997 UBC. It is suggested minimally, that where buildings are
founded within a 1 : 1 (horizontal to vertical) influence of MSB wall systems,
a Category II foundation system should be used. Final determination as to
foundation design for this condition should be determined by the structural
engineer (see Section 7.1.3).
PACIFIC SOILS ENGINEERING, INC.
Work Order 40103 6
June 2, 2005
Page 29
TABLE 7.2
POST-TENSIONED FOUNDATION DESIGN CRITERIA
SOIL
CATEGORY
I
II
III
EXPANSION
POTENTIAL
Very Low
to Low
Medium
High
CENTER LIFT
All Per
Beam Co
Em (ft.)
5.5
5.5
6.0
imeter
nditions
Ym (in.)
2.42
2.75
4.6
EDGE LIFT
18-
Embe
Em (ft.)
3.50
3.50
3.75
Inch
dment
Ym (in.)
0.43
0.58
0.61
24-1
Embec
Em (ft.)
3.5
3.50
3.75
neb.
merit
Ym(in.)
0.38
0.51
0.67
30-1
Embe
Em (ft.)
3.5
3.5
3.75
neb.
dment
Ym (in.)
0.33
0.44
0.58
Footing/Slab Dimensions
The footing width, depth and the structural slab-on-grade thickness shall be as specified by the structural
engineer based upon the soil parameters provided by PSE and the requirements of the most current UBC.
Under-Slab Requirements
A 10-mil (minimum) polyvinyl membrane should be placed below all slabs-on-grade within living and
moisture sensitive areas. This membrane should be covered with a minimum of two (2) inches of clean
sand. This membrane should also be underlain with two (2) inches of clean sand.
Slab Subgrade Moisture Requirements
Very Low to Low
Medium
High
Minimum of 1 10 percent of optimum moisture at least 24 hours prior to
placing concrete to a depth of 12 inches.
Minimum of 130 percent of optimum moisture at least 24 hours prior to
placing concrete to a depth of 12 inches.
Minimum of 140 percent of optimum moisture at least 48 hours prior to
placing concrete to a depth of 12 inches.
Footing Embedment
If exterior footings adjacent to drainage swales are to exist within five (5) feet horizontally of the swale, the
footing should be embedded sufficiently to assure embedment below the swale bottom is maintained.
Footings adjacent to slopes should be embedded such that at least five (5) feet are provided horizontally
from edge of the footing to the face of the slope.
7.1.5 Mat Slab Recommendations
Mat excavations should be cleared of any loose soil, soft spots or debris and
kept moist prior to concrete placement. Standing water should not be
allowed to collect in mat excavations. If ponding does occur, excavations
should be pumped free of standing water and checked for soft zones. Prior to
concrete placement, any soft or disturbed zones should be overexcavated and
replaced with compacted fill or lean concrete.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 30
June 2, 2005
We recommend a modulus of subgrade reaction (Kvi) of 150 tons per cubic
foot (tcf). For a loaded area that has a width of B, in feet, modulus of
subgrade reaction K can be calculated using the equation K- Kvi/B.
Minimum Slab Thickness: 8 inches (Full)
Under Slab Treatment: Subgrade soils to contain at least 120 percent of
optimum moisture content to a depth of 12 inches
Category I Mat underlain by 2 inches of sand on grade
(Very Low to Low Expansion)
Categories II and III Mat with 12-inch perimeter footing and slab
(Medium to High Expansion) underlain by 2 inches of sand
The mat may be designed using allowable bearing pressure of 2,000 psf for
dead loads, 3,000 psf for dead plus sustained live loads and 4,000 psf for
total loads, including wind and seismic forces. Resistance of mats to lateral
loads can be derived from: 1) passive resistance acting on the faces of
foundations elements perpendicular to the direction of motion; and
2) friction acting between the bottom of footings and the supporting
subgrade. The values used in Section 7.1.1 for lateral bearing and friction
can be used.
7.1.6 Deepened Footings and Structural Setbacks
It is generally recognized that improvements constructed in proximity to
natural slopes or properly constructed, manufactured slopes can, over a
period of time, be affected by natural processes including gravity forces,
weathering of surficial soils and long-term (secondary) settlement. Most
building codes, including the Uniform Building Code (UBC), require that
structures be set back or footings deepened, where subject to the influence of
these natural processes.
For the subject site, where foundations for residential structures are to exist
in proximity to slopes, the footings should be embedded to satisfy the
requirements presented in Figure 5.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Page 31
FIGURE 5
Setback Dimensions (UBC. 1997)
Hfi NBUT NEED NOT
EXCEED 15 FT.
MAX.
FACE OF
FOOTING
H/3 BUT NEED NOT
EXCEED 40 FT.MAX.
7.2
7.1.7 Backyard Improvements
Backyard improvements, such as patio slabs, pools and perimeter walls,
should also be designed in consideration of potential creep on descending
slopes and in consideration of the as-graded expansive soil characteristics.
Footings for perimeter walls at the top of natural slopes should be founded in
competent/unweathered bedrock.
Walls should be structurally separated at appropriate intervals. Wall footing
excavations should be observed by the project soils engineer/engineering
geologist.
Retaining Wall Design
Retaining walls should be founded on compacted fill or bedrock. Foundations may
be designed in accordance with the recommendations presented in Section 7.1.1. In
general, conventional walls can be designed to retain either native materials or select
granular backfill, although the design for non-"free-draining" and expansive native
material will produce a relatively costly wall system. Due to the fact that some of
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Page 32
the native onsite soils are relatively fine-grained and expansive, specifications for
the quality of backfill soils should be defined. It should be anticipated that suitable
backfill material will have to be imported or selectively produced from onsite
sources.
Conventional walls constructed with select granular backfill or native soils can be
designed to resist lateral pressures that are developed by a fluid as presented on
Table 7.3. As depicted on the accompanying retaining wall detail (Figure 6), the
select material should extend a minimum width (behind the wall) of one-half (1/2)
the wall height and should be capped with a layer of approximately one (1) foot
thickness of native soil.
FIGURE 6
RETAINING WALL BACKFILL
N.T.S.
PROVIDE DRAINAGE
SWALE
NATIVE OR SELECT i '
BACKFILL .' ; SELECT
BACKFILL
DRAIN LATERALLY,
OR PROVIDE WEEP
HOLES
1 l\ AS REQUIRED
TO DRAIN
1' "
OR AS MODIFIED
BY A SPECIFIC REPORT
(T) 4 INCH PERFORATED PVC, SCHEDULE 40, SDR 35 OR APPROVED ALTERNATE, PLACE
^ PERFORATIONS DOWN AND SURROUND WITH 4 CU. FT. PER FT. OF 3/4 INCH
ROCK OR APPROVED ALTERNATE AND MIRAFI 140 FILTER FABRIC OR APPROVED
EQUIVALENT
(?) 6 INCH PERFORATED PVC SCHEDULE 40, SDR 35 OR APPROVED ALTERNATE, PLACE
PERFORATIONS DOWN AND SURROUND WITH 4 CU FT OF 3/4 INCH ROCK OR
APPROVED ALTERNATE AND MIRIFI 140 FILTER FABRIC OR APPROVED EQUIVALENT.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 33
June 2, 2005
7.3 Mechanically Stabilized Earth (MSE) Retaining Wall
An MSE retaining wall is proposed subjacent to the pad area on Lot 16 and at the
easterly end of the cul de sac. These types of retaining walls typically have a
geotextile reinforcing material behind the wall. The width of this material is
typically equal to 0.7 to 1.0 of the height of the wall.
Due to differential engineering characteristics of the soil that is reinforced with
geotextile material versus the un-reinforced fill soils on the pad, it is recommended
that structures not be placed over the soil that is reinforced with the geotextile
material, hi lieu of a setback zone, design of the structure should consider the
potential settlement (see Section 7.1.3).
For preliminary design of MSE wall systems, the following design parameters are
presented:
Foundation Retained and Reinforced Zone
Compacted Fill
(j) -29°
C= 150 psf
y=130 pcf
7.4 Other Design and Construction Considerations
> The design loads presented in Table 7.3 are to be applied on the retaining
wall in a horizontal fashion. Friction between wall and retained soils should
not be allowed in the retaining wall analyses.
> Additional allowances should be made in the retaining wall design to account
for the influence of construction loads, temporary loads and possible nearby
structural footing loads. Unit weights of 125 pcf and 130 pcf may be used to
model the dry and wet density of onsite compacted fill materials.
> Select backfill, imported or granular, should be granular, structural quality
backfill with a sand equivalent of 20 or better and an ASCE Expansion Index
of 20 or less. The backfill must encompass the full active wedge area.
> No backfill should be placed against concrete until minimum design
strengths are achieved in compression tests of cylinders.
> Footing excavations for retaining walls should be observed by the project soil
engineer or his representative.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Page 34
Backfill should be compacted to a minimum of 90 percent of the laboratory
maximum density at or slightly above optimum moisture as per ASTM:D
1557-91.
It should be noted that the bearing capacity and passive resistance values
presented in Section 7.1.1 are based on level conditions at the toe. Modified
design parameters can be presented for retaining walls with sloped conditions
at the toe.
TABLE 7.3
SELECT BACKFILL
Level Backfill
Coefficient of Active Pressure:
Coefficient of Passive Pressure:
Coefficient of at Rest Pressure:
2 : 1 Backfill
Coefficient of Active Pressure:
Coefficient of Passive Pressure:
Descending
Coefficient of At Rest Pressure:
Rankine
Coefficients
Ka = 0.31
Kp-3.25
K^ - 0.47
Rankine
Coefficients
Ka - 0.47
Kp (-)= 1.23
1C, = 0.72
Equivalent Fluid
Pressure (psf/lin.ft.)
40
423
61
Equivalent Fluid
Pressure (psf/lin.ft.)
61
161
94
7.4.1 Utility Trench Excavation
All utility trenches should be shored or laid back in accordance with
applicable OSHA standards. Excavations in bedrock areas should be made
in consideration of underlying geologic structure. Pacific Soils Engineering,
Inc. should be consulted on these issues during construction.
7.4.2 Utility Trench Backfill
Mainline and lateral utility trench backfill should be compacted to at least 90
percent of maximum dry density as determined by ASTM:D-1557-91.
Onsite soils will not be suitable for use as bedding material but will be
suitable for use in backfill, provided oversized materials are removed. No
surcharge loads should be imposed above excavations. This includes spoil
piles, lumber, concrete trucks or other construction materials and equipment.
PACIFIC SOILS ENGINEERING, INC.
Work Order 40103 6
June 2, 2005
Page 35
7.5
7.6
Drainage above excavations should be directed away from the banks. Care
should be taken to avoid saturation of the soils.
Compaction should be accomplished by mechanical means. Jetting of native
soils will not be acceptable. Under-slab trenches should also be compacted
to project specifications. If native soils are used, mechanical compaction is
recommended. If select granular backfill (SE > 30) is used, compaction by
flooding will be acceptable. The soil engineer should be notified for
inspection prior to placement of the membrane and slab reinforcement. The
use of a double layer of mesh across under-slab plumbing trenches is
considered an acceptable alternative to compaction of sand backfill.
Preliminary Pavement Design
Final pavement design should be made based upon sampling and testing of post-
grading conditions. For preliminary design and estimating purposes, the following
pavement structural sections can be used for the range of likely traffic indices. The
structural sections are based upon an assumed "R"-value of 30.
TABLE 7.4
PAVEMENT SECTION
Traffic
Index
5
6
7
8
AC"1- ;• .
3
4
4
5
AB
6
7
10
11
Note: AC - Asphaltic Concrete, AB - Aggregate Base
Sub grade soils should be recompacted to at least 90 percent of maximum density as
determined by ASTM:D-1557. Aggregate base materials should be compacted to at
least 95 percent of maximum density as determined by California Test 216.
Chemical and Corrosion Potential
Chemical and corrosion testing and analyses should be conducted on the final
distribution of soils after precise grading operations are completed. Currently, the
existing near surface exhibits "negligible" soils sulfate concentrations. However,
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 36
June 2, 2005
some fertilizers have been known to leach sulfates into soils otherwise containing
"negligible" sulfate concentrations and increase the sulfate concentrations to
potentially detrimental levels. Accordingly, it is suggested that foundations for the
single-family structures be designed for a "moderate" sulfate concentration in
accordance with Table 19-A-4 (UBC 1997). Therefore, the concrete should have a
minimum compressive strength of 4000 psi and a maximum water/cement ratio of
0.5. The results of chemical testing are presented in Appendix C.
8.0 SLOPE AND LOT MAINTENANCE
Maintenance of improvements is essential to the long-term performance of structures and
slopes. Although the design and construction during mass grading is planned to create
slopes that are both grossly and surficially stable, certain factors are beyond the control of
the soil engineer and geologist. The homeowners must implement certain maintenance
procedures.
The attached "Homeowners Maintenance and Improvement Considerations" presented in
the Appendix F may be included as part of the sales packet to educate the homeowners in
issues related to slopes, maintenance, backyard improvements, etc. The following
recommendations should also be implemented.
8.1 Slope Planting
Slope planting should consist of ground cover, shrubs and trees that possess deep,
dense root structures and require a minimum of irrigation. The residents or
Homeowner Association should be advised of their responsibility to maintain such
planting.
8.2 Lot Drainage
Roof, pad and lot drainage should be collected and directed away from structures
and slopes and toward approved disposal areas. Design fine-grade elevations should
be maintained through the life of the structure or if design fine grade elevations are
altered, adequate area drains should be installed in order to provide rapid discharge
of water, away from structures and slopes. Residents should be made aware that
they are responsible for maintenance and cleaning of all drainage terraces,
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 37
June 2, 2005
downdrains and other devices that have been installed to promote structure and slope
stability.
8.3 Slope Irrigation
The resident, homeowner and Homeowner Association should be advised of their
responsibility to maintain irrigation systems. Leaks should be repaired immediately.
Sprinklers should be adjusted to provide maximum uniform coverage with a
minimum of water usage and overlap.
Overwatering with consequent wasteful run-off and ground saturation should be
avoided. If automatic sprinkler systems are installed, their use must be adjusted to
account for natural rainfall conditions.
8.4 Burrowing Animals
Residents or homeowners should undertake a program for the elimination of
burrowing animals. This should be an ongoing program in order to maintain slope
stability.
9.0 FUTURE PLAN REVIEWS
This report represents a geotechnical review of 40-scale grading plans. As the project
design progresses, site-specific geologic and geotechnical issues need to be considered in
the design and construction of the project. Consequently, future plan reviews may be
necessary. These reviews may include reviews of:
> Precise grading plans.
> Foundation plans.
> Retaining wall plans
These plans should be forwarded to the project geotechnical engineer/geologist for
evaluation and comment, as necessary.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036 Page 38
June 2, 2005
10.0 LIMITATIONS
The recommendations presented in this report are based on the assumption that an
appropriate level of field review will be provided by geotechnical engineers and engineering
geologists who are familiar with the design and site geologic conditions. That field review
should be sufficient to confirm that geotechnical and geologic conditions exposed during
grading are consistent with the geologic representations and corresponding
recommendations presented in this report. Pacific Soils Engineering, Inc. should be notified
of any pertinent changes in the project plans or if subsurface conditions are found to vary
from those described herein. Such changes or variations may require a re-evaluation of the
recommendations contained in this report.
The geologic data presented on the exhibits represent selective geologic data that PSE
considers representative of site conditions. More comprehensive geologic data are
contained within the boring logs and log of trenches contained herein and within the
referenced reports.
The data, opinions and recommendations of this report are applicable to the specific design
of this project as discussed in this report. They have no applicability to any other project or
to any other location and any and all subsequent users accept any and all liability resulting
from any use or reuse of the data, opinions and recommendations without the prior written
consent of Pacific Soils Engineering, Inc.
Pacific Soils Engineering, Inc. has no responsibility for construction means, methods,
techniques, sequences or procedures, or for safety precautions or programs in connection
with the construction, for the acts or omissions of the CONTRACTOR or any other person
performing any of the construction, or for the failure of any of them to carry out the
construction in accordance with the final design drawings and specifications.
PACIFIC SOILS ENGINEERING, INC.
APPENDIX A
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
REFERENCES
Blake, T. F., 1989-2000a, EQFAULT, for Windows Version 3.0, computer program for the
deterministic prediction of peak horizontal acceleration from digitized California faults.
Blake, T. F., 1989-2000b, EQSEARCH, for Windows Version 3.0, computer program for the
estimation of peak horizontal acceleration from digitized California faults.
Blake, T. F., 1989-2000c, FRISKSP, for Windows Version 4.0, proprietary computer source
code for probabilistic acceleration determination.
Boore, D. M., Joyner, W. B., and Fumal, T. E., 1997, Equations for estimating horizontal
response spectra and peak acceleration from western North American earthquakes: A
summary of recent work, Seismological Research Letters, vol 6.8, No. 1, p. 128-153.
California Division of Mines and Geology, 1997, Guidelines for evaluating and mitigating
seismic hazards in California: Department of Conservation, Special Publication 117,
74pp.
Gregory, Garry H., 2001, GSTABL7 (version 2.0) with STEDwin, Slope Stability Analysis
System.
Hart, E. W., 1994, Fault-rupture hazard zones in California: California Division of Mines and
Geology, special publication 42, 1992, revised edition, 34 p.
Jennings, C. W., 1994, Fault activity map of California and adjacent areas: California Division
of Mines and Geology, California geologic map data series, map no. 6, scale 1:750,000.
Kennedy, M.P and Tan S.S., 1996, Geologic Maps of the Northwestern Part of San Diego
County, California: California Division of Mines and Geology open file report 96-02.
Petersen, M. D., Bryant, W. A., Cramer, C. H., Cao, T., Reichle, M. S., Frankel, A. D.,
Lienkaemper, J. J., McCrory, P. A., and Schwartz, D. P., 1996, Probabilistic seismic
hazard assessment for the State of California: California Division of Mines and
Geology, open file report 96-08, 59 p.
Uniform Building Code, 1997, International Conference of Building Officials, 3 volumes:
Whittier, California.
PACIFIC SOILS ENGINEERING, INC.
APPENDIX B
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
DESCRIPTION OF SUBSURFACE INVESTIGATION
PSE's current subsurface investigation was performed in February of 2005. It consisted of
excavation of eight (8) test pits and the drilling of five (5) hollow-stem borings. The test ranged
from seven and one-half (7.5) feet to fourteen (14) feet below existing grades. The borings
ranged from ten and one-half (10.5) feet to twenty-six (26) feet below existing grades. The
approximate locations of all test pits and hollow-stem borings are shown on Plate 1.
Selected representative bucket and ring samples were obtained from the exploratory excavations
and delivered to PSE's laboratory for testing and analysis.
PACIFIC SOILS ENGINEERING, INC.
UNIFIED SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS
<*-! 2-
I !»~gQ to
C o
fi -O£ o
te **
•si *>B SS N</5 S.e
1? * €>
t<- -5 c\j
% o
I z
i H
*n
* i> i ™~
I * t? « "~ 8
| * •• * a s ^
^~ *l J1"! °
If ll 1*1
«:l|?! "-*
^ijji1 *§|MP* H^°
O -"5 inD |
o 5
£ -i Ji
(75
*i!
"? "D w
lo ""
HIGHLY ORGANIC SOILS
GROUP
SYMBOLS
T^
^^1$
$
• •• *• •
• •
*• •y s*sgt
GW
GP
GM
GC
SW
SP
SM
SC
i
^ Af // // /t~^.
ML
CL
c\\\j\-
MH
CH
UH
PI
TYRCAL NAMES
Well-groo>d gravels, grovel sond mixtures,
little or no fines
Poorly -graded grovels, grovel-sand mixtures,
little or no fines
Silty grovels, gravel-sand-silt mixtures
Clayey grovels, gravel -sand-silt mixtures
Wen-graded sands, gravelly sands, little or
no fines
Poorly - graded sands, gravelly sands, little or
no fines
Silty sands, sand-silt mixtures
Clayey sonds, sond -cloy mixtures
Inorganic silts and fine sands, rock (lour
silty or clayey (in* sands or clayey
silts with slight plasticity
harganic cloys of bw to medium plasticity,
gravelly cloys, sandy cbys, silty cloys, lean cloys
Organic silts ond organic silty cloys of
low plasticity
Inorganic silts, micaceous or diatomoceous
fine sandy or silty soils, elastic silts
Inorganic cloys of high plasticity, fat clayt
Organic clays of medium
organic lilts
to high ptatfieity,
Peat and other highly organic soils
FIELD IDENTIFICATION PROCEDURES
Wide ronge groin sizes and substantial amounts of all
intermediate particle sizes
Predominately one size or o range of sizes with some
intermediate sizes missing
Nonplastic fines or fines wrrh low plasticity (far idwiti-
procedures see M. below)
Ptoslic fines (for identification procedures set CL below)
Wide range in groin sizes and substantial amounts of
all intermediate particle sizes
Predominately one
some intermediate
size or o ronge of
sizes missing
sizes with
Nonplastic fines or fines with low plasticity
(for identification procedures see ML below)
Plastic fines (for identification procedures see CL below)
IDENTIFICATION PROCEDURES
on fraction smaller than No. 40 sieve size
Dry Strength
( crushing
characteristics)
None to slight
Medium to high
Slight to
medium
Slight to
medium
High to very
high
Medium to high
Dilotancy
(reaction to
shaking )
Quick to sbw
None to very
Stow
Slow to none
None
None to very
slow
Toughness
(consistency
near PL)
None
Medium
Slight to
medium
Slight to
medium
High
Slight to
medium
Readily Identified by color, odor, spongy, feel
ond frequently by fibrous texture
BOUNDARY CLASSIFICATIONS Safe poaeung ctoroctvishcs of two groups art designated by arrimolcni of flnx* cymbals
PARTICLE SIZE LIMITS
SILT OR CLAY
SAND
RNE MEDUM COARSE
GRAVEL
FINE COARSE
• COBBLES 1it
BOULDERS
No 200 No «O No C No4 V4 n S« (12 in)
US STANDARD SIEVE SIZE
CONSISTENCY CLASSIF CATION
GRANULAR SOIL COHESIVE SOIL
Very loose Very soft
Loose Soft
Moderately dense Firm
Medium dense Stiff
Dense Very (tiff
Very dense Hard
Ffefennce>
Tta Urafixj So OoMtenw SyttOT, Corn of
EngJnxrv US Ann, TtOntti Memorandum No J-J57,
vbkim. 1, Math, I9H (Pw,«Md April. 19601
BEDROCK MOISTURE CONDITION OTHER SYMBOLS
Dry R" Undisturbed sample
Slightly moist B- Bulk sample
Soft Moist SZ Groundwater
Moderately hard Wet £ Groundwater seepage
Hard Saturated
Very hard
PACIFIC SOILS ENGINEERING, INC.
PLATE A
PROJECT NO. 401036
DATE STARTED 2/9/05
DATE FINISHED 2/9/05
DRILLER Martini Drilling
TYPE OF DRILL RIG Hollow Stem Auger
GEOTECHNICAL BORING LOG
PROJECT NAME LA COSTA
SHEET 1 OF 1
GROUND ELEV.
GW DEPTH (FT)
DRIVE WT.
DROP
140 Ib
BORING DESIG.
LOGGED BY
NOTE
HS-01
DMA
18 in.
-p ^^
0- <DLULL_
-
5-
-
10-
-
-
15-
-
-
20-
-
-
25-
LU
LU
^UJ
15:
3H
R
R
R
K
R BLOWS7/12/13
10/18/21
'/
//'/y
9/10/19
8/12/20
[
?
'939/50 for 5.
4 1/2" a LITHOLOGYy/////,w.
«9«j
^GROUPSYMBOLSM
SC
SAMPLE TYPES:
US RING (DRIVE) SAMPLE
OH SPT (SPLIT SPOON) SAMPLE
LS BULK SAMPLE LTl TUBE SAMPLE
GEOTECHNICAL DESCRIPTION
ARTIFICIAL FILL - UNDOCUMENTED (afu): SILTY SAND, fine to
medium grained, light gray, slightly moist, moderately dense.
@ 4.5 ft. light brown, moist, moderately dense. _
@ 8 ft. light gray, fine grained.
-
ALLUVIUM (Qal): CLAYEY SAND, fine to medium grained, dark
brown, moist, stiff.
SANTIAGO FORMATION (Tsa): SANDSTONE, mottled red, grav.
brown, soft, moist, highly weathered.
@ 19 ft. oxidized, calcium carbonates.
GRANITIC BEDROCK (Kar): mottled red, gray, brown, hard,
fractured, oxidized.
TOTAL DEPTH = 26 FT.
NO WATER
NO CAVING
Backfilled with approximateiy 9 cu. ft. of hydrated bentonite according
to County of San Diego Department of Environmental Health, Land,
and Water Quality Division guidelines.MOISTURECONT(%)9.4
10.9
15.7
14.5
4.9
QQ
108
110
114
114 SAT- IURATION(%)47
57
93
85 OTHERTESTShydro
consol
hydro
-
^SEEPAGE Hs9 ENGINEERING, INC.
GEOTECHNICAL BORING LOG SHEET 1 OF 1
PROJECT NO.
DATE STARTED
DATE FINISHED
DRILLER
401036 PROJECT NAME LA COSTA
2/9/05 GROUND ELEV. BORING DESIG.HS-02
2/9/05 GW DEPTH (FT) 15 LOGGED BY DMA
Martini Drilling DRIVE WT. 140 Ib NOTE
TYPE OF DRILL RIG Hollow Stem Auger
LULL^
10-
UJ
UJ SAMPLETYPER
R
R
R
R BLOWS6/8/1 1
8/15/21
6/11/18
9/10/15
25/50 for
6"LITHOLOGYw
y^%/
fjfj>&$'GROUPSYMBOLSM
CL
SM
SC
1
SAMPLE TYPES:
DH RING (DRIVE) SAMPLE
D-D SPT (SPLIT SPOON) SAMPLE
[B BULK SAMPLE CD TUBE SAMPLE
DROP 18 in.
GEOTECHNICAL DESCRIPTION
ARTIFICIAL FILL - UNDOCUMENTED (afu): SILTY SAND, fine
grained, light brown, moderately dense, dry to slightly moist.
@ 4 ft. SANDY CLAY, light brown gray, moist, stiff, scattered gravel
ALLUVIUM (Qal): SILTY SAND, fine to medium grained, brown,
medium dense, moist, scattered gravel grains.
@ 12 ft. CLAYEY SAND, fine grained, brown, stiff, moist.
SANTIAGO FORMATION (Tsa): SANDSTONE, mottled qray,
orange, brown, soft, moist, weathered.
@ 14 5 ft. groundwater.
GRANITIC BEDROCK (Kqr): liqht red, hard saturated, weathered.
@ 20 ft. difficult to drill.
-x(3>21 ft. drill refusal /-
TOTAL DEPTH = 21 FT.
NO CAVING
GROUNDWATER @ 14.5 FT.
Backfilled with approximately 7 cu. ft. of hydrated bentonite according
to County of San Diego Department of Environmental Health, Land,
and Water Quality Division guidelines.MOISTURECONT (%)14.8
11.2
16.1
25.5
10.6
I-
ccujQQ
104
114
112
98
H-~
67
65
89
97 OTHERTESTShydro
chem
ushr
hydro
I GROUNDWATER •R9IH DAr^lCir* COII C
^ SEEPAGE IT-TSI KAUINU 5>UILb
nfSJM ENGINEERING, INC.
KEEal PLATE B-2
GEOTECHNICAL BORING LOG SHEET 1 OF 1
PROJECT NO. 401036
DATE STARTED 2/9/05
DATE FINISHED 2/9/05
DRILLER Martini Drilling
TYPE OF DRILL RIG Hollow Stem Auger
PROJECT NAME LA COSTA
GROUND ELEV.
GW DEPTH (FT)
DRIVE WT. 140lb
DROP 18 in.
BORING DESIG.
LOGGED BY
NOTE
HS-03
DMA
I — "S
LLJLL^
_
5-
'10-
LU
LU SAMPLETYPER
R BLOWS5/10/14
8/8/1 1
50/ for
2"LITHOLOGYGROUPSYMBOLSM
SAMPLE TYPES:
LJU RING (DRIVE) SAMPLE
[E SPT (SPLIT SPOON) SAMPLE
E] BULK SAMPLE CD TUBE SAMPLE
GEOTECHNICAL DESCRIPTION
ARTIFICIAL FILL- UNDOCUMENTED (afu): SILTY SAND, fine to
medium grained, light brown, slightly moist, moderately dense.
@ 5 ft. moist, grey.
_^@ 10ft. drill refusal. ^
TOTAL DEPTH = 10.5 FT.
NO WATER
NO CAVING
Backfilled with approximately 4 cu. ft. of hydrated bentonite according
to County of San Diego Department of Environmental Health, Land,
and Water Quality Division guidelines.MOISTURECONT(%)£ LU
DQ SAT-URATION(%)OTHERTESTS-
^SEEPAGE HSu ENGINEERING, INC.
•Sal PLATE B-3
GEOTECHNICAL BORING LOG SHEET 1 OF 1
PROJECT NO.
DATE STARTED
DATE FINISHED
DRILLER
401036 PROJECT NAME LA COSTA
2/9/05 GROUND ELEV. BORING DESIG.HS-04
2/9/05 GW DEPTH (FT) 20 LOGGED BY DMA
Martini Drilling DRIVE WT. 140 Ib NOTE
TYPE OF DRILL RIG Hollow Stem Auger
tfLULLQ —
5-
10-
15-
20-
25-
LU
LU
LU
CO
R
R
R
R
R
B
R BLOWS7/12/22
7/12/21 Z
yyyyyyyyyI
4/8/17
7/10/13
7/15/30
14/16/31 LITHOLOGYI1 GROUPSYMBOLSM
CL
SAMPLE TYPES:
LU RING (DRIVE) SAMPLE
LU SPT (SPLIT SPOON) SAMPLE
LU BULK SAMPLE LTD TUBE SAMPLE
DROP 18 in.
GEOTECHNICAL DESCRIPTION
ARTIFICIAL FILL - UNDOCUMENTED (afu): SILTY SAND, fine to
medium grained, light gray, slightly moist, moderately dense.
@ 4 ft. moist, light brown, medium dense.
lALLUVIUM (Qal): SANDY CLAY, sand portion is fine grained, f
Vbrown, moist, stiff, some silt, scattered medium grains, slight /
\oxidation. /
-
SANTIAGO FORMATION (Tsa): SANDSTONE, brown qrav,
moist, soft, highly weathered.
@ 20 ft. light brown, saturated, soft.
@ 20.2 ft. groundwater.
@ 25 ft. mottled gray, brown, red, soft to moderately hard, saturated,
calcium carbonates.
TOTAL DEPTH = 26.5 FT.
NO CAVING
GROUNDWATER @ 20.2 FT.
Backfilled with approximately 9 cu. ft. of hydrated bentonite according
to County of San Diego Department of Environmental Health, Land,
and Water Quality Division guidelines.MOISTURECONT (%)15.3
10.8
18.9
20.5
17.5
ft
LK LU
QD
106
108
109
103
110 SAT-URATION(%)72
53
96
91
92 OTHERTESTSushr
hydro
max ei
hydro
i I EEPANGDEWATER iSS PACIFIC SOILS
HJ9N ENGINEERING, INC.
GEOTECHNICAL BORING LOG SHEET 1 OF 1
PROJECT NO.
DATE STARTED
DATE FINISHED
DRILLER
TYPE OF DRILL RIG
401036
2/9/05
2/9/05
Martini Drilling
Hollow Stem Auger
PROJECT NAME LA COSTA
GROUND ELEV.
GW DEPTH (FT)
DRIVE WT. 140lb
DROP 18 in.
BORING DESIG.
LOGGED BY
NOTE
HS-05
DMA
frTuQ_ <uLULL
Q"
_
:
5-
10-
-
~
15-
-
on
UJ
LLJ SAMPLE ITYPER
K
K
R
R
S BLOWS7/13/12
5/6/13
15/21/22
13/50 for
6"
30/50 for
4 1/2"
27/31/39 LITHOLOGYGROUPSYMBOLSM
^
SAMPLE TYPES:
LH RING (DRIVE) SAMPLE
LI] SPT (SPLIT SPOON) SAMPLE
LH BULK SAMPLE CD TUBE SAMPLE
GEOTECHNICAL DESCRIPTION
ARTIFICIAL FILL - UNDOCUMENTED (afu)SILTY SAND, fine to
medium grained, light gray, slightly moist, moderately dense.
@ 4 ft. moist, light brown.
@ 6 ft brown, scattered coarse grains
@ 10 ft. mottled red, gray, brown, dense, oxidized, increase in coarse
grains.
SANTIAGO FORMATION (Tsa): SANDSTONE/SILTSTONE,
brown, moist, soft, weathered, oxidized.
@ 15 ft. moderately hard.
@ 18 ft. mottled gray, red, moist, hard, oxidized.
@ 19ft. seepage.
@ 20 ft. mottled gray, red, brown, hard, wet, weathered, oxidized.
TOTAL DEPTH = 23.5 FT.
NO CAVING
SEEPAGE® 19 FT.
Backfilled with approximately 7 cu. ft. of hydrated bentonite according
to County of San Diego Department of Environmental Health, Land,
and Water Quality Division guidelines.
I GROUNDWATER
>»» SEEPAGE MOISTURECONT(%)13.9
97
14.0
12.7
It
>2KUJQQ
106
11R
116
120
z,of
66
fin
88
89 OTHERTESTS-
ifSS\ PACIFIC SOILS
Hgdl ENGINEERING, INC.
Work Order 401036
June 2, 2005
401036Work Order
Date Excavated 2-9-05
Excavated by EC
Equipment 310 John Deere w/12" bucket
TABLE I
LOG OF TEST PITS
Test
Pit No.Depth (ft.) USCS Description
TP-1 0.0-7.5 SM
7.5-8.5
8.5-14.0
CL
ARTIFICIAL FILL - UNDOCUMENTED (afiO:
SILTY SAND, slightly moist, soft; contains some
medium to coarse sand grains with common gravel
and cobbles; rootlets.
ALLUVIUM (OaH: SANDY CLAY, fine-grained,
medium reddish brown, slightly moist, firm.
SANTIAGO FORMATION (Tsa): SILTY
SANDSTONE, fine-grained, mottled olive green
and olive gray with orange oxidation, slightly moist,
moderately hard; highly weathered; clean, white
micro-sheared clay at base.
TOTAL DEPTH 14.0 FT.
NO WATER, NO CAVING
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
TABLE I continued
LOG OF TEST PITS
Test
Pit No. Depth ffl.) USCS Description
TP-2 0.0-3.5 SM ARTIFICIAL FILL - UNDOCUMENTED (afu):
SILTY SAND, fine-grained, light tan gray, moist,
loose.
SC @ 1.0 ft. CLAYEY SAND, fine-grained with
medium-grained sand to cobble clasts, medium
brown, mottled with dark reddish brown, light gray
and orange, slightly moist, very stiff; contains 1"
pieces of asphalt.
3.5-6.5 SC ALLUVIUM (Pal): CLAYEY SAND, fine-
grained, dark brown, slightly moist, very stiff.
@ 6.0 ft. calcium carbonate; contains some medium
to coarse sand grains and gravel; rootlets.
6.5-13.0 SANTIAGO FORMATION (Tsa): SANDY
SILTSTONE, fine-grained, medium gray, slightly
moist, moderately weathered, moderately hard.
SILTY SANDSTONE, fine-grained, mottled tan
and light brown.
13.0-14.0 GRANITIC BEDROCK (Kgr): GRANITE,
medium crystalline, medium orangish brown,
slightly moist, moderately weathered, moderately
hard.
TOTAL DEPTH 14.0 FT.
NO WATER, NO CAVING
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
TABLE I continued
LOG OF TEST PITS
Test
Pit No.Depth (ft.") USCS Description
TP-3 0.0-1.5 SC
1.5-5.5
5.5-7.5
TOPSOIL (No Map Symbol): CLAYEY SAND,
fine-grained with medium sand grains, medium
reddish brown, moist, stiff; rootlets; small amounts
of debris.
SANTIAGO FORMATION (Tsa): SILTY
SANDSTONE, fine-grained, light orangish brown,
slightly moist, highly weathered, soft.
GRANITIC BEDROCK (Kgr): GRANITE,
medium crystalline, medium orangish brown,
slightly moist, highly weathered, moderately hard;
friable; boulders at upper contact.
TOTAL DEPTH 7.5 FT.
NO WATER, NO CAVING
TP-4 0.0-4.0 SC
4.0-7.5
ALLUVIUM (Pal): CLAYEY SAND, fine-
grained with some medium to coarse sand and
gravel, medium grayish brown, wet, stiff; rootlets;
roots.
@ 1.5 ft. light orangish brown, moist.
GRANITIC BEDROCK (Kgr): GRANITE, fine
to medium crystalline, light gray with orange
oxidation, slightly moist, highly weathered,
moderately hard; friable.
TOTAL DEPTH 7.5 FT.
NO WATER, NO CAVING
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
TABLE I continued
LOG OF TEST PITS
Test
Pit No.Depth (ft.) USCS Description
TP-5 0.0-2.0 SM
2.0-5.0 sc
5.0-9.5
ARTIFICIAL FILL - UNDOCUMENTED
(afu): SILTY SAND, fine-grained, light tan gray,
moist, loose.
@ 0.5 ft. fine-grained with medium to coarse sand
grains and gravel, light bluish gray mottled with
red, orange and dark reddish brown, moist,
moderately hard.
ALLUVIUM (Pal): CLAYEY SAND, fine-
grained with medium to coarse sand, gravel and
cobbles, medium reddish brown, slightly moist,
very stiff; calcium carbonate.
SANTIAGO FORMATION (Tsa): SANDY
SILTSTONE, fine-grained with some medium to
coarse sand, slightly moist, moderately weathered,
moderately hard.
TOTAL DEPTH 9.5 FT.
NO WATER, NO CAVING
TP-6 0.0-1.5 SC
1.5-3.0
3.0-8.0
SC
ARTIFICIAL FILL - UNDOCUMENTED
(afu): CLAYEY SAND, light bluish gray mottled
with red, orange and dark brown, slightly moist,
stiff; medium to coarse sand grains with gravel;
rootlets; 1" layer of asphalt at base.
ALLUVIUM (Pa»: CLAYEY SAND, fine-
grained with, medium to coarse sand grains and
gravel, dark brown, slightly moist, stiff.
SANTIAGO FORMATION (Tsa): SILTY
SANDSTONE, fine-grained with medium to
coarse sand grains and gravel, slightly moist,
moderately weathered, moderately hard; orange
oxidized zone in east wall of trench; some micro-
shearing.
TOTAL DEPTH 8.0 FT.
NO WATER, NO CAVING
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
TABLE I continued
LOG OF TEST PITS
Test
Pit No.Depth (ft.) USCS Description
TP-7 0.0-10.0 SM
10.0-12.0 SC
12.0-13.5
ARTIFICIAL FILL - UNDOCUMENTED
(afu): SILTY SAND, fine-grained, light tan gray,
moist, loose.
@ 8.5 ft. medium brown.
ALLUVIUM (Qal): CLAYEY SAND, fine-
grained with medium to coarse sand and gravel,
medium brown mottled with red and orange,
slightly moist, stiff.
SANTIAGO FORMATION (Tsa): SILTY
SANDSTONE, fine-grained with medium to
coarse sand grains and gravel, light olive gray
with orange oxidation, moist, moderately hard;
highly weathered; calcium carbonate.
TOTAL DEPTH 13.5 FT.
NO WATER, NO CAVING
TP-8 0.0-8.0 SM
8.0-13.5 SM
sc
ARTIFICIAL FILL - UNDOCUMENTED
(afu): SILTY SAND, fine-grained, light tan gray,
moist, loose.
@ 3.0 ft. -1.0 ft. x 1.0 ft. concrete fragments and
wood debris.
6" x 6" quartz cobble; some orange oxidation at
depth.
ALLUVIUM (Qal): SILTY SAND, fine-grained,
light brownish gray, dry, moderately dense;
friable; rootlets and wood debris; old soil horizon.
@ 9.0 ft. CLAYEY SAND, fine-grained with
medium to coarse sand grains and gravel, slightly
moist, very stiff; rootlets, calcium carbonate.
TOTAL DEPTH 13.5 FT.
NO WATER, NO CAVING
PACIFIC SOILS ENGINEERING, INC.
APPENDIX C
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
DESCRIPTION OF LABORATORY ANALYSIS
Direct Shear Tests
Direct shear tests were performed on samples that were remolded to 90 percent of the laboratory
maximum density. Samples were tested after inundation and confinement for twenty-four (24)
hours. Tests were made under various normal loads at a constant rate of strain of 0.05 inches
per minute. Shear test data are presented in Table II and on Plates C-l and C-2.
Expansion tests
Expansion tests were performed on selected samples in accordance with the expansion index
UBC Standard No. 18-2. Results are presented in Table II.
Consolidation Tests
Consolidation characteristics were determined for "undisturbed" samples considered
representative of the subsurface materials encountered. Samples were laterally restrained and
axially loaded in successively doubled increments from approximately 1/8 tons per square foot
(tsf) to approximately 2 tsf. Each load was maintained for approximately twenty-four (24)
hours, after which loading was continued. In order to determine rebound characteristics, final
loads were decreased to approximately 1/4 tsf. Results of this test are presented on Plates C-3.
Compaction Characteristics
Maximum densities and optimum moistures were determined for selected samples in
accordance with ASTM:D 1557-91. Results are presented in Table II.
Hydrometer Analyses
Hydrometer grain-size analyses were performed on the minus No. 10 sieve portion of selected
samples. These tests were used as an aid in soil classification. The results of these tests are
shown in Table II.
Moisture/Density
Moisture/density testing was conducted on "undisturbed" ring samples obtained from the
borings. Results of this testing are presented on the Log of Borings, Plates B-l through B-5
(Appendix B).
Chemical/Resistivity
Chemical/resistivity testing was conducted by Del Mar Analytical and is presented on Plates
C-4 through C-l5.
PACIFIC SOILS ENGINEERING, INC.
TABLE II
SUMMARY OF LABORATORY TEST DATA
W.O. 401036
BORING
HS-01
HS-01
HS-02
HS-02
HS-04
HS-04
TP-1
TP-1
DEPTH
(FEET)
5
15
5
10
7.5
10
5
8
SOIL DESCRIPTION
SILTY SAND
SANDSTONE (Tsa)
SANDY CLAY
SILTY SAND
SANDY CLAY
SANDY CLAY
SILTY SAND
SANDY CLAY
GROUP
SYMBOL
SM
CL
SM
CL
CL
SM
CL
MAXIMUM
DENSITY
(PCF)
122.3
130.2
OPTIMUM
MOISTURE
CONTENT
(%)
11.4
10.0
IN-SITU
DRY
DENSITY
(PCF)
108.3
114.4
113.5
111.7
107.5
IN-SITU
MOISTURE
CONTENT
(%)
9.4
15.7
11.2
16.1
10.8
DEGREE
OF
SATURATION
C/.|
47
93
65
89
53
PLUS
NO.4
SIEVE
(%)
0
1
0
4
0
0
15
0
COARSE
SAND
(%)
0
1
1
4
2
1
6
1
MEDIUM
TO FINE
SAND
(%)
70
50
32
38
66
41
52
34
SILT
(0.075mm - 0.005mm)
(%)
17
22
25
20
19
19
16
23
CLAY
(minus 0.005mm)
(%)
13
26
42
34
13
39
11
42
EXPANSION
INDEX
UBC 18-2
72
25
COHESION
(PSF)
200
500
FRICTION
ANGLE
(DEGREES)
36
25
OTHER TESTS
REMARKS
CONSOL
CHEM
USHR
USHR
CHEM
Pacific Soils Engineering, Inc.
4,000
3,800
3,600
3,400
3,200
3,000
2,800
CM 2<600
ri 2,400.g
oo 2,200
HI
£ 2,000
</>
K 1,800
1'600
1,400
1,200
1,000
800
600
400
200
0
UJ
DIRECT SHEAR TEST
Undisturbed
f
500 1,000 1,500 2,000 2,500 3,000
NORMAL STRESS Ibs./ft 2
3,500 4,000
boring
HS-02
depth (ft.)
10.0
density (pcf)
112
in situ
moist. (%)
16.1
-200
sieve (%)
54
group
symbol
SM
typical names
SILTY SAND
COHESION 200 psf.
FRICTION ANGLE 36.0 degrees
DIRECT SHEAR TEST
PACIFIC SOILS
ENGINEERING, INC.
W.O. 401036 PLATE C-1
CNJ
t:
wi.Q
CO
COLU
OH\-co
OH
LU
I
CO
4,000
3,800
3,600
3,400
3,200
3,000
2,800
2,600
2,400
2,200
2,000
1,800
1,600
1,400
1,200
1,000
800
600
400
200
0
DIRECT SHEAR TEST
Undisturbed
500 1,000 1,500 2,000 2,500 3,000 3,500 4,000
NORMAL STRESS Ibs./ft
boring
HS-04
depth (ft.)
7.5
dry
density (pcf)
108
in situ
moist. (%)
10.8
-200
sieve (%)
32
group
symbol
CL
typical names
SANDY CLAY
COHESION 500 psf.
FRICTION ANGLE 25.0 degrees
DIRECT SHEAR TEST
PACIFIC SOILS
ENGINEERING, INC.
W.O. 401036 PLATE C-2
COMPRESSIVE STRESS IN TSF
0.1 4 567891 4 5678 910
-2.0
-1.0
0.0
I- 1.0
(D
LU
X
LU
O
Z
<
O
H
Z
LU
Ocr
LUQ.
2.0
3.0
4.0
5.0
6.0
7.0
8.0
boring
HS-01
depth (ft.)
15.0
dry
density (pcf)
114
in situ
moist. (%)
15.7
in situ
satur. (%)
93
-200
sieve (%)
48
group
symbol typical names
SANDSTONE (Tsa)
REMARKS: WATER ADDED AT 1.07 TSF
CONSOLIDATION CURVE
PACIFIC SOILS
ENGINEERING, INC.
W.O. 401036 PLATE C-3
Del Mar Analytical
17461Derian Ave., Suite 100, Irvine, CA 92614 (949) 261-1022 FAX (949) 260-3297
1014 E. Cooley Dr., Suite A, Colton, CA 92324 (909) 370-4667 FAX (909) 370-1046
9484 Chesapeake Dr., Suite 805, San Diego, CA 92123 (858) 505-8596 FAX (858) 505-9689
9830 South 51st St., Suite 8-120, Phoenix, AZ 85044 (480) 785-0043 FAX (480) 785-0851
2520 E. Sunset Rd. #3, Las Vegas, NV 89120 (702) 798-3620 FAX 1702] 798-3621
LABORATORY REPORT
Prepared For: Pacific Soils Engineering, Inc.
7715 Convoy Court
San Diego, CA 92111
Attention: Ron Buckley
Project: 401036
Sampled: 05/09/05
Received: 05/26/05
Issued: 06/01/0508:51
NELAP#01108CA California ELAP# 1197 CSDLAC#10117
The results listedwithin this Laboratory Report pertain only to the samples tested in the laboratory. The analyses contained in this report
were performed in accordance with the applicable certifications as noted. All soil samples are reported on a wet weight basis unless
othenvise noted in the report. This Laboratory Report is confidential and is intended for the sole use of Del Mar Analytical and its client.
This report shall not be reproduced, except in full, without written permission from Del Mar Analytical. The Chain of Custody, 1 page, is
included and is an integral part of this report.
This entire report was reviewed and approved for release.
LABORATORY ID
IDE 1767-01
IDE 1767-02
SAMPLE CROSS REFERENCE
CLIENT ID
TP-1@8'
HS-2@5'
MATRIX
Soil
Soil
Reviewed By:
x'"7
Del Mar Analytical, Irvine
Sushmitha Reddy For Lisa Reightley
Project Manager
H)FJ7f,7 <ptt!,ei,,f7>
PL ATE C-4
Del Mar Analytical
Pacific Soils Engineering, Inc.
7715 Convoy Court
San Diego, CA 92111
Attention: Ron Buckley
Project ID: 401036
Report Number: IOE1767
17461 Derian Ave., Suite 100, Irvine, CA 92614 (949) 261-1022 FAX (949) 260-3297
1014 E. Cooley Dr., Suite A, Colton, CA 92324 (909) 370-4667 FAX (909) 370-1046
9484 Chesapeake Dr., Suite 805, San Diego, CA 92123 (8S8) 505-8596 FAX (858) 505-9689
9830 South 51 st St., Suite 8-120, Phoenix, AZ 85044 (480) 785-0043 FAX (480) 785-0851
2S20 E. Sunset Rd. #3, Las Vegas, NV 89120 (702) 798-3620 FAX (702) 798-3621
Sampled: 05/09/05
Received: 05/26/05
Analyte
Sample ID: IOE1767-01 (TP-1@8' - Soil)
Reporting Units: %
Soluble Sulfate
Sample ID: IOE1767-01 (TP-1@8' - Soil)
Reporting Units: mg/kg
Alkalinity as CaCO3
Chloride
Sample ID: IOE1767-01 (TP-1@8' - Soil)
Reporting Units: ohms/cm
Resistivity
Sample ID: IOE1767-01 (TP-1@8' - Soil)
Reporting Units: pH Units
pH
Sample ID: IOE1767-02 (HS-2@5' - Soil)
Reporting Units: %
Soluble Sulfate
Sample ID: IOE1767-02 (HS-2@5' - Soil)
Reporting Units: mg/kg
Alkalinity as CaCO3
Chloride
Sample ID: IOE1767-02 (HS-2@5' - Soil)
Reporting Units: ohms/cm
Resistivity
Sample ID: IOE1767-02 (HS-2@5' - Soil)
Reporting Units: pH Units
PH
Method
INORGANICS
Reporting
Batch Limit
EPA 300.0 5E27054 0.00050
SM2320B-MOD 5E26117 100
EPA 300.0 5E27054 5.0
EPA 120.1 MOD. 5E26126 NA
EPA9045C 5E26118 NA
EPA 300.0 5E27054 0.00050
SM2320B-MOD 5E26117 100
EPA 300.0 5E27054 5.0
EPA 120.1 MOD. 5E26126 NA
EPA9045C 5E26118 NA
Sample Dilution Date Date Data
Result Factor Extracted Analyzed Qualifiers
0.0060 1 5/27/2005 5/28/2005
600 1 5/26/2005 5/26/2005 H3
13 1 5/27/2005 5/28/2005
2600 1 5/26/2005 5/26/2005
6.47 1 5/26/2005 5/26/2005 H3
0.0048 1 5/27/2005 5/28/2005
500 1 5/26/2005 5/26/2005 H3
18 1 5/27/2005 5/28/2005
4700 1 5/26/2005 5/26/2005
8.86 1 5/26/2005 5/26/2005 H3
Del Mar Analytical, Irvine
Sushmitha Reddy For Lisa Reightley
Project Manager
IOEI7f,7 <pu»e2t>f7>
PL ATE C-5
Del Mar Analytical
Pacific Soils Engineering, Inc.
7715 Convoy Court
San Diego, CA 92111
Attention: Ron Buckley
Project ID: 401036
Report Number: IOE1767
17461 Derian Ave., Suite 100, Itvine, CA 92614 (949) 261 -1022 FAX (949) 260-3297
1014 E. Cooley Dr., Suite A, Colton, CA 92324 (909) 370-4667 FAX (909) 370-1046
9484 Chesapeake Dr., Suite 805, San Diego, CA 92123 (858) 505-8596 FAX (858) 505-9689
9830 South 51st St., Suite B-120, Phoenix, AZ 85044 (480) 785-0043 FAX (480) 785-08S1
2520 E. Sunset Rd. #3, Las Vegas, NV 89120 (702) 798-3620 FAX (702) 798-3621
Sampled: 05/09/05
Received: 05/26/05
SHORT HOLD TIME DETAIL REPORT
Sample ID: TP-1@8' (IOE1767-01) - Soil
EPA 9045C
Sample ID: HS-2@5' (IOE1767-02) - Soil
EPA 9045C
Hold Time
(in days)
1
Date/Time
Sampled
05/09/2005 17:00
05/09/2005 17:00
Date/Time
Received
05/26/2005 16:45
05/26/2005 16:45
Date/Time
Extracted
05/26/2005 19:25
05/26/2005 19:25
Date/Time
Analyzed
05/26/2005 20:30
05/26/2005 20:30
Del Mar Analytical, Irvine
Sushmitha Reddy For Lisa Reightley
Project Manager
PLATE C-6
Del Mar Analytical
Pacific Soils Engineering, Inc.
7715 Convoy Court
San Diego, CA 92111
Attention: Ron Buckley
Project ID: 401036
Report Number: IOE1767
1 7461Derian Ave., Suite 100, Irvine, CA 92614 (949) 261-1022 FAX (949) 260-3297
1014 E. Cooley Dr., Suite A, Colton, CA 92324 (909) 370-4667 FAX (909) 370-1046
9484 Chesapeake Dr., Suite 805, San Diego, CA 92123 (858) 505-8596 FAX (858) 505-9689
9830 South 51st St., Suite B-120, Phoenix, AZ 85044 (480) 78S-0043 FAX (480I 785-0851
2520 E. Sunset Rd. #3, Las Vegas, NV 891 20 (702) 793-3620 FAX (702) 798-3621
Sampled: 05/09/05
Received: 05/26/05
METHOD BLANK/QC DATA
INORGANICS
Analyte Result
Batch: 5E26117 Extracted: 05/26/05
Duplicate Analyzed: 05/26/2005 (5E26117-DUP1)
Alkalinity as CaC03 2000
Reference Analyzed: 05/26/2005 (5E26117-SRM1)
Alkalinity as CaC03 248
Batch: 5E26118 Extracted: 05/26/05
Duplicate Analyzed: 05/26/2005 (5E26118-DUP1)
pH , 8.81
Batch: 5E26126 Extracted: 05/26/05
Duplicate Analyzed: 05/26/2005 (5E26126-DUP1)
Resistivity 4970
Batch: 5E27054 Extracted: 05/27/05
Blank Analyzed: 05/27/2005 (5E27054-BLK1)
Chloride ND
Soluble Sulfate ND
LCS Analyzed: 05/27/2005 (5E27054-BS1)
Chloride 49.3
Soluble Sulfate 0.0101
Reporting Spike Source %REC RPD Data
Limit Units Level Result %REC Limits RPD Limit Qualifiers
100
NA
NA
mg/kg
pH Units
ohms/cm
Source: IOE1552-01
2100
4.0 mg/kg 258 96 94-105
Source: IOE1767-02
8.86
Source: IOE1767-02
4700
5.0
0.00050
5.0
0.00050
mg/kg
%
mg/kg 50.0
% 0.0100
99 90-110
101 90-110
20
20
Del Mar Analytical, Irvine
Sushmitha Reddy For Lisa Reightley
Project Manager
10EI7(,7
PLATEC-7
Del Mar Analytical
Pacific Soils Engineering, Inc.
7715 Convoy Court'
San Diego, CA 92111
Attention: Ron Buckley
Project ID: 401036
Report Number: IOE1767
17461Derian Ave., Suite 100, Itvine, CA 92614 (949) 261-1022 FAX (949) 260-3297
1014 E. Cooley Dr., Suite A, Colton, CA 92324 (909) 370-4667 FAX (909) 370-1046
9484 Chesapeake Dr., Suite 805, San Diego, CA 92123 (858) 505-8596 FAX (858) 505-9689
9830 South 51st St., Suite B-120, Phoenix, AZ 85044 (480) 785-0043 FAX (480) 785-0851
2520 E. Sunset Rd. #3, Las Vegas, NV 89120 (702) 798-3620 FAX (702) 798-3621
Sampled: 05/09/05
Received: 05/26/05
METHOD BLANK/QC DATA
Analyte
Batch: 5E27054 Extracted: 05/27/05
Result
INORGANICS
Reporting
Limit Units
Matrix Spike Analyzed: 05/27/2005 (5E27054-MS1)
Chloride 68.4 5.0 mg/kg
Soluble Sulfate 0.0109 0.00050 %
Matrix Spike Dup Analyzed: 05/27/2005 (5E27054-MSD1)
Chloride 66.6 5.0 mg/kg
Soluble Sulfate 0.0108 0.00050 %
Spike Source %REC RPD Data
Level Result %REC Limits RPD Limit Qualifiers
Source: IOE1816-01
50.0 19 99 80-120
0.0100 0.00082 101 80-120
Source: IOE1816-01
50.0 19 95 80-120 3 20
0.0100 0.00082 100 80-120 1 20
Del Mar Analytical, Irvine
Sushmitha Reddy For Lisa Reightley
Project Manager
IOEI767 <PUge f nf 7>
PLATE C-8
Del Mar Analytical
Pacific Soils Engineering, Inc.
7715 Convoy Court
San Diego, CA 92111
Attention: Ron Buckley
Project ID: 401036
Report Number: IOE1767
17461 Derian Ave., Suite 100, Irvine, CA 92614 (949)261-1022 FAX (949) 260-3297
1014 E. Cooley Df., Suite A, Colton, CA 92324 (909) 370-4667 FAX (909) 370-1046
9484 Chesapeake Dr., Suite 805, San Diego. CA 92123 (858) 505-8S96 FAX (858) 505-9689
9830 South 51st St., Suite B-l 20, Phoenix, AZ 85044 (480) 785-0043 FAX (480) 785-0851
2520 E. Sunset Rd. #3, Las Vegas, NV 89120 (702) 798-3620 FAX (702) 798-3621
Sampled: 05/09/05
Received: 05/26/05
DATA QUALIFIERS AND DEFINITIONS
H3 Sample was received and analyzed past holding time.
ND Analyte NOT DETECTED at or above the reporting limit or MDL, if MDL is specified.
RPD Relative Percent Difference
Del Mar Analytical, Irvine
Sushmitha Reddy For Lisa Reightley
Project Manager
PL ATE C-9
Del Mar Analytical
Pacific Soils Engineering, Inc.
7715 Convoy Court
San Diego, CA 92 111
Attention: Ron Buckley
Project ID: 401036
Report Number: IOE1767
17461 Derian Ave., Suite 100, In/ine, CA 92614 (949) 261-1022 FAX (949) 260-3297
1014 E. Cooley Dr., Suite A, Colton, CA 92324 (909) 370-4667 FAX (909) 370-1046
9484 Chesapeake Dr., Suite 805, San Diego, CA 92123 (858) 505-8596 FAX (858) 505-9689
9830 South 51st St., Suite B-120, Phoenix, AZ 85044 (480) 785-0043 FAX (480) 785-0851
2520 E. Sunset Rd. #3, Las Vegas, NV 89120 (702) 798-3620 FAX (702) 798-3621
Sampled: 05/09/05
Received: 05/26/05
DATA QUALIFIERS AND DEFINITIONS
H3 Sample was received and analyzed past holding time.
ND Analyte NOT DETECTED at or above the reporting limit or MDL, if MDL is specified.
RPD Relative Percent Difference
Del Mar Analytical, Irvine
Sushmitha Reddy For Lisa Reightley
Project Manager
PLATE C-10
Del Mar Analytical
Pacific Soils Engineering, Inc.
7715 Convoy Court
San Diego, CA 92111
Attention: Ron Buckley
Project ID: 401036
Report Number: 1OE1767
1 7461 Derian Ave., Suite 100, Irvine, CA 92614 (949) 261 -1022 FAX (949) 260-3297
1014 E. Cooley Df., Suite A, Colton, CA 92324 (909) 370-4667 FAX (909) 370-1046
9484 Chesapeake Dr., Suite 805, San Diego, CA 92123 (858) 505-8596 FAX (858) 505-9689
9830 South 51 st St., Suite B-l 20, Phoenix, AZ 85044 (480) 785-0043 FAX (480) 785-0851
2 520 E. Sunset Rd #3, Las Vegas, NV 89120 1702) 798-3620 FAX (702) 798-3621
Sampled: 05/09/05
Received: 05/26/05
Certification Summary
Del Mar Analytical, Irvine
Method
EPA 120.1 MOD.
EPA 300.0
EPA 9045C
SM2320B-MOD
Matrix
Soil
Soil
Solid
Solid
Nelac California
N/A N/A
X X
X . X
N/A N/A
Nevada and NELAP provide analyte specific accreditations. Anafyte specific information for Del Mar Analytical may be obtained by
contacting the laboratory or visiting our website at www.dmalabs.com.
Del Mar Analytical, Irvine
Sushmitha Reddy For Lisa Reightley
Project Manager
PL ATE C-11
APPENDIX D
PACIFIC SOILS ENGINEERING, INC.
80
La Costa / 25' fill slope 2 :1 / W.O. 401036
Z:\1000\401036\25AFC.PL2 Run By: Doug Ayers 5/31/2005 3:38PM
Soil Soil Total Saturated Cohesion Friction Piez.
Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface
No. (pcf) (pcf) (psf) (deg) No.
afc 1 130.0 130.0 150.0 29.0 0
60
40
20 •
20 40 60
i
80 100
GSTABL7V.2 FSmin=1.79
Safety Factors Are Calculated By The Modified Bishop Method
PLATE D-1
80
La Costa / 25' fill slope 2 :1 / W.O. 401036/ Pseudostatic
Z:\1000\401036\25AFC.PL2 Run By: Doug Ayers 5/31/2005 4:12PM
Soil Soil Total Saturated Cohesion Friction Piez.
Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface
No. (pcf) (pcf) (psf) (deg) No.
afc 1 130.0 130.0 150.0 29.0 0
Load
Horiz Eqk
Value
0.150g<
60
40
20 •
i ..
20 40 60 80 100
GSTABL7V.2 FSmin=1.31
Safety Factors Are Calculated By The Modified Bishop Method
PLATE D-2
60
La Costa/ 20' Fill Slope & 5' MSB Wall/ W.O. 401036
Z:\1000\401036\WALL.PL2 Run By: Doug Ayers 6/1/2005 8:46AM
Soil
Desc.
afc
wall
Soil Total Saturated Cohesion Friction Piez.
Type Unit Wt. Unit Wt. Intercept Angle Surface
No.
1
2
(pcf)
130.0
200.0
(pcf)
130.0
200.0
(psf)
150.0
0.0
(cleg)
29.0
0.0
No.
0
0
50
40
30
20
10
10
. L-
20 30 40 50 60 70
I
80 90
GSTABL7V.2 FSmin=1.85
Safety Factors Are Calculated By The Modified Bishop Method
PLATE D-3
60 ,
La Costa/ 20' Fill Slope & 51 MSB Wall/ W.O. 401036/ Pseudostatic
Z:\1000\401036\WALL.PL2 Run By: Doug Ayers 6/1/2005 8:53AM
Soil Soil Total Saturated Cohesion Friction Piez.
Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface
No. (pcf) (pcf) (psf) (deg) No.
afc 1 130.0 130.0 150.0 29.0 0
wall 2 200.0 200.0 0.0 0.0 0
Load
Horiz Eqk
Value
0.150g<
50
40
30
20
10 i
10 20 30 40
__. L „
50
I....
60
. I
70 80 90
GSTABL7V.2 FSmin=1.35
Safety Factors Are Calculated By The Modified Bishop Method
PLATE D-4
SURFICIAL SLOPE STABILITY
FILL SLOPE
SLOPE SURFACE
-----\---—) a
FLOW LINES
Assume: (1) Saturation To Slope Surface
(2) Sufficient Permeability To Establish Water Flow
Pw = Water Pressure Head=(z)(cosA2(a))
Ws = Saturated Soil Unit Weight
Ww = Unit Weight of Water (62.4 Ib/cu.ft.)
u = Pore Water Pressure=(Ww)(z)(cosA2(a))
z = Layer Thickness
a = Angle of Slope Slope ratio: 2H : IV
phi = Angle of Friction
c = Cohesion
Fd = (0.5)(z)(Ws)(sin(2a))
Fr = (z)(Ws-Ww)(cosA2(a))(tan(phi)) + c
Factor of Safety (FS) = Fr/Fd
Given:
Calculations:
Ws
(pcf)
130
z
(ft)
•->j
a
(degrees)
26.6
(radians)
0.46365
phi
(degrees)
29
(radians)
0.50615
c
(psf)
150
Pw
2.40
u
149.76
Fd
156.00
Fr
239.93
FS
1.54
SURFSTAB fill
PLATE D-5
PACIFIC SOILS ENG.
APPENDIX E
PACIFIC SOILS ENGINEERING, INC.
PACIFIC SOILS ENGINEERING, INC.
*
EARTHWORK SPECIFICATIONS
These specifications present generally accepted standards and minimum earthwork requirements
for the development of the project. These specifications shall be the project guidelines for
"'rt
earthwork except where specifically superceded in preliminary geology and soils reports, grading
plan review reports or by prevailing grading codes or ordinances of the controlling agency.
I. GENERAL
A. The contractor shall be responsible for the satisfactory completion of all
earthworks in accordance with the project plans and specifications.
B. The project Soil Engineering Geologist or their representatives shall provide
testing services, and geotechnical consultation during the duration of the project.
C. All clearing, grubbing, stripping and site preparation for the project shall be
accomplished by the Contractor to the satisfaction of the Soil Engineer.
D. It is the Contractor's responsibility to prepare the ground surface to receive the
fills to the satisfaction of the Soil Engineer and to place, spread, mix and compact
the fill in accordance with the job specifications and as required by the Soil
Engineer. The Contractor shall also remove all material considered by the Soil
Engineer to be unsuitable for use in the construction of compacted fill.
E. The Contractor shall have suitable and sufficient equipment in operation to handle
the amount of fill being placed. When necessary, equipment will be shut down
temporarily in order to permit proper compaction of fills.
II. SITE PREPARATION
A. Excessive vegetation and all deleterious material shall be disposed of offsite as
required by the Soil Engineer. Existing fill, soil, alluvium or rock materials
determined by the Soil Engineer as being unsuitable for placement in compacted
fills shall be removed and wasted from the site. Where applicable, the Contractor
may obtain the approval of the Soil Engineer and the controlling authorities for
the project to dispose of the above described materials, or a portion thereof, in
designated areas onsite.
After removals as described above have been accomplished, earth materials
deemed unsuitable in their natural, in-place condition, shall be removed as
recommended by the Soil Engineer/Engineering Geologist.
Earthwork Specifications
Page 2
B. After the removals are as delineated in Item II, A, above, the exposed surfaces
shall be disced or bladed by the Contractor to the satisfaction of the Soil Engineer.
The prepared ground surfaces shall then be brought to the specified moisture'
condition, mixed as required, and compacted ad tested as specified. In areas
where it is necessary to obtain the approval of the controlling agency, prior to
placing fill, it will be the contractor's responsibility to notify the proper
, authorities.
C. Any underground structures such as cesspolls, cisterns, mining shafts, tunnels,
septic tanks, wells, pipelines or others not located prior to grading are to be
removed or treated in a manner prescribed by the Soil Engineer and/qr the
controlling agency for the project.
III. COMPACTED FILLS
A. Any materials imported or excavated on the property may be utilized in the fill,
provided each material has been determined to be suitable by the Soil Engineer.
Deleterious material no disposed of during clearing or demolition shall be
removed from the fill as directed by the Soil Engineer.
B. Rock or rock fragments less than eight inches in the largest dimension may be
utilized in the fill, provided they are not placed in concentrated pockets and the
distribution of the rocks is approved by the Soil Engineer.
C. Rocks greater than eight inches in the largest dimension shall be taken offsite, or
placed in accordance with the recommendations of the Soils Engineer in areas
designated as suitable for rock disposal.
D. All fills, including onsite and import materials to be used for fill, shall be tested in
the laboratory by the Soil Engineer. Proposed import materials shall be approved
prior to importation.
E. The fill materials shall be placed by the Contractor in layers that when compacted
shall not exceed six inches. Each layer shall be spread evenly and shall be
thoroughly mixed during the spreading to obtain a near uniform moisture
condition and a uniform blend of materials.
All compaction shall be achieved at optimum moisture content, or above, as
determined by the applicable laboratory standard. No upper limit on the moisture
content is necessary; however, the Contractor must achieve the necessary
compaction and will be alerted when the material is too wet and compaction
cannot be attained.
MV/Eaiihwork Spccifications (new)
Earthwork Specification?
Page3
F. Where the moisture content of the fill material is below the limit specified by the
Soil Engineer, water shall be added and the materials shall be blended until
uniform moisture content, within specified limits, is achieved. Where the
moisture content of the fill material is above the limits specified by the Soil
Engineer, the fill materials shall be aerated by discing, blading or other
satisfactory method until the moisture content is within the limits specified.
G. Each fill layer shall be compacted to minimum project standards, in compliance
with the testing methods specified by the controlling governmental agency and in
accordance with recommendations of the Soil Engineer.
In the absence of specific recommendations by the Soil Engineer to the contrary,
the compaction standard shall be ASTM:D 1557-91.
H. Where a slope receiving fill exceeds a ratio of five-horizontal to on-vertical, the
fill shall be keyed and benched through all unsuitable topsoil, colluvium,
alluvium, or creep material, into sound bedrock or firm material, in accordance
with the recommendations and approval of the Soil Engineer.
I. Side hill fills shall have a minimum key width of 15 feet into bedrock or firm
materials, unless otherwise specified in the soil report and approved by the Soil
Engineer in the field.
J. Drainage terraces and subdrainage devices shall be constructed in compliance
with the ordinances of the controlling governmental agency and/or with the
recommendations of the Soil Engineer and Engineering Geologist.
K. The Contractor shall be required to maintain the specified minimum relative
compaction out to the finish slope face of fill slopes, buttresses, and stabilization
fills as directed by the Soil Engineer and/or the governing agency for the project.
This may be achieved by either overbuilding the slope and cutting back to the
compacted core, or by direct compaction of the slope face with suitable
equipment, or by any other compaction of the slope face with suitable equipment,
or by any other procedure, which produces the designated result.
L. Fill-over-cut slopes shall be properly keyed through topsoil, colluvium or creep
material into rock or firm material; and the transition shall be stripped of all soil
or unsuitable materials prior to placing fill.
The cut portion should be made and evaluated by the Engineering Geologist prior
to placement of fill above.
M. Pad areas in natural ground and cut shall be approved by the Soil Engineer.
Finished surface of these pads may be requiring scarification and recompaction.
MV/Earthwork Specifications (new)
Earthwork Specifications
Page 4
IV. CUT SLOPE
A. The Engineering Geologist shall inspect all cut slopes and shall be notified by the
Contractor when cut slopes are started.
B. If, during the course of grading, unforeseen adverse or potentially adverse
geologic conditions are encountered, the Engineering Geologist and Soil Engineer
shall investigate, analyze and make recommendations to treat these problems.
C. Non-erodible interceptor swales shall be placed at the top of cut slopes that face
the same direction as the prevailing drainage.
D. Unless otherwise specified in soil and geological reports, no cut slopes shall be
excavated higher or steeper than that allowed by the ordinances of controlling
governmental agencies.
E. Drainage terraces shall be constructed in compliance with the ordinances of the
controlling governmental agencies, an/or in accordance with the
recommendations of the Soil Engineer or Engineering Geologist.
V. GRADING CONTROL
A. Fill placement shall be observed by the Soil Engineer an/or his representative
during the progress of grading.
Field density tests shall be made by the Soil Engineer or his representative to
evaluate the compaction and moisture compliance of layer of fill. Density tests
shall be performed at intervals no to exceed two feet of fill height. Where
sheepsfoot rollers are used, the soil may be disturbed to a depth of several inches.
Density determinations shall be taken in the compacted material below the
disturbed surface at a depth determined by the Soil Engineer or his representative.
B. Where tests indicate that the density of any layer of fill, or portion thereof, is
below the required relative compaction, or improper moisture is in evidence, the
particular layer or portion shall be reworked until the required density and/or
moisture content has been attained. No additional fill shall be placed over an area
until the last placed lift of fill has been tested and found to meet the density and
moisture requirements and that lift approved by the Soil Engineer.
C. Where the work in interrupted by heavy rains, fill operations shall not be resumed
until the field observations and tests by the Soil Engineer indicate the moisture
content and density of the fill are within the limits previously specified.
MV/E;mhwork Specifications (new)
Earthwork Specifications
Page 5
D. During construction, the Contractor shall properly grade all surfaces to maintain
good drainage and prevent ponding of water. The Contractor shall take remedial
measures to control surface water and to prevent erosion of graded area until such
time as permanent drainage and erosion control measures have been installed.
E. Observation and testing by the Soil Engineer shall be conducted during the filling
and compacting operations in order that he will be able to state in his opinion all
cut and filled areas are graded in accordance with a approved specifications.
F. After completion of grading and after the Soil Engineer and Engineering
Geologist have finished their observations of the work, final reports shall be
submitted. No further excavation or filling shall be undertaken without prior
notification of the Soil Engineer and/or Engineering Geologist.
IV. SLOPE PROTECTION
All finished cut and fill slopes shall be planted an/or protected from erosion in
accordance with the project specifications an/or as recommended by a landscape
architect.
MV/Earth\vork Specifications (new)
CANYON SUBDRAIN DETAIL
TYPE A
COMPACTED TILL
COLLUVIUM AND ALLUVIUM (REMOVE)
—»—BEDROCK
TYPICAL BENCHING
"P8^
-SEE DETAIL ALTERNATE "A"(PLATE C-Z )
NOTE FINAL ^o' OF PIPE AT OUTLET SHALL BE NON-PERFORATED
TYPE B
PROPOSED COMPACTED FILL
•NATURAL GROUND
COLLUVIUM AND ALLUVIUM (REMOVE)
TYPICAL BENCHING
BEDROCK
SEE DETAIL ALTERNATE "B (PLATE G-2 )
NOTE:FINAL 20 OF PIPE AT OUTLET SHALL BE NON-PERFORATED
PLATE C'l
PACIFIC SOILS ENGINEERING, INC.
W. O. DATE
CANYON SUBDRAIN ALTERNATE DETAILS
ALTERNATE I
PIPE AND FILTER MATERIAL
FILTER UATCRlAL:UIN.VOL.OF9FT3/LIN.rT.
12 IN.HIN
€ IN UIN.
6 IN. f ABS OR PVC PIPE OR APPROVED
SUBSTITUTE WITH UIN. B PERF. ,1/4 IN. ft
PER LINEAL FOOT IN BOT TOU HALF Of
PIPE. "*'
A~l ASTUD27SI, SDR350R ASTu DJ034, SDR 35 OR B~l
AST_U DIS^7, SCHD.4O ASTU DireS, SCH0.40
FOR CONTINUOUS RUN IN EXCESS OF5OO FEET USE 6 IN. 0 PIPE
IN.UIN
$
6 IN. UIN.
^\
A-2
ALTERNATE Z
FILTER MATERIAL WRAPPED IN FABRIC
I IN. MAX. GRAVEL WRAPPED IN FILTER FABRIC
I IH. HAX.GRAVCL OP APPROVED EQUIVALENT 9 FT. /FT
UIRAFI HO FILTER FABRIC OR APPROVED EQUIVALENT
(TYPICAL)
6 IN.UIN.
/ OVERLAP
PROPOSED FINISHED GRADE
DETAIL OF CANYON
SUBDRAIN TERMINAL
FOR ALTERNATES
A2 AND B2'
NATIVE BACKFILL
UlRAFl I4O FILTER FABRIC OR
APPROVED EQUIVALENT
I IN. MAX. OPEN GRADED
GRAVEL OR APPROVED
EQUIVALENT
NON-PERF PCRF.6IN.
6IN.fHIN ffHIN.PIPE
6 IN. UIN.
OVERLAP
ALTERNATE 3
PERFORATED PIPE SURROUNDED
Wl TH FILTE R MA TERIA L
6 IN. UIN. COVER
4 IN MIN.BEDDING
6 IN. MIN.
OVERLAP
FILTER MATERIAL 9 FT./FT
A'3 PERFORATED PIPE 6 IN. f UIN.
4 IN. UIN.
BEDDING
B-3
FILTER MATERIAL
SIEVE SIZE PERCENT PASSING
UN.
3/4 IN.s/e IN.
NO. 4No.e
NO. SO
NO. SO
NO. SOO
100
90-IOO
25-4O
IS -33
S-IS
0-7
0-3
PLATE G-2
PACIFIC SOILS ENGINEERING INC.
W.O. DATE
Alternative
No. 2
Typical 2ft.X2ft. gravel filled trench with 4in. diameter
ABS or PVC pipe or approved substitute. Provide min-
imum 8 perforations (i/4"dia.) per lineal foot in bottom
half of pipe. Pipe 1$ to extend full length of butt rest or
stabilization fill with a min.4% gradient to outlet pipes.
15
Alternative
No. 1
Iblanket fill-as required by soil
eng. or geologist (3'min.)
bockcut benched at contact
4'non-perforated pipe to-be placed of lot
lines or as designated by the soil engineer
or geologist
2' mta. hey depth
NOTES:
I. ABS-ASTM 0 27SI, SDR 35 or ASTM 0/527 Sched.40
PVC-ASTM D 3O34t SDR35 or ASTM 01765 Sched.4O
2. Outlets to be provided every 100 ft. and joined to pert,bockdroln pipe by L or Ts. Min. 2% gradient.
3. Gravel trench to be filled with 3/t" pea grovel or approved
substitute.
4. The necessity for upper stages ofbocledrains shall be deter-mined In the field by the soil engineer or geologist. Upperstage outlets should be emptied onto paved terrace aroint
3* mln. key depth
STABILIZATION/BUTTRESS FILL DETAIL
P^ATEG-3
PACIFIC SOILS ENGINEERING, INC.
W.O. DATE_
Cut Lot
5 min.
Unweothered Bedrock
Overexcovote ond
Recompocl
Cul-Fill Lot (Transition)
Compacted Fill
p 5 min.w//////////////////
s ^-Overexcovole ond
Recompoct
Unweolhered Bedrock
deeper overencovolion may be
required by the soils engineer
in sleep cut-fill transition areas
PACIFIC SOILS ENGINEERING, INC..
W. O. DATE
PLATE G-4
t i i i i * t * . I ti't . i ^^^
1) Where noturol slope grodient is 5:l or less, se^Pote G-6.
Where the noturol slope opproothet or exceeds the detion
slope rotio, tpeclol recommendotiont will be provided by
the toil engineer.
2) The need for ond disposiiton of droint will be determined
by the toil engineer bos«d upon eipoted condilioni
Provide o 1:1 minimum
projection from design
toe of slope to toe
of key.
Noturd slope to be
restored with
compocted fill
Bockcut varies
Compocted fill
Mointoin min. 15'width horiz
from foce of slope to
bench/bo cfccut.
&&f/rz"-L- ^S.TPZ'min. I
in bedrock U—,|5'min.—
or opproved.l mjp j^gy depih 2fx3'
—SIDE HILL FILL DETAIL
Noturoi Slopes 5?l or Steeper
PLATE G-5
PACIFIC SOILS ENGINEERING, INC.
W.O DATE
i i i i
Detoil for Rll Slope Toeing Out on Plot Alluvioted Conyon
Oriqlnol ground turfoce
Too of dope ot thown on grodlng plon.
riqinol ground Surface to be restored with compacted fill.
Comoocted fill
BocVcut vones. For deep
remove!», bocVcut should be
mode no steepv ihon 1:1 or m
for sofety considerotioni
. /X S
-SiV/
Antltipoled olluvlol
depth per toil engineer.
Provide o 1:1 min. projection from tot of tlopt o« *>own on eroding plon »o the
rtcommtndtd rtmovcl deplh. Slope heigM, «lt« conditions, ond/or locol conditions
could dlctoie fioiter projection*.
Plate G-6
PACIFIC SOILS ENGINEERING. INC
W.O. DATE :
Selective Grading Detail for Stabilization Fill
Unstable Material Exposed in Portion of Cut Slope
Unweothered Bedrock
or approved material
Compacted Fill
"f \/-L
T— I'tilted back (min.)
If recommended by the soils engineer/geologist, the remainingcut port ion of the slope may require removal and replacement
with compacted fill (See Plate C~3)
NOTE-
I. Subdrains are not required unless specified.
2. "w" shall be equipment width (15') for slope heights less than 25 feet. For
slopes greater than 25feet "w"shall be determined by Ihe project soils
engineer/geologist. At no time shall "w" be less than H/2.
PLATE G-7
PACIFIC SOILS ENGINEERING, INC.
W.O DATE
; . t i i i » * 4
Skh Fill Oh Natural Ground
//ha/
original
f5 '/7?/n (a 6e morn famed
frvm slope, face To
min. key dimensions-f5*2'*3
d J disposition of c/nins
determined testd on /ic/d conditions,
ff required, see dtfatf Pfofe G-J.
PLATE G-8
» * *
REMOVAL ADJACENT TO EXISTING FILL
ADJOINING CANYON FILL
Proposed additional compacted fill-
Compacted fill limits line
Oaf
(existing compacted fill) \
\
Temp, compacted fill for drainage only
Oof (to be removed)
placing additional compacted fill
LEGEND
Oaf Artificial fill
Oof Alluvium
CROSS-SECTION B-B'
(Typ. up-conyon)
Not to scale
PLATEG-9
PACIFIC SOILS ENGINEERING, INC.
W 0. DATE
ROCK DISPOSAL DETAIL
FINISH GRADE
AREA FOR FOUNDATIONS,
UTILITIES AND SWIMMING POOLS.
03
1
10' or os described by report
FINISH SLOPE FACE
WINDROW
(TYPICAL)
NOTE: IF NECESSARY, OVERSIZED MATERIAL SHOULD BE REMOVED
FROM THE 15 FOOT ZONE WITH SPECIAL EOUIPMENTfSUCH
AS A ROCK RAKE PRIOR TO PLACING THE NEXT FILL LIFT.
TYPICAL WINDROW DETAIL (END VIEW)
HORIZONTALLY PLACED
COMPACTED FILL
GRANULAR SOIL FLOODED,
TO FILL VOIDS
NOTE: COMPACTED FILL SHALL BE BROUGHT UP AT A HIGHER ELEVATION ALONG WINDROW
SOGRANULAR SOIL CAN BE FLOODED IN A "TRENCH CONDITION".
PROFILE VIEW
111=111=111 sjif-iiiH ni= nisi i|=|ii=in=-iiisiii=iii=»i|-si/i=iii=iir=f/i=i/i=
PLATE C-IO
PACIFIC SOILS ENGINEERING,INC.
W.O. DATE
4 I
Cut/Fill Contact
I)Shown on 'Grading Han-
2)Shown on 'As Built I.
Maintain mln. 15 fill
section from bockcut
to face of finish slope •
H
Original topography
Cut slope^L
. kty ospth 2 x3
Bedrock or approved
foundation material
The cut portion of the slope should be
excavated and evaluated by the
Engineering Geologist/Soils Engineer
prior to constructing the fin portion.
FILL OVER CUT DETAIL PLATE G-\\
PACIFIC SOILS ENGINEERING, INC.
W.O DATE
SETTLEMENT PLATE DETAIL
2 X 2 X 1/4 STE£L PLATE
• STANDARD 3/4 "PIPE NIPPLE. WELDED TOP AND UNDERSIDE
Of PLATE.
•2/<"0X5'LONG GALVANIZED PIPE, STANDARD PIPE THREADS
TOP AND BOTTOM. EXTENSIONS THREADED BOTH ENDS AND
ADDED IN 5' INCREMENTS.
' 3"g SCHEDULE *0 PVC, ADD IN 5'INCREMENTS WITH CLUE JOINTS.
FINAL GRADE
MAINTAIN 5'CLEARANCE OF HEAVY EQUIPMENT. HAND COMPACT
'VERTICAL INCREMENTS OR ALTERNATIVE SUITABLE TO
AND ACCEPTED BY SOILS ENGINEER.
IAND COMPACT INITIAL 5 (VERTICAL) WITHIN IO HORIZONTAL.
"PLACE AND HAND COMPACT INITIAL ^ OF FILL PRIOR TO
ESTABLISHING INITIAL READING.
/
.
^BOTTOM OF CLEANOUT
^PROVIDE A MIN./'THICKNESS OF SAND/GRAVEL BEDDING.
NOTE
1) LOCATIONS OF SETTLEMENT PLATES SHALL BE CLEARLY MARKED AND READILY VISIBLE
(RED FLAGGED) TO EQUIPMENT OPERATORS.
2) CONTRACTOR SHALL MAINTAIN IO'HORIZONTAL CLEARANCE FOR HEAVY EQUIPMENT WITHIN 5*
(VERTICAL) OF PLATE BASE. FILL WITHIN CLEARANCE AREA SHALL BE HAND COMPACTED TO
PROJECT SPECIFICATIONS OR COMPACTED BY ALTERNATIVE APPROVED SOILS ENGINEER.
3) AFTER 5' (VERTICAL) OF FILL IS IN PLACE, CONTRACTOR SHALL MAINTAIN *>' HORIZONTAL
EQUIPMENT CLEARANCE. FILL IN CLEARANCE AREA SHALL BE HAND COMPACTED (OR
APPROVED ALTERNATIVE) IN VERTICAL INCREMENTS NOT TO EXCEED Z FEET.
4) IH THE EVENT OF DAMAGE TO SETTLEMENT PLATE OR EXTENSION RESULTING FROM
EQUIPMENT OPERATING WITHIN PRESCRIBED CLEARANCE AREA, CONTRACTOR SHALL
IMMEDIATELY NOTIFY SOILS ENGINEER AND SHALL BE RESPONSIBLE FOR RESTORING
THE SETTLEMENT PLATES TO WORKING ORDER.
PLATE G-12
PACIFIC SOILS ENGINEER1NGJNC.
W. O. DA TE
Jl
/t/R
12-
4' min.
4" to 8" diameter plastic
PVC pipe (schedule 40)
Groundsurface
min. diameter rigid
steel pipe with cap
_.-..-'•" Fii soils '-.
Backfilled witfa cenwete
Surface Settlement Monument Detail
PLATE G-13
PACIFIC SOILS ENGINEERING, INC.
7715 CONVOY COURT
SAN DIEGO, CA 92111 (858) 560-1713
W.O.:DATE:
II ii
RELATIVE COMPACTION VS. DEPTH
CANYON WALL LAY BACK
DIFFERENTIAL FILL OVEREXCAVATION
DETAILS '
EXISTING TOPOGRAPHY
PROPOSED GRADE
2:1 LAYBACK
OF CANYON WALL
1. ALL FILL PLACED BELOW 50 FEET OF FINISHED GRADE SHALL BE COMPACTED TO A
MINIMUM OF 93% RELATIVE COMPACTION.
2. CANYON WALLS WITHIN 50 FEET OF FINISHED GRADE SHALL BE LAID BACK TO A
SLOPE RATIO OF 2:1 OR FLATTER.
3. ALL BUILDING PADS SHALL BE OVEREXCAVATED TO A MINIMUM OF 1/3 OF THE
MAXIMUM DEPTH OF FILL BELOW THE BUILDING PAD. OVEREXCAVATION DEPTH
NEED NOT EXCEED 17 FEET.
PACIFIC SOILS ENGINEERING, INC.
VER. 9/98 'Plate G-14
APPENDIX F
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
HOMEOWNERS MAINTENANCE AND IMPROVEMENT CONSIDERATIONS
General
Homeowners must assume a certain degree of responsibility for maintaining conditions around
improvements. Of primary importance are maintaining drainage patterns and minimizing the
soil moisture variation below all improvements. Such design, construction and maintenance
provisions may include:
^ Employing contractors for improvements who design and build in recognition of local
building codes and specific site soils conditions.
> Establishing and maintaining positive drainage away from all foundations, walkways,
driveways, patios and other hardscape improvements.
^ Avoiding the construction of planters adjacent to structural improvements. Alternatively,
planter sides/bottoms can be sealed with an impermeable membrane and drained away
from the improvements via subdrains into approved disposal areas.
> Sealing and maintaining construction/control joints within concrete slabs and walkways
to reduce the potential for moisture infiltration into the subgrade soils.
^ Utilizing landscaping schemes with vegetation that requires minimal watering. Watering
should be done in a uniform manner, as equally as possible on all sides of the foundation,
keeping the soil "moist" but not allowing the soil to become saturated.
^ Maintaining positive drainage away from structures and providing roof gutters on all
structures with downspouts that are designed to carry roof runoff directly into area drains
or discharged well, away from the foundation areas.
> Avoiding the placement of trees closer to the proposed structures than a distance of one-
half (1/2) the mature height of the tree.
> Observation of the soil conditions around the perimeter of the structure during extremely
hot/dry or unusually wet weather conditions so that modifications can be made in
irrigation programs to maintain relatively uniform moisture conditions.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Sulfates
Homeowners should be cautioned against the import and use of certain inorganic fertilizers, soil
amendments and/or other soils from offsite sources in the absence of specific information
relating to their chemical composition. Some fertilizers have been known to leach sulfate
compounds into soils otherwise containing "negligible" sulfate concentrations and increase the
sulfate concentrations to potentially detrimental levels. In some cases, concrete improvements
constructed in soils containing high levels of soluble sulfates may be affected by crystalline
growth or mineral accumulation, which may, in the long term, result in deterioration and loss of
strength.
Site Drainage
Homeowners should be made aware of the potential problems that may develop when drainage is
altered through construction of retaining walls, paved walkways, patios or other hardscape
improvements. Ponded water, drainage over the slope face, leaking irrigation systems,
overwatering or other conditions which could lead to ground saturation must be avoided.
^ No water should be allowed to flow over the slopes. No alteration of pad gradients
should be allowed that would prevent pad and roof runoff from being directed to
approved disposal areas.
> As part of site maintenance, all roof and pad drainage should be directed away from
slopes and around structures to approved disposal areas. All berms were constructed and
compacted as part of fine grading and should be maintained. Drainage patterns have
been established at the time of the fine grading should be maintained throughout the life
of the structure. No alterations to these drainage patterns should be made unless designed
by qualified professionals in compliance with local code requirements and site-specific
soils conditions.
Slope Drainage
> Homeowners should be made aware of the importance of maintaining and cleaning all
interceptor ditches, drainage terraces, downdrains, and any other drainage devices, which
have been installed to promote slope stability.
> Subsurface drainage pipe outlets may protrude through slope surfaces and/or wall faces.
These pipes, in conjunction with the graded features, are essential to slope and wall
stability and must be protected in-place. They should not be altered or damaged in any
way.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Planting and Irrigation of Slopes
> Seeding and planting of the slopes should be planned to. achieve, as rapidly as possible, a
well-established and deep-rooted vegetal cover requiring minimal watering.
> It is the responsibility of the landscape architect to provide such plants initially and of the
residents to maintain such planting. Alteration of such a planting scheme is at the
resident's risk.
> The homeowner is responsible for proper irrigation and for maintenance and repair of
properly installed irrigation systems. Leaks should be fixed immediately.
^ Sprinklers should be adjusted to provide maximum uniform coverage with a minimum of
water usage and overlap. Overwatering with consequent wasteful runoff and serious
ground saturation must be avoided.
> If automatic sprinkler systems are installed, their use must be adjusted to account for
seasonal and natural rainfall conditions.
Burrowing Animals
Homeowners must undertake a program to eliminate burrowing animals. This must be an
ongoing program in order to promote slope stability.
Improvements
Improvements (slabs, retaining walls, planters, etc.) should be designed to account for the terrain
of the project, as well as expansive soil conditions and chemical characteristics. Design
considerations on any given lot may need to include provisions for existing stabilization/ buttress
fills, differential bearing materials, ascending/descending slope conditions, bedrock structure,
perched (irrigation) water, special geologic surcharge loading conditions, expansive soil stresses,
and long-term creep/settlement.
All improvements should be designed and constructed by qualified professionals utilizing
appropriate design methodologies, which account for the on-site soils and geologic conditions.
Each lot and proposed improvement should be evaluated on an individual basis.
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
June 2, 2005
Setback Zones
Fill slopes will be manufactured onsite. Manufactured slopes may be subject to long-term
settlement and creep that can manifest itself in the form of both horizontal and vertical
movement. These movements typically are produced as a result of weathering, erosion, gravity
forces, and other natural phenomenon. A setback adjacent to slopes is required by most building
codes, including the Uniform Building Code. This zone is intended to locate and support the
residential structures away from these slopes and onto soils that are not subject to the potential
adverse effects of these natural phenomena.
Patios, walls, walkways, planters, etc. may be constructed within this zone. Such facilities may
be sensitive to settlement and creep and should not be constructed within the setback zone unless
properly engineered. It is suggested that plans for such improvements be designed by a
professional engineer who is familiar with hillside grading ordinances and design and
construction requirements associated .with hillside conditions. In addition, we recommend that
the designer and contractor familiarize themselves with the site specific geologic and
geotechnical conditions on the specific lot.
PACIFIC SOILS ENGINEERING, INC.