HomeMy WebLinkAbout3674; Poinsettia Lane Reach 3 - Hunsaker; Poinsettia Lane Reach 3; 1999-06-091 i to p "OIK P 0 ii Ai' :
GEOTECHNICAL INVESTIGATION
POINSETTIA LANE
("REACH 3")
CARLSBAD, CALIFORNIA
PREPARED FOR
HUNSAKER AND ASSOCIATES
SAN DIEGO, CALIFORNIA
JUNE 1999
GEOCON
INCORPORATED
GEOTECHNICAL CONSULTANTS
Project No. 06313-12-01
June 9, 1999
Hunsaker and Associates
10179 Huennekens Street
San Diego, California 92121
Attention: Mr. Ray Martin
Subject:
Gentlemen:
POINSETTIA LANE ("REACH 3")
CARLSBAD, CALIFORNIA
GEOTECHNICAL INVESTIGATION
In accordance with our Proposal No. LG-99155 and your authorization, we have performed a
geotechnical investigation of the proposed Poinsettia Lane ("Reach 3") alignment in Carlsbad,
California. The proposed Poinsettia Lane ("Reach 3") alignment will extend from its intersection
with Black Rail Road easterly to the existing Poinsettia alignment at approximate Station 162+90 for
a distance of approximately 1350 feet.
The accompanying report presents the results of our study and conclusions and recommendations
pertaining to the geotechnical aspects of developing the property as presently proposed. Provided the
recommendations of this report are followed, the site is considered suitable for roadway
development as currently planned.
If you should have any questions regarding this report, or if we may be of further service, please
contact the undersigned at your convenience.
Very truly yours,
GEOCON INCQ
RCE 22527
PD:AS:DFL:dmc
(6) Addressee
CERTIFIED
ENGINEERING
GEOLOGIST
Paul Dunster
RG6761
6960 Flanders Drive 558-6900
TABLE OF CONTENTS
1. PURPOSE AND SCOPE 1
2. SITE AND PROJECT DESCRIPTIONS 1
3. SOIL AND GEOLOGIC CONDITIONS 2
3.1 Compacted Fill (Qcf) . 2
3.2 Undocumented Fill (Qudf) 2
3.3 Topsoil/Colluvium (unmapped) 3
3.4 Alluvium (Qal) 3
3.5 Lindavista Formation (Qln) 3
3.6 Santiago Formation (Ts) 4
4. GROUNDWATER 4
5. GEOLOGIC HAZARDS 4
5.1 Faulting and Seismicity 4
5.2 Liquefaction 5
5.3 Landslides 6
6 . CONCLUSIONS AND RECOMMENDATIONS 7
6.1 General 7
6.2 Soil and Excavation Characteristics 7
6.3 Grading 8
6.4 Subdrains 9
6.5 Fill Slopes 10
6.6 Slope Stability 10
6.7 Preliminary Pavement Section 10
6.8 Slope Maintenance 11
6.9 Drainage 11
6.10 Grading Plan Review 12
LIMITATIONS AND UNIFORMITY OF CONDITIONS
MAPS AND ILLUSTRATIONS
Figure 1, Vicinity Map
Figure 2, Geologic Map
Figure 3, Cross Section A-A'
Figure 4, Fill Slope Stability Analysis
Figure 5, Surficial Slope Stability Analysis
Figure 6, Typical Subdrain Detail
Figure 7, Recommended Subdrain Cut-Off Wall
Figure 8, Subdrain Outlet Headwall Detail
APPENDIX A
FIELD INVESTIGATION
Figures A-l-A-19, Logs of Trenches
TABLE OF CONTENTS (Continued)
APPENDIX B
LABORATORY TESTING
Table B-I, Summary of Laboratory Maximum Dry Density and Optimum Moisture
Content Test Results
Table B-II, Summary of Laboratory Direct Shear Test Results
Table B-III, Summary of Laboratory Expansion Index Test Results
APPENDIX C
RECOMMENDED GRADING SPECIFICATIONS
GEOTECHNICAL INVESTIGATION
1. PURPOSE AND SCOPE
This report presents the results of a geotechnical investigation for Poinsettia Lane ("Reach 3"). The
subject site is located south of Palomar Airport Road, between Poinsettia Lane's intersection with
Black Rail Road, and the existing Poinsettia lane alignment at approximate Station 162+90, in
Carlsbad, San Diego County, California (Figure 1). The purpose of this report was to evaluate
surface and subsurface soil and geologic conditions and, based on those conditions, provide
recommendations pertaining to the geotechnical aspects of improving the roadway as proposed.
The scope of this geotechnical investigation consisted of performing a geologic reconnaissance and
the excavation of 19 backhoe trenches and geologic mapping. The approximate locations of the
exploratory excavations are depicted on Figure 2. Logs of the exploratory trenches are presented in
Appendix A. Our scope also included a review of:
1. Report of Preliminary Geotechnical Investigation [for] DeJong Property (APN 215-080-01),
Carlsbad, California, prepared by Geotechnical Exploration Incorporated, dated January 12,
1998,
2. Final Report of Testing and Observation Services During Site Grading [for] Black Rail
Road (Approximate Station 15+10 to Sapphire Drive) Off-site Cobblestone Sea Village
Units 1 and 2, Carlsbad, California, prepared by Geocon Incorporated, dated April 6, 1999,
3. California DMG Open-File Report 96-02 entitled Geologic Maps of the Northwestern Part
of San Diego County, California, and
4. An improvement map entitled Grading and Improvement Plans for Poinsettia Lane,
prepared by Hunsaker & Associates, undated.
Laboratory tests were performed on selected soil samples to evaluate pertinent physical properties.
Details of the field investigation and laboratory tests are presented in Appendices A and B.
The recommendations presented herein are based upon an analysis of the data obtained in the
referenced reports, observations during this investigation and our experience with similar soil and
geologic conditions.
2. SITE AND PROJECT DESCRIPTIONS
The Poinsettia Lane ("Reach 3") alignment which is located in Carlsbad, California consists of
approximately 1,350 feet of future road alignment. The proposed road alignment is bounded on the
Project No. 06313-12-01 -1- June 10, 1999
east and west sides by existing reaches of Poinsettia Lane, and to the north and south the property is
surrounded by rural/natural and agriculturally-developed properties.
Topographically, the property consists of a slope descending from an elevation of approximately 370
feet Mean Sea Level (MSL) in the west to a steeply-incised brush-filled gully in the east at an
elevation of approximately 260 feet MSL. The site drains primarily to the north and east. Site
vegetation generally consists of native weeds, grasses, scattered trees and bushes. Some of the
property has been cultivated in the past, and there are partially ruined buildings and trailers in the
western and eastern portions of the site. Fences, firewood piles, debris, dirt roads, end dumped soil,
overhead powerlines, and a reclaimed water pipeline were observed on the property.
3. SOIL AND GEOLOGIC CONDITIONS
Five surficial soil types and two geologic formations underlying the proposed roadway alignment
were encountered during this field investigation. The surficial units include topsoil, undocumented
fill and debris, previously placed compacted fill, alluvium, and colluvium. The Formational units
encountered includes the Pleistocene-aged terrace deposit known as the Lindavista Formation
underlain by the Eocene-aged Santiago Formation. The soil types and geologic formation are
discussed below in order of increasing age.
3.1 Compacted Fill (Qcf)
Compacted fill was encountered at the western end of the proposed alignment. As documented in the
referenced grading report, this fill was placed under the observation of Geocon Incorporated during
the period of March 11 through July 30, 1998, as part of the testing and observation services
provided during the site grading for a portion of Black Rail Road (Reference No. 2). During the
development of "Reach 3", this existing fill should be "benched", prior to placing additional
compacted fill against it. The fill generally consisted of medium dense, damp, silty, fine to coarse
sand. In exploratory Trenches T-12 and T-13, medium dense Terrace Deposits were encountered at
4'/2 and 3 feet below ground surface, respectively.
3.2 Undocumented Fill (Qudf)
Undocumented fill and debris consisting of wood, plastic, household debris, and other refuse was
observed over a large area in the vicinity of exploratory Trenches T-4, T-5, and T-18. Smaller areas
covered with similar debris were noted in the vicinity of exploratory Trenches T-6, T-7, T-19 and
T-16. End dumped soils were noted in the western portion of the project in the vicinity of Trench
T-12. Other areas of undocumented fill may exist but were not observed. This is common where
Project No. 06313-12-01 -2- June 10, 1999
agricultural activities may have masked the presence of such materials. It is recommended that all
undocumented fill soils be removed and properly recompacted. Any debris or deleterious material
should be removed and disposed of off-site.
3.3 Topsoil/Colluvium (unmapped)
Topsoils and Colluvial materials on the order of 1 to 8 feet generally blanket the majority of the
subject property. The soils generally consist of very loose to loose, porous, dry to saturated, silty,
fine to coarse sand. Areas of deeper colluvium may occur within the proposed alignment. These soils
in their present condition are compressible and are not considered suitable to receive improvements
and will require remedial grading in the form of complete removal and recompaction.
3.4 Alluvium (Qal)
Alluvial materials were encountered in exploratory Trenches T-3 and T-4 within the natural drainage
valley that runs approximately north-south under the proposed eastern portion of the road alignment.
Smaller amounts of alluvium were noted in exploratory Trench T-16. The alluvium generally
consists of loose, damp to saturated, porous, silty to clayey sand. Observations of the alluvium
within the trenches excavated during this field investigation indicate that the alluvium is up to 9 feet
in thickness. Areas of deeper alluvium may occur within this valley. The alluvium in its present
condition is compressible and is not considered suitable to receive improvements and will require
remedial grading in the form of complete removal and recompaction.
3.5 Lindavista Formation (Qln)
Pleistocene marine terrace deposits of the Lindavista Formation were encountered over the western
portion of the site. This unit generally consisted of predominantly medium dense, light brown,
moderate brown and greyish orange, silty, fine- to coarse-grained sandstone with varying amounts of
fine-grained rounded gravel, and partially-cemented zones. It is anticipated that the majority of any
excavation within this unit can be accomplished with conventional, moderate to heavy-duty grading
equipment. Heavy ripping will be required for excavations in localized areas of highly cemented
sandstone and/or conglomerate. Some oversized cemented chunks may be generated. Any oversized
material (i.e., material greater than 12 inches in maximum dimension) will require special handling
and placement as recommended hereinafter. In general, the Lindavista Formation possesses excellent
foundation bearing characteristics in either a natural or properly compacted condition. The majority
of these materials are anticipated to have a low to medium expansion potential.
Project No. 06313-12-01 -3- June 10, 1999
3.6 Santiago Formation (Ts)
The Eocene-aged Santiago Formation unconformably underlies the Lindavista Formation in the
eastern portion of the project site. The Santiago Formation encountered generally consisted of dense,
massive, very pale orange, greyish orange, pale and dark yellowish orange, slight to moderately
weathered, clayey/silty, fine to coarse sandstone and well-graded sandstone. Some zones of hard,
greenish gray to brown claystone and siltstone have been observed in other areas close to the site and
should be expected. Flat-lying interbeds were observed in exploratory Trench T-3. It is anticipated
that the majority of the excavation within this unit can be accomplished with conventional, moderate
to heavy-duty grading equipment. The claystone and siltstone members of the Santiago Formation
are stratigraphically equivalent to the Eocene-aged Friars Formation. Cut slope stabilization
measures are frequently required for excavations within the clayey members due to the presence of
inherently weak claystone beds, bedding plane shear surfaces, and groundwater seepage.
Typically, the sandstone member of the Santiago Formation possesses excellent foundation bearing
characteristics in either an undisturbed and/or properly compacted condition. The claystone and
siltstone portions of the Santiago Formation, however, are generally weaker, and are moderately to
highly expansive. In general, highly expansive soils should be placed in deeper fill areas and away
from the face of the slope.
4. GROUNDWATER
Groundwater was encountered in several of the exploratory trenches. Flowing water and seepage was
typically noted within the surficial soils and at their contact with the underlying formational units. A
subdrain should be installed following removal of alluvium from the steeply incised gully at the
eastern end of the proposed alignment. Other smaller gullies and tributary canyons may be exposed
during surficial soil removals. Additional subdrains should be installed to control any water that may
enter these drainages prior to placing compacted fill. Grading should be periodically observed by an
engineering geologist to evaluate the necessity for these additional subdrains. Specific subdrain
recommendations will be presented in the Conclusions and Recommendations portion of this report.
5. GEOLOGIC HAZARDS
5.1 Faulting and Seismicity
A review of geologic literature, experience with the soil and geologic conditions in the general area,
and observations during the field investigation indicate that no active faults are located at the site.
The nearest known active fault is the Rose Canyon Fault Zone located approximately 6 miles west of
Project No. 06313-12-01 -4- June 10, 1999
the site. Maximum Credible and Maximum Probable seismic events of Magnitude 6.90 and
Magnitude 5.70, respectively, are postulated for the Rose Canyon Fault Zone.
The estimated Maximum Credible and Maximum Probable peak site accelerations are 0.31 g and
0.17 g, respectively. The maximum effective ground motion, however, is estimated to be approxi-
mately 0.22 g for the same seismic event. The effective ground motion is associated with the
significant part of the ground motion containing repetitive motions that possess strong energy
content and that produce structural deformation. It has been estimated by Ploessel and Slosson
(1974) that effective ground acceleration is equal to approximately 65 to 70 percent of the peak
ground motion for earthquakes within 20 miles of a site. Seismic parameters for some other regional
faults capable of generating ground acceleration at the site are summarized below.
TABLE 5.1.
DETERMINISTIC SITE PARAMETERS FOR SELECTED FAULTS
Fault Name
Rose Canyon
Newport-Inglewood-Offshore
Palos Verdes
Coronado Banks
Elsinore-Glen Ivy
Elsinore-Temecula
Elsinore-Julian
Distance
From Site
(miles)
6
9
40
21
37
24
24
Maximum Credible Event
Maximum
Credible
(Mag.)
6.90
6.90
7.10
7.40
6.80
6.80
7.10
Peak Site
Acceleration
(g)
0.31
0.24
0.07
0.16
0.06
0.10
0.12
Maximum Probable Event
Maximum
Probable
(Mag.)
5.70
5.80
6.20
6.30
6.30
6.30
6.40
Peak Site
Acceleration
(g)
0.17
0.13
0.03
0.08
0.04
0.07
0.07
It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of
a major earthquake along any of the above mentioned faults, however, the seismic risk at the site is
not considered to be significantly different than that of the surrounding developments of similar
geologic settings in the Carlsbad area.
5.2 Liquefaction
Liquefaction occurs in loose cohesionless soils located below the water table that are subjected to
large accelerations during strong earthquakes. Due to the very dense nature of the formational units,
the removal and recompaction of the surficial soils, the installation of subdrains, and the lack of a
permanent groundwater table, the potential for liquefaction of the site subsoils is considered to be
very low.
Project No. 06313-12-01 June 10, 1999
5.3 Landslides
Evidence of landslides on the subject property was not observed in our review of aerial photographs,
geologic maps, or during on-site field investigations.
Project No. 06313-12-01 - 6 - June 10, 1999
6. CONCLUSIONS AND RECOMMENDATIONS
6.1 General
6.1.1 No soil or geologic conditions were encountered during this geotechnical investigation
performed by Geocon Incorporated that would preclude the development of the property
provided that the recommendations of the report are followed.
6.1.2 The surficial soils such as the undocumented fill alluvium, colluvium and topsoil within \
areas of planned development are considered unacceptable to receive improvements in
their present condition and will require remedial grading in the form of removal and
recompaction. Also, the existing structures and trash will need to be removed and disposed /
of off-site.
6.1.3 It is our understanding that the majority of the fill material will be imported from offsite. \
Geocon Incorporated should test imported soil for expansion potential and compaction j
characteristics prior to it being imported to the site. Any large chunks of cemented
sandstone imported to the site will require special handling and placement. /
6.2 Soil and Excavation Characteristics
6.2.1 The soil conditions encountered were low expansive sands derived from the Lindavista
and Santiago Formations. However, some clayey materials should be anticipated from the
imported soils, and on-site. These clayey materials are highly expansive and in general
should not be placed as fill in the outer 3 feet of any fill slope face and/or within 10 feet of
finish fill grade. Claystone material should be placed in the deeper portion of fill areas
away from the slope zone.
6.2.2 It is anticipated that the surficial deposits can be excavated with a light effort using
conventional heavy-duty grading equipment. A moderate to heavy effort is anticipated for
excavations within the formational sedimentary units. Oversize materials in the form of
cemented chunks and/or slabs of sandstone may be generated during excavation of
portions of the Lindavista and Santiago Formations. Oversized rock or slabs should be
broken so that no rock fragments greater than 4 feet in maximum dimension are placed in
fills. Oversized rocks should be placed in accordance with the Recommended Grading
Specifications in Appendix C. It is recommended that prior to beginning grading,
acceptable areas and methods of rock disposal be designated and reserved for the
placement of rock as it is encountered.
Project No. 06313-12-01 -7- June 10, 1999
6.3 Grading
6.3.1 All grading should be performed in accordance with the Recommended Grading
Specifications in Appendix C and the City of Carlsbad Grading Ordinance. Where the
recommendations of this section conflict with those in Appendix C, the recommendations
of this section take precedence. All earthwork should be observed and all fills tested for
proper compaction by Geocon Incorporated.
6.3.2 Prior to commencing grading, a preconstruction conference should be held at the site with
the owner or developer, grading contractor, civil engineer and geotechnical engineer in
attendance. Special soil handling and/or the grading plans can be discussed at that time.
6.3.3 Site preparation should begin with the removal of existing structures, debris, vegetation,
and all deleterious material. The depth of removal should be such that material exposed in
cut areas or soils to be used as fill are relatively free of organic matter. Material generated
during stripping and/or site demolition should be exported from the site.
6.3.4 All compressible surficial soil deposits (undocumented fill, topsoil, colluvium and
alluvium) within areas of planned grading should be removed to firm natural ground and
properly compacted prior to placing additional fill and/or structural loads.
6.3.5 The actual extent of unsuitable soil removals will be determined in the field during
grading by the soil engineer and/or engineering geologist. Overly wet surficial soils will
require drying and/or mixing with drier soils to facilitate proper compaction.
6.3.6 After removal of unsuitable materials as recommended above is performed, the site should
then be brought to final subgrade elevations with structural fill placed and compacted in
layers. Prior to placing fill, the exposed natural ground surface should be scarified to a
depth of at least 12 inches, moisture conditioned and compacted. In general, soils native to
the site are suitable for use as fill if free from vegetation, debris and other deleterious
material. Layers of fill should be no thicker than will allow for adequate bonding and
compaction. All fill, including scarified ground surfaces, should be compacted to at least
90 percent of laboratory maximum dry density in accordance with ASTM Test Procedure
D-1557-91, at or slightly above optimum moisture content. Fills deeper than 50 feet
should be compacted to at least 92 percent of the laboratory maximum dry density. Fill
materials with in-place density test results indicating moisture contents less than optimum
will require additional moisture conditioning before placing additional fill.
Project No. 06313-12-01 -8- June 10, 1999
6.3.7 Oversize cemented sandstone chunks (defined as material greater than 12 inches in
nominal dimension) will likely be generated during grading within the Formational units.
Placement of oversize materials within fills should be performed in accordance with the
recommendations in Appendix C.
6.3.8 Grading operations should be scheduled so as to permit the placement of oversized rock
and expansive soils (if encountered) in the deeper fills. Oversized rock should be placed at
least 5 feet below finish grade or 3 feet below the deepest utility, whichever is greater.
6.4 Subdrains
6.4.1 Subdrains (Figure 6) should be installed in the canyons to be filled. The subdrains should
extend up the canyons to approximately 10 feet below ultimate finish grade elevations
and/or at least 2 feet below any proposed utility.
6.4.2 The lower 20 feet of subdrains exiting the base of compacted fill slopes should consist of
nonperforated pipe. A cutoff wall (Figure 7) should be constructed immediately below the
junction of the perforated pipe with the non perforated pipe. The cutoff wall should extend
at least 6 inches beyond the sides and bottom of the subdrain trench and 6 inches above the
top of the pipe.
6.4.3 Where subdrain systems do not outlet into permanent structures such as storm drains, the
outlet pipe should be provided with a concrete headwall (Figure 8), riprap, or similar
device.
6.4.4 Anticipated locations of subdrains will be designated on the improvement plans during
review by Geocon, Incorporated when plans are available. Actual locations may vary and
final installation will be determined during grading.
6.4.5 After installation of the subdrains, the project Civil Engineer should survey the locations
and prepare accurate As-built plans of the subdrain locations. The project soils engineer
should verify the as-built subdrain outlet. The contractor should ensure that an adequate
drainage gradient is maintained throughout the system, and that the subdrain outlet is free
of obstructions.
Project No. 06313-12-01 - 9 - June 10, 1999
6.5 Fill Slopes
6.5.1 The outer 15 feet of fill slopes, measured horizontal to the slope face, should be composed
of properly compacted granular "soil" fill to reduce the potential for surface sloughing.
6.5.2 All fill slopes should be overbuilt at least 3 feet horizontally, and cut to the design finish
grade. As an alternative, fill slopes may be compacted by back-rolling at vertical intervals
not to exceed 4 feet and then track-walking with a D-8 dozer, or equivalent, upon
completion such that the fill soils are uniformly compacted to at least 90 percent relative
compaction to the face of the finished slope.
6.5.3 All slopes should be planted, drained and properly maintained to reduce erosion.
6.6 Slope Stability
6.6.1 Slope stability analysis utilizing average drained direct shear strength parameters based on
laboratory tests and experience with similar soil types in nearby areas indicates that the
proposed fill slopes, constructed of on-site materials, should have calculated factors of
safety of at least 1.5 under static conditions for both deep-seated failure and shallow
sloughing conditions. Slope stability calculations are presented on Figures 4 and 5.
6.7 Preliminary Pavement Section
6.7.1 Based on R-value tests performed on granular material derived from the Lindavista
Formation from a nearby property, an assumed R-Value of 30 was used to evaluate
preliminary pavement sections. A Traffic Index (TI) of 8.5 has been assumed for
Poinsettia Lane. Utilizing the California Flexible Pavement Design procedure, and the
City of Carlsbad minimum requirements, pavement sections were determined and are
presented in Table 6.9. It should be noted that these pavement sections are preliminary.
Grading operations should consider capping the roadway subgrade to a depth of 3 feet
with granular imported soils. This should provide higher R value subgrade soils and result
in decreasing the pavement section. The final pavement recommendations will be provided
for City of Carlsbad approval after finish subgrade is achieved and R-Value tests are
performed on the actual subgrade soils.
Project No. 06313-12-01 -10- June 10, 1999
TABLE 6.7
PRELIMINARY PAVEMENT SECTIONS
Location
Poinsettia Lane
Assumed
Traffic Index
8.5
Asphalt Concrete
(inches)
5
Class 2
Aggregate Base
(inches)
12
6.7.2 Base course material should consist of aggregate base and be properly moisture
conditioned and compacted to a minimum relative compaction (ASTM Dl557-91)
of 95 percent at or above optimum moisture content. The upper 12 inches of subgrade soil
should also be moisture-conditioned and compacted to a minimum relative compaction of
95 percent.
6.7.3 Aggregate base and asphalt concrete should conform to City of Carlsbad Standards.
6.8 Slope Maintenance
6.8.1 Slopes that are steeper than 3:1 (horizontal:vertical) may, under conditions which are both
difficult to prevent and predict, be susceptible to near surface (surficial) slope instability.
The instability is typically limited to the outer three feet of a portion of the slope and
usually does not directly impact the improvements on the pad areas above or below the
slope. The occurrence of surficial instability is more prevalent on fill slopes and is
generally preceded by a period of heavy rainfall, excessive irrigation, or the migration of
subsurface seepage. The disturbance and/or loosening of the surficial soils, as might result
from root growth, soil expansion, or excavation for irrigation lines and slope planting, may
also be a significant contributing factor to surficial instability. It is, therefore, recom-
mended that, to the maximum extent practical: (a) disturbed/loosened surficial soils be
either removed or properly recompacted, (b) irrigation systems be periodically inspected
and maintained to eliminate leaks and excessive irrigation, and (c) surface drains on and
adjacent to slopes be periodically maintained to preclude ponding or erosion. It should be
noted that although the incorporation of the above recommendations should reduce the
potential for surficial slope instability, it will not eliminate the possibility, and, therefore,
it may be necessary to rebuild or repair a portion of the project's slopes in the future.
6.9 Drainage
6.9.1 Establishing proper drainage is imperative to reduce the potential for differential soil
movement, erosion and subsurface seepage. Positive measures should be taken to properly
Project No. 06313-12-01 June 10, 1999
finish grade the improvements so that drainage water is directed away from pavement and
the tops of slopes into controlled drainage devices. Experience has shown that even with
these provisions, a shallow groundwater or subsurface condition can and may develop in
areas where no such condition existed prior to site development. This is particularly true
where a substantial increase in surface water infiltration results from an increase in
landscape irrigation.
6.10 Grading Plan Review
6.10.1 The geotechnical engineer and engineering geologist should review the grading plans prior
to finalization to verify their compliance with the recommendations of this report and
determine the necessity for additional comments, recommendations and/or analysis.
Project No. 06313-12-01 -12- June 10, 1999
LIMITATIONS AND UNIFORMITY OF CONDITIONS
1. The recommendations of this report pertain only to the site investigated and are based upon
the assumption that the soil conditions do not deviate from those disclosed in the
investigation. If any variations or undesirable conditions are encountered during
construction, or if the proposed construction will differ from that anticipated herein, Geocon
Incorporated should be notified so that supplemental recommendations can be given. The
evaluation or identification of the potential presence of hazardous or corrosive materials was
not part of the scope of services provided by Geocon Incorporated.
2. This report is issued with the understanding that it is the responsibility of the owner, or of his
representative, to ensure that the information and recommendations contained herein are
brought to the attention of the architect and engineer for the project and incorporated into the
plans, and the necessary steps are taken to see that the contractor and subcontractors carry
out such recommendations in the field.
3. The findings of this report are valid as of the present date. However, changes in the
conditions of a property can occur with the passage of time, whether they be due to natural
processes or the works of man on this or adjacent properties. In addition, changes in
applicable or appropriate standards may occur, whether they result from legislation or the
broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly
or partially by changes outside our control. Therefore, this report is subject to review and
should not be relied upon after a period of three years.
Project No. 06313-12-01 June 10, 1999
4 VESPER Ul °:.«UEBH?. ?. '%5 PBLINA CT i: 'iV!£ 3:c/.
SOURCE: 1999 THOMAS BROTHERS MAP
SAN DIEGO COUNTY, CALIFORNIA
REPRODUCED WITH PERMISSION GRANTED BY THOMAS BROTHERS MAPS.
THIS MAP IS COPYRIGHTED BY THOMAS BROS. MAPS. IT IS UNLAWFUL TO COPY
OR REPRODUCE ALL OR ANY PART THEREOF, WHETHER FOR PERSONAL USE OR
RESALE. WITHOUT PERMISSION
N
NO SCALE
GEOCON <gS>
INCORPORATED ^SS^
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121-2974
PHONE 619 558-6900 - FAX 619 558-6159
PD/GBP DSK/DOOOD
VICINITY MAP
POINSETTIA LANE
("REACH 3")
CARLSBAD, CALIFORNIA
DATE 06-10-1999 PROJECT NO. 06313-12-01 FIG. 1
ivici
A
270 -i
280-
290-
300^
GEOCON LEGEND
ALLUVIUM
7S SANTIAGO FORMATION
, EXISTING GRADE
T-4
E/RU/GEOTKH/6313PO.DWG/PACO
PROPOSED GRADE
CROSS SECTION A-A'
SCALE 1" = 40'
POINSETTIA LANE
("REACH 3")
CARLSBAD, CALIFORNIA
A1
,— 270
-280
-290
L300
GEOCON
INCORPORATED
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 619 558-6900 - FAX 619 558-6159
PROJECT NO. 06313 -12 - 01
FIGURE 3
DATE 06-10-1999
PROJECT NO. 06313-12-01
ASSUMED CONDITIONS:
Slope Height
Slope Inclination
Total Unit Weight of Soil
Angle of Internal Friction
Apparent Cohesion
No Seepage Forces
H = 50 feet
2:1 (Horizontal:Vertical)
y, =125 pounds per cubic foot
<|> = 28 degrees
C =390 pounds per square foot
ANALYSIS:
Equation (3-3), Reference 1
Equation (3-2), Reference 1
Calculated Using Eq. (3-3)
Determined Using Figure 10, Reference 2
Factor of Safety Calculated Using Eq. (3-2)
FS =
FS =
REFERENCES:
(1) Janbu, N., Stability Analysis of Slopes with Dimensionless Parameters, Harvard Soil Mechanics,
Series No. 46, 1954.
(2) Janbu, N., Discussion of J.M. Bell, Dimensionless Parameters for Homogeneous Earth Slopes,
Journal of Soil Mechanics and Foundation Design, No. SM6, November 1967.
FILL SLOPE STABILITY ANALYSIS
POINSETTIA LANE
("REACH 3")
CARLSBAD, CALIFORNIA
FIGURE 4
PROJECT NO. 06313-12-01
ASSUMED CONDITIONS:
Slope Height H ' = Infinite
Depth of Saturation Z = 3 feet
Slope Inclination 2:1 (Horizontal:Vertical)
Slope Angle i = 26.5 degrees
Unit Weight of Water yw = 62.4 pounds per cubic foot
Total Unit Weight of Soil yt = 125 pounds per cubic foot
Angle of Internal Friction <(> = 28 degrees
Apparent Cohesion C = 390 pounds per square foot
Slope saturated to vertical depth Z below slope face.
Seepage forces parallel to slope face
ANALYSIS:
= 3.1
REFERENCES:
Yt Z sin i cos /
(1) Haefeli, R. The Stability of Slopes Acted Upon by Parallel Seepage, Proc. Second International
Conference, SMFE, Rotterdam, 1948, 1, 57-62.
(2) Skempton, A. W., and F. A. Delory, Stability of Natural Slopes in London Clay, Proc. Fourth
International Conference, SMFE, London, 1957, 2, 378-81.
SURFICIAL SLOPE STABILITY ANALYSIS
POINSETTIA LANE
("REACH 3")
CARLSBAD, CALIFORNIA
FIGURE 5
APPROVED FILTER FABRIC
6" DIA. PERFORATED
SUBDRAIN PIPE
1" MAX. OPEN-GRADED
AGGREGATE 9 CUBIC FT./FT.
MINIMUM
NOTES:
1 SUBDRAIN PIPE SHOULD BE 6-INCH MINIMUM DIAMETER, PERFORATED, THICK
WALLED SCHEDULE 40 PVC, SLOPED TO DRAIN AT 1 PERCENT MINIMUM AND
CONNECTED TO STORM DRAIN SYSTEM OR APPROVED OUTLET.
2 WHERE DRAIN EXCEEDS 500 FEET, PIPE DIAMETER SHOULD BE INCREASED
TO 8 INCHES
3 FILTER FABRIC TO BE MIRAFI 140N OR EQUIVALENT
NO SCALE
TYPICAL SUBDRAIN DETAIL
GEOCON <^>
INCORPORATED ^*SOr
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 • 2974
PHONE 619 558-6900 • FAX 619 558-6159
PD / GBP DSK/EOOOO
POINSETTIA LANE
("REACH 3")
CARLSBAD, CALIFORNIA
DATE 06-10-1999 PROJECT NO. 06313 - 12 - 01 FIG. 6
SD / IXVIII / RSS
FRONT VIEW
CONCRETE
CUT-OFF WALL
6" MIN. (TYP)
6" MIN. (TYP)
NO SCALE
SIDE VIEW
CONCRETE
CUT-OFF WALL-
SOLID SUBDRAIN PIPE
12" MIN.
6" MIN. (TYP).
PERFORATED SUBDRAIN PIPE
6" MIN. (TYP)
NO SCALE
RECOMMENDED SUBDRAIN CUT-OFF WALL
GEOCON ®>
INCORPORATED ^SKF
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 619 558-6900 - FAX 619 558-6159
PD/GBP DSK/EOOOD
POINSETTIA LANE
("REACH 3")
CARLSBAD, CALIFORNIA
DATE 06-10-1999 PROJECT NO. 06313 - 12 - 01 JFIG. 7
RSCOW VI/IXVIIRSS
FRONT VIEW
6"
SUBDRAIN
18"
12"
24"
NO SCALE
SIDE VIEW
NOTE : HEADWALL SHOULD OUTLET AT TOE OF FILL SLOPE
OR INTO CONTROLLED SURFACE DRAINAGE NO SCALE
SUBDRAIN OUTLET HEADWALL DETAIL
GEOCON ®>
INCORPORATED ^SiSr
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 -2974
PHONE 619 558-6900 - FAX 619 558-6159
PD / GBP | DSK/GTYPD
POINSETTIA LANE
("REACH 3")
CARLSBAD, CALIFORNIA
DATE 06-10-1999 PROJECT NO. 06313-12-01 FIG. 8
SOHD / VIII-IXVRSS
I
E
i
I
I
E
I
C
C
i"V
C
c
C
C
E
1
E
I
APPENDIX A
FIELD INVESTIGATION
The field investigation was performed on May 13 and 17, 1999, and consisted of a visual site
reconnaissance, and the excavation of 19 backhoe trenches. The approximate locations of the
exploratory trenches are shown on Figure 2.
The backhoe trenches were advanced to depths varying from 3 to 11 feet using a track-mounted
backhoe equipped with a 24-inch-wide bucket.
The soils encountered in the exploratory excavations were visually examined, classified, and logged.
Logs of the backhoe trenches are presented on Figures A-l through A-19. The logs depict the soil
and geologic conditions encountered.
Project No. 06313-12-01 June 10, 1999
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
- 2 -
- 4 -
-
SAMPLE
NO.
Tl-2
Tl-1
CDo4
H
-1
~ 1 1 -|.]-, 1
T 1•I'll
'. •'.- •'.'•
'• ~ - ''-.'•
trLU
<E
C
Oa:CD
SOIL
CLASS
(USCS)
SM
SW
TRENCH T 1
ELEV. (MSL.) 312 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Loose dry moderate yellowish brown Silty fine _
\ SAND /
SANTIAGO FORMATION
Medium dense, damp, grayish orange, well graded,
fine to coarse SAND, slightly weathered, massive,
scattered, randomly oriented joints up to 1/8"
wide, black silt filled
TRENCH TERMINATED AT 6 FEET
oW~Hyi-(-JFU.<rS\
£"^
UJCOO
Q. ^
_
>
1^^ .
>w
a
~
Ife
^^ J^£~* f~l
CJ
Figure A-l, Log of Trench T 1 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
£1 ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 2 -
-
- 4 -
- 6 -
- fi
_
11)
SAMPLE
NO.
T2-1 1
11I
3_LITHOLOG'•I-1-'--,. 1 -
i-- 1 L
.-!• •'-•i- 1 -l-j't..
-'i ":•!••••
1
:[}•;
" /- " .-•'.'
•'.-:• ".-:••
a:HI
GROUNDUA1SOIL
CLASS
(USCS)
SM
sw
TRENCH T 2
ELEV. (MSL.) 300 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Loose, damp, dark yellowish brown, porous, Silty,
fine to medium SAND, becomes moister with
depth, prevalent sloughing of trench walls,
common
_^ -Slight seepage at contact(less than 1/2 gpm) ^_
SANTIAGO FORMATION
Medium dense, damp, grayish orange, well graded,
fine to medium SAND, slightly to moderately
weathered, massive, scattered, randomly oriented
joints up to 1/8" wide, black silt filled
TRENCH TERMINATED AT 10 FEET
Z <*N
ENETRATIORESISTANCEBLOWS/FT.Q_fc*"^'
_
-
-
-
5_
1
a
96.6
^MOISTUREONTENT (Xo
9.0
Figure A-2, Log of Trench T 2 PLR3
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL
ii ... DISTURBED OR BAG SAMPLE
C . . . STANDARD PENETRATION TEST
B . . . CHUNK SAMPLE
... DRIVE SAMPLE (UNDISTURBED)
... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 2 -
_
-4-i
- 6 -
- 8 -
- 10 -
SAMPLE
NO.
T3-1 r
1
1T3-2
T3-3
i
1i
?T3-4 1
I
CD
ITHOLO_i
'/: '/:/.
v//
/S'/7./://
"///
ty/-
/ S
'^'/
fa
%
§
£/X' .i/l 'y/I- i/l
')\4'JC.yTf/
y yXT i/l
If -!/l '¥n
a:UJi—
c
oCLCD
SOIL
CLASS
(USCS)
sc
SC/SM
TRENCH T 3
ELEV. (MSL.) 275 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
ALLUVIUM
Loose, damp to moist, pale yellowish brown,
Clayey, fine to medium SAND, porous, abundant
rootlets (fine)
-Slight seepage at contact
SANTIAGO FORMATION
Medium dense, damp, mottled, grays, dark
yellowish orange, grayish orange, Silty, Clayey,
fine to medium SAND, slightly weathered, weak,
poorly defined undulatory, approximately flat
~\ bedding, scattered rootlets /~
TRENCH TERMINATED AT 1 1 FEET
ZLU~
£ik
iLlrnO
Lu^mQ_a:w
:_
-
_
>•
«C
go
•£^
Q
101.4
~
||
^0o
7.5
Figure A-3, Log of Trench T 3 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
H ... DISTURBED OR BAG SAMPLE K ... CHUNK SAMPLE T. ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
.
- 4 -
- 6 -
SAMPLE
NO.
5T4-1
V
>_
COa
LITHOL"-1. ' •• -•''I
•i T .
V-'-•j. i -
-1- •'-
T '• V -< I rX - , HX 1 ' "x • . i • -
< " I* ' "
* 1 - L
VI1 -- 1 1.
•j-T
a:LUi—<r
GROUNDUSOIL
CLASS
(USCS)
SM
SM
SM
TRENCH T 4
ELEV. (MSL.) 310 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Loose, damp, dark yellowish brown, Silty, fine to
medium SAND, abundant roots
ALLUVIUM
Loose, damp, moderate yellowish brown, fine to
coarse Silty SAND, porous
SANTIAGO FORMATION
Medium dense, damp to wet, mottled dark
yellowish orange, grays, Silty, fine to medium
SAND, massive, moderately weathered
TRENCH TERMINATED AT 7 FEET
z ^o^ .HCJ,ENETRAT]JESISTANBLOUS/F1Q- ^
_
_
—
>_
h~
H
Q
^1 1 1 *^MOISTURONTENT <a
Figure A-4, Log of Trench T 4 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL E... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
H ... DISTURBED OR BAG SAMPLE K ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 2 -
- 4 -
- 6 -
SAMPLE
NO.
T5-1
T5-2
T5-3
I
71|1
i
CD
LITHOLO".1 ''-•.
"-,. \ -,
-, I- iA \- -
:j}-
:]}•
4-1"T ^ ~-, i
- i--•1-.|- -J-
o:u.GROUNDWASOIL
CLASS
(USCS)
SM
SM
TRENCH T 5
ELEV. (MSL.) 314 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOH7COLLUVIUM
Loose to very loose, damp, moderate brown to
dark yellowish brown, Silty, fine to medium
SAND, porous
-Slight seepage at contact
SANTIAGO FORMATION
Medium dense, damp, dark yellowish orange, Silty,
fine to medium SAND, moderately weathered,
massive
TRENCH TERMINATED AT 8 FEET
ZLJ'--ENETRATICJESISTANCBLOWS/FT.Q. ^
_
_
>
|j
Q
~MOISTUREONTENT Oo
- Figure A-5, Log of Trench T 5 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST
81 ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE
... DRIVE SAMPLE (UNDISTURBED)
... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 2 -
-
- 4 -
-
SAMPLE
NO.LITHOLOGY~.j '!.-
"-,. I -
-, iI.-!• -1-
_\l -
.-I-}-'-
:\ } -
•1. ••--,. i-I.:1.};-
•! t GROUNDWATER |SOIL
CLASS
(USCS)
SM
TRENCH T 6
ELEV. (MSL.) 295 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Very loose, (caving) saturated, moderate brown,
Silty, fine to coarse SAND, trench caving, cannot
enter, flowing water
SANTIAGO FORMATION
Medium dense to loose, damp to wet, mottled
\ grays, pale and dark yellowish orange, moderately /
\ weathered, massive, random discontinuous joints /
\ stained black /
TRENCH TERMINATED AT 7 FEET
DID NOT ENTER CAVING TRENCH ENETRATIONRESISTANCEBLOWS/FT.)Q- ^
_
~
-RY DENSITY(P.C.F.)a MOISTUREONTENT (X)u
Figure A-6, Log of Trench T 6 PLR3
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL
l§ ... DISTURBED OR BAG SAMPLE
C ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED)
B ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
_ ,
- 4 -
-
6 ~
-
- 8 -
ID
SAMPLE
NO.
>-CDO
O
1—H
"1 1 -
•"'' •)""1
'j \•1 j.
"1 ' '• " r•j- 1 -
•1 !-•-it"'j -f. --i j."1~ j "i-!~"i -1
* 1 L
-•'• ' 'i. •-i -•i -.•i- r -i. '
;|J'-
;l};
]-!;.
i ' "•It
trLUi—
~T
2
O
CD
SOIL
CLASS
(USCS)
SM
SM
SM
SM
TRENCH T 7
ELEV. (MSL.) 300 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
FILL
Loose, dry, pale yellowish brown, Silty, fine to
medium SAND
COLLUVIUM
Loose, damp, dark yellowish brown to moderate
brown, Silty, fine to medium SAND
Becomes moist to wet
SANTIAGO FORMATION
_. Medium dense, moist to wet very pale orange __
\ Silty, fine to medium SAND, massive /
TRENCH TERMINATED AT 11 FEET
z /-*
°o '
L_ "^ I
««"
||| ^"^ ^^
fc> ||| ^-J
Q. ^
_
>_
t—/^
fn •
UJ(J
° •
CZ^Ct
s^
UJ"^rv
2$
g"
O
- Figure A-7, Log of Trench T 7 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
S ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE f. ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 2 -
- 4 -1
SAMPLE
NO.
T8-1
;_LITHOLOG~.1 "' / .
"-i. ] -
v--1 1
-'}]'.'
li .
•i-!---
1 1 -. .• i'i- 1i
1 1&.
1 . _- 1w -1
"1
a:
UJ
GROUNDUA1SOIL
CLASS
(USCS)
SM
SM
TRENCH T 8
ELEV. (MSL.) 302 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOBL/COLLUVIUM
Very loose, (caving) saturated, dark yellowish
brown, Silty, fine to coarse SAND. Trench caving,
cannot enter, flowing water
-Heavy seepage at lower contact
LINDAVISTA FORMATION
Loose to medium dense, moist, mottled moderate
brown, grayish orange and gray, Silty, fine to
coarse SAND with rounded fine gravel
TRENCH TERMINATED AT 5 FEET
DID NOT ENTER CAVING TRENCH
z /^ENETRATIORESISTANCEBLOWS/FT.Q- ^
_
—
_
^.
^
Q
^MOISTUREONTENT (.'/,o
m Figure A-8, Log of Trench T 8 PLR3
SAMPLE SYMBOLS IH... SAMPLING UNSUCCESSFUL
H ... DISTURBED OR BAG SAMPLE
C... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
B ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
SAMPLE
NO.
1
T9-1 LITHOLOGY• i i -
"']• ' "
It--1 u
II ]•".-Jlrt -T9-2 [Ijljj
11
1 GROUNDWATERSOIL
CLASS
CUSCS)
SM
SM
TRENCH T 9
ELEV. (MSL.) 324 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOEL/COLLUVIUM
Loose, dry, moderate yellowish brown, Silty, fine
to coarse SAND
LINDAVISTA FORMATION
Loose, dry to damp, light brown, Silty, fine to
coarse SAND, trace of rounded fine gravel.
Becomes medium dense below 3 feet
TRENCH TERMINATED AT 4 FEET ENETRATIONRESISTANCEBLOWS/FT.)0. ^
_RY DENSITY(P.C.F.)Q
120.8 MOISTUREONTENT Mo
6.3
- Figure A-9, Log of Trench T 9 PLR3
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST I ... DRIVE SAMPLE (UNDISTURBED)
H ... DISTURBED OR BAG SAMPLE G ... CHUNK SAMPLE JL ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 4 -
~ —
SAMPLE
NO.
,_LITHOLOGV!"i1 --1 1.:-i- ----j.i-
••]'•!"-"
v -: |•" r]•- 1
{•*"-:!t.
ceLU
<n
z
occCO
SOIL
CLASS
(USCS)
SM
SM
TRENCH T10
ELEV. (MSL.) 338 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOEL/COLLUVIUM
Loose, dry, moderate yellowish brown, Silty, fine
to coarse SAND
LINDAVISTA FORMATION
Medium dense, dry to damp, light brown, mottled
black, Silty, fine to coarse SAND, trace of rounded
fine gravel
TRENCH TERMINATED AT 6 FEET
"2. s*.ENETRATIORESISTANCEBLOWS/FT.Q."-'W
_
_
_
~
^_
t—^
gul
go
Q
^MOISTUREONTENT <•/.u
Figure A-10, Log of Trench T 10 PLR3
SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL
... DISTURBED OR BAG SAMPLE
C... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
K ... CHUNK SAMPLE f. ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 2 -
- 4 -
SAMPLE
NO.
Tll-1 5"=
1
1 LITHOLOGY::J:[:•i t:.j J-.
;[{".
T"-2 lit -
T""3 1|:-NDWATERaa
SOIL
CLASS
(USCS)
SM
SM
TRENCH Til
ELEV. (MSL.) 344 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Loose, damp to wet, moderate yellowish brown,
Silty, fine to coarse SAND, rootlets, porous
LJNDAVISTA FORMATION
Medium dense, damp, light brown, mottled gray,
Silty, fine to coarse SAND
TRENCH TERMINATED AT 5 FEET ENETRATIONRESISTANCEBLOWS/FT.)Q_«-^-'
_
-
,RY DENSITY(P.C.F.)a
118.6 MOISTUREONTENT (X)a
9.4
- Figure A-ll, Log of Trench T 11 PLR3
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST
H ... DISTURBED OR BAG SAMPLE K ... CHUNK SAMPLE
•... DRIVE SAMPLE (UNDISTURBED)
f. ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 2 -
-
- 4 -
-
- 6 -
SAMPLE
NO.LITHOL06YV.-1-
T -'j -T. -
-\\,_
-V}-
V-ji..
'I-/'-
V
J -i. -- 1 j.
-|.i'-'JNDWATERa
C3
SOIL
CLASS
(USCS)
SM
SM
TRENCH T 12
ELEV. (MSL.) 349 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
FELL
Loose to medium dense, damp, moderate brown,
Silty, fine to coarse SAND
LINDAVISTA FORMATION
Medium dense, damp, light and moderate brown,
Silty, fine to coarse SAND
TRENCH TERMINATED AT 6.5 FEET ENETRATIONRESISTANCEBLOWS/FT.)Q- ^
„
-RY DENSITY(P.C.F.)a MOISTUREONTENT (X.)u
Figure A-12, Log of Trench T 12 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
H ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE 3P ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
- 2 -
SAMPLE
NO.LITHOLOGY|ri ^- j.•-M'-"
_}t..
\'\GROUNDWATERSOIL
CLASS
(USCS)
SM
SM
TRENCH T13
ELEV. (MSL.) 365 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
FILL
Loose to medium dense, damp, light and moderate
brown, Silty, fine to coarse SAND
LJNDAVISTA FORMATION
__ Medium dense, damp, light and moderate brown,
\ Silty, fine to coarse SAND /
TRENCH TERMINATED AT 4 FEET ENETRATIONRESISTANCEBLOWS/FT.)Q.1*-^
_RY DENSITY(P.C.F.)Q MOISTUREONTENT 00CJ
- Figure A-13, Log of Trench T 13 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C . . . STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
- 2 -
SAMPLE
NO.
T14-1 THOL06YH
I}'
'-I-!--
T-!'
:'! ('
rv
JNDUATE0ceCD
SOIL
CLASS
(USCS)
SM
SM
TRENCH T 14
ELEV. (MSL.) 354 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Loose, damp, moderate brown, Silty, fine to
medium SAND, rootlets
LJNDAVISTA FORMATION
Medium dense, damp, light brown, Silty, fine to
coarse SAND
TRENCH TERMINATED AT 3 FEET 'RATIONSTANCEIS/FT.)^co°
Lu^^
-
-
Ei-gu!
£cJo .
>°-£~Q
/^
US
= 1-cnf?i
H^ot
^0CJ
Figure A-14, Log of Trench T 14 PLR3
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL C . . . STANDARD PENETRATION TEST
H ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE
... DRIVE SAMPLE (UNDISTURBED)
. . . WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
.
- 2 -
SAMPLE
NO.
T15-1 I
J LITHOL06Y• i -
-.1-,
•'1 .
- \
"• - --t 1:k!.•i- -i-*GROUNDUATER |SOIL
CLASS
(USCS)
SM
5M/ML
TRENCH T 15
ELEV. (MSL.) 340 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSODL/COLLUVIUM
Loose, wet (saturated) moderate brown to dark
yellowish brown, Silty, fine to coarse SAND,
rootlets
-Seepage at contact
LINDAVISTA FORMATION
Loose to medium dense, wet to damp, mottled dark
\ yellowish orange, gray, Silty, fine to medium /
\ SAND/Sandy SILT /
TRENCH TERMINATED AT 4 FEET PENETRATIONRESISTANCE(BLOWS/FT.)_
-DRY DENSITY(P.C.F.)MOISTURECONTENT (.'/.)Figure A-15, Log of Trench T 15 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE K ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
.
- 2 -
- 4 -
-
SAMPLE
NO.
sT16-1
X
X
3C')LITHOLO.1
-;
h't .
'i •- 1
.-!•
'
K
'.
'
-
'.
QLLU1—GROUNDUASOIL
CLASS
(USCS)
SM
SM
SM/ML
TRENCH T 16
ELEV. (MSL.) 320 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVTUM
Loose, wet, dark yellowish brown to olive black,
Silty, fine to coarse SAND, abundant organics
ALLUVIUM
Loose, (caving) wet/saturated, moderate yellowish
brown, Silty,fine to coarse SAND. Trench caving,
cannot enter, flowing water
-Heavy seepage at contact
LINDAVISTA FORMATION
Loose to medium dense, mottled dark yellowish
\ orange, gray, Silty, fine to medium SAND/Sandy /
\ SILT /
TRENCH TERMINATED AT 7 FEET
DID NOT ENTER CAVING TRENCH
Zi.i~i— i LU .ENETRATK?ESISTANCBLOUS/FTQ. ^
_
5_
Id
Q
^MOISTUREONTENT C0
• Figure A-16, Log of Trench T 16 PLR3
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED)
§§ ... DISTURBED OR BAG SAMPLE E ... CHUNK SAMPLE T. ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
SAMPLE
NO.
CDo
LITHOL•-!T-'
r-
•r<-"1 ' •:-1 J.'1 1 -J" '
C£u
<T
c
Q
SOIL
CLASS
(USCS)
SM
SM
TRENCH T 17
ELEV. (MSL.) 314 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Loose, moist, dark yellowish brown and olive
black, Silty, fine to coarse SAND, abundant
organics, highly odiferous
LJNDAVISTA FORMATION
Loose, wet, light brown, Silty, fine to coarse
SAND
-Becomes medium dense at 4 feet
TRENCH TERMINATED AT 4 FEET
ZLU~ENETRAT]JESISTANBLOWS/F1OL ^
_
Ijj
Q
~
III *^MOISTURONTENT <u
. Figure A-17, Log of Trench T 17 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
H ... DISTURBED OR BAG SAMPLE K ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
SAMPLE
NO.
T18-1 i
CDa
LITHOL"i !•'"•!•!1 \- 1 J.
A\'~-'1 rtn
{£U
<r
GROUNDUSOIL
CLASS
(USCS)
SM
SM
TRENCH T 18
ELEV. (MSL.) 324 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Loose, dry, moderate to dark yellowish brown,
Silty, fine to medium SAND, rootlets
LINDAVISTA FORMATION
Medium dense, moist, light brown, Silty, fine to
coarse SAND with fine rounded gravel /
TRENCH TERMINATED AT 3 FEET
zui~i» CJ i
ENETRAT]?ESISTANBLOUS/Fltt. s^'
_
^d
o
118.2
~
LU i
MOISTURONTENT <o
7.9
Figure A-18, Log of Trench T 18 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED)
H ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE T. ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 06313-12-01
DEPTH
IN
FEET
_
*•>z
..
- 4 -
SAMPLE
NO.LITHOLOGYT--
•j I
:i|--
A\''-~\ • -i•i.j--
jl:GROUNDWATER ISOIL
CLASS
(USCS)
SM
SM
TRENCH T 19
ELEV. (MSL.) 297 DATE COMPLETED 5/17/99
EQUIPMENT JD 555
MATERIAL DESCRIPTION
TOPSOIL/COLLUVIUM
Loose, dry, pale yellowish brown, Silty, fine to
medium SAND
SANTIAGO FORMATION
Medium dense, dry to moist, light brown, fine to
coarse Silty SAND
TRENCH TERMINATED AT 5 FEET ENETRATIONRESISTANCEBLOWS/FT.)Q."-^
_
_RY DENSITY(P.C.F.)a MOISTUREONTENT (*)a
- Figure A-19, Log of Trench T 19 PLR3
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST
H ... DISTURBED OR BAG SAMPLE B . . . CHUNK SAMPLE
... DRIVE SAMPLE (UNDISTURBED)
... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
c
I
I
I
I
£
E
I
I
I
1
E
I
I
I
I
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I
I
APPENDtX
APPENDIX B
LABORATORY TESTING
Laboratory tests were performed in accordance with generally accepted test methods of the
American Society for Testing and Materials (ASTM) or other suggested procedures. Selected
samples were tested for their in-place density and moisture content, direct shear strength, expansion,
and maximum dry density and optimum moisture content. The results of these tests are summarized
on Tables B-I through B-III and the in-place dry density and moisture content results are indicated
on the exploratory trench logs.
TABLE B-I
SUMMARY OF LABORATORY MAXIMUM DRY DENSITY
AND OPTIMUM MOISTURE CONTENT TEST RESULTS
ASTM D 1557-91
Sample
No.
T3-2
Tll-2
Description
Pale Yellowish, Brown, Clayey, fine to
medium SAND
Light Brown Silty, fine to coarse SAND
Maximum Dry
Density (pcf)
119.5
127.0
Optimum Moisture
Content (% dry wt.)
12.0
10.8
TABLE B-ll
SUMMARY OF LABORATORY DIRECT SHEAR TEST RESULTS*
Sample No.
T3-2
Dry Density
(pcf)
107.5
Moisture Content
(%)
12.2
Unit Cohesion
(psf)
390
Angle of Shear
Resistance (degrees)
28
"Soil sample was remolded to 90 percent relative density at near optimum moisture content.
TABLE B-III
SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS
Sample
No.
T15-1
Moisture Content
Before Test (%)
8.0
After Test (%)
23.7
Dry Density
(pcf)
117.5
Expansion
Index
2
Classification
Very Low
Project No. 06313-12-01 June 10, 1999
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C
C
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APPENDIX
APPENDIX C
RECOMMENDED GRADING SPECIFICATIONS
FOR
POINSETTIA LANE ("REACH 3")
CARLSBAD, CALIFORNIA
PROJECT NO. 06313-12-01
RECOMMENDED GRADING SPECIFICATIONS
1. GENERAL
1.1. These Recommended Grading Specifications shall be used in conjunction with the
Geotechnical Report for the project prepared by Geocon Incorporated. The recom-
mendations contained in the text of the Geotechnical Report are a part of the earthwork and
grading specifications and shall supersede the provisions contained hereinafter in the case
of conflict.
1.2. Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be
employed for the purpose of observing earthwork procedures and testing the fills for
substantial conformance with the recommendations of the Geotechnical Report and these
specifications. It will be necessary that the Consultant provide adequate testing and
observation services so that he may determine that, in his opinion, the work was performed
in substantial conformance with these specifications. It shall be the responsibility of the
Contractor to assist the Consultant and keep him apprised of work schedules and changes
so that personnel may be scheduled accordingly.
1.3. It shall be the sole responsibility of the Contractor to provide adequate equipment and
methods to accomplish the work in accordance with applicable grading codes or agency
ordinances, these specifications and the approved grading plans. If, in the opinion of the
Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture
condition, inadequate compaction, adverse weather, and so forth, result in a quality of work
not in conformance with these specifications, the Consultant will be empowered to reject
the work and recommend to the Owner that construction be stopped until the unacceptable
conditions are corrected.
2. DEFINITIONS
2.1. Owner shall refer to the owner of the property or the entity on whose behalf the grading
work is being performed and who has contracted with the Contractor to have grading
performed.
2.2. Contractor shall refer to the Contractor performing the site grading work.
2.3. Civil Engineer or Engineer of Work shall refer to the California licensed Civil Engineer
or consulting firm responsible for preparation of the grading plans, surveying and verifying
as-graded topography.
GI rev. 8/98
2.4. Consultant shall refer to the soil engineering and engineering geology consulting firm
retained to provide geotechnical services for the project.
2.5. Soil Engineer shall refer to a California licensed Civil Engineer retained by the Owner,
who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be
responsible for having qualified representatives on-site to observe and test the Contractor's
work for conformance with these specifications.
2.6. Engineering Geologist shall refer to a California licensed Engineering Geologist retained
by the Owner to provide geologic observations and recommendations during the site
grading.
2.7. Geotechnical Report shall refer to a soil report (including all addenda) which may include
a geologic reconnaissance or geologic investigation that was prepared specifically for the
development of the project for which these Recommended Grading Specifications are
intended to apply.
3. MATERIALS
3.1. Materials for compacted fill shall consist of any soil excavated from the cut areas or
imported to the site that, in the opinion of the Consultant, is suitable for use in construction
of fills. In general, fill materials can be classified as soil fills, soil-rock fills or rock fills, as
defined below.
3.1.1. Soil fills are defined as fills containing no rocks or hard lumps greater than 12
inches in maximum dimension and containing at least 40 percent by weight of
material smaller than 3/4 inch in size.
3.1.2. Soil-rock fills are defined as fills containing no rocks or hard lumps larger than 4
feet in maximum dimension and containing a sufficient matrix of soil fill to allow
for proper compaction of soil fill around the rock fragments or hard lumps as
specified in Paragraph 6.2. Oversize rock is defined as material greater than 12
inches.
3.1.3. Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet
in maximum dimension and containing little or no fines. Fines are defined as
material smaller than 3/4 inch in maximum dimension. The quantity of fines shall
be less than approximately 20 percent of the rock fill quantity.
' GI rev. 8/98
3.2. Material of a perishable, spongy, or otherwise unsuitable nature as determined by the
Consultant shall not be used in fills.
3.3. Materials used for fill, either imported or on-site, shall not contain hazardous materials as
defined by the California Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9
and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shall
not be responsible for the identification or analysis of the potential presence of hazardous
materials. However, if observations, odors or soil discoloration cause Consultant to
suspect the presence of hazardous materials, the Consultant may request from the Owner
the termination of grading operations within the affected area. Prior to resuming grading
operations, the Owner shall provide a written report to the Consultant indicating that the
suspected materials are not hazardous as defined by applicable laws and regulations.
3.4. The outer 15 feet of soil-rock fill slopes, measured horizontally, should be composed of
properly compacted soil fill materials approved by the Consultant. Rock fill may extend to
the slope face, provided that the slope is not steeper than 2:1 (horizontal:vertical) and a soil
layer no thicker than 12 inches is track-walked onto the face for landscaping purposes.
This procedure may be utilized, provided it is acceptable to the governing agency, Owner
and Consultant.
3.5. Representative samples of soil materials to be used for fill shall be tested in the laboratory
by the Consultant to determine the maximum density, optimum moisture content, and,
where appropriate, shear strength, expansion, and gradation characteristics of the soil.
3.6. During grading, soil or groundwater conditions other than those identified in the
Geotechnical Report may be encountered by the Contractor. The Consultant shall be
notified immediately to evaluate the significance of the unanticipated condition
4. CLEARING AND PREPARING AREAS TO BE FILLED
4.1. Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of
complete removal above the ground surface of trees, stumps, brush, vegetation, man-made
structures and similar debris. Grubbing shall consist of removal of stumps, roots, buried
logs and other unsuitable material and shall be performed in areas to be graded. Roots and
other projections exceeding 1-1/2 inches in diameter shall be removed to a depth of 3 feet
below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to
provide suitable fill materials.
GI rev. 8/98
4.2. Any asphalt pavement material removed during clearing operations should be properly
disposed at an approved off-site facility. Concrete fragments which are free of reinforcing
steel may be placed in fills, provided they are placed in accordance with Section 6.2 or 6.3
of this document.
4.3. After clearing and grubbing of organic matter or other unsuitable material, loose or porous
soils shall be removed to the depth recommended in the Geotechnical Report. The depth of
removal and compaction shall be observed and approved by a representative of the
Consultant. The exposed surface shall then be plowed or scarified to a minimum depth of
6 inches and until the surface is free from uneven features that would tend to prevent
uniform compaction by the equipment to be used.
4.4. Where the slope ratio of the original ground is steeper than 6:1 (horizontahvertical), or
where recommended by the Consultant, the original ground should be benched in
accordance with the following illustration.
TYPICAL BENCHING DETAIL
Finish Grade Original Ground
Finish Slope Surface
Remove All
Unsuitable Material
As Recommended By
Soil Engineer Slope To Be Such That
Sloughing Or Sliding
Does Not Occur
See Note 1 See Note 2 -1
No Scale
DETAIL NOTES:(1) Key width "B" should be a minimum of 10 feet wide, or sufficiently wide to
permit complete coverage with the compaction equipment used. The base of the
key should be graded horizontal, or inclined slightly into the natural slope.
(2) The outside of the bottom key should be below the topsoil or unsuitable surficial
material and at least 2 feet into dense formational material. Where hard rock is
exposed in the bottom of the key, the depth and configuration of the key may be
modified as approved by the Consultant.
GI rev. 8/98
4.5. After areas to receive fill have been cleared, plowed or scarified, the surface should be
disced or bladed by the Contractor until it is uniform and free from large clods. The area
should then be moisture conditioned to achieve the proper moisture content, and compacted
as recommended in Section 6.0 of these specifications.
5. COMPACTION EQUIPMENT
5.1. Compaction of soil or soil-rock fill shall be accomplished by sheepsfoot or segmented-steel
wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of
acceptable compaction equipment. Equipment shall be of such a design that it will be
capable of compacting the soil or soil-rock fill to the specified relative compaction at the
specified moisture content.
5.2. Compaction of rock fills shall be performed in accordance with Section 6.3.
6. PLACING, SPREADING AND COMPACTION OF FILL MATERIAL
6.1. 50/7 fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with
the following recommendations:
6.1.1. Soil fill shall be placed by the Contractor in layers that, when compacted, should
generally not exceed 8 inches. Each layer shall be spread evenly and shall be
thoroughly mixed during spreading to obtain uniformity of material and moisture
in each layer. The entire fill shall be constructed as a unit in nearly level lifts.
Rock materials greater than 12 inches in maximum dimension shall be placed in
accordance with Section 6.2 or 6.3 of these specifications.
6.1.2. In general, the soil fill shall be compacted at a moisture content at or above the
optimum moisture content as determined by ASTM D1557-91.
6.1.3. When the moisture content of soil fill is below that specified by the Consultant,
water shall be added by the Contractor until the moisture content is in the range
specified.
6.1.4. When the moisture content of the soil fill is above the range specified by the
Consultant or too wet to achieve proper compaction, the soil fill shall be aerated by
the Contractor by blading/mixing, or other satisfactory methods until the moisture
content is within the range specified.
GI rev. 8/98
6.1.5. After each layer has been placed, mixed, and spread evenly, it shall be thoroughly
compacted by the Contractor to a relative compaction of at least 90 percent.
Relative compaction is defined as the ratio (expressed in percent) of the in-place
dry density of the compacted fill to the maximum laboratory dry density as
determined in accordance with ASTM D1557-91. Compaction shall be continuous
over the entire area, and compaction equipment shall make sufficient passes so that
the specified minimum relative compaction has been achieved throughout the
entire fill.
6.1.6. Soils having an Expansion Index of greater than 50 may be used in fills if placed at
least 3 feet below finish pad grade and should be compacted at a moisture content
generally 2 to 4 percent greater than the optimum moisture content for the material.
6.1.7. Properly compacted soil fill shall extend to the design surface of fill slopes. To
achieve proper compaction, it is recommended that fill slopes be over-built by at
least 3 feet and then cut to the design grade. This procedure is considered
preferable to track-walking of slopes, as described in the following paragraph.
6.1.8. As an alternative to over-building of slopes, slope faces may be back-rolled with a
heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height
intervals. Upon completion, slopes should then be track-walked with a D-8 dozer
or similar equipment, such that a dozer track covers all slope surfaces at least
twice.
6.2. Soil-rock fill, as defined in Paragraph 3.1.2, shall be placed by the Contractor in accordance
with the following recommendations:
6.2.1. Rocks larger than 12 inches but less than 4 feet in maximum dimension may be
incorporated into the compacted soil fill, but shall be limited to the area measured
15 feet minimum horizontally from the slope face and 5 feet below finish grade or
3 feet below the deepest utility, whichever is deeper.
6.2.2. Rocks or rock fragments up to 4 feet in maximum dimension may either be
individually placed or placed in windrows. Under certain conditions, rocks or rock
fragments up to 10 feet in maximum dimension may be placed using similar
methods. The acceptability of placing rock materials greater than 4 feet in
maximum dimension shall be evaluated during grading as specific cases arise and
shall be approved by the Consultant prior to placement.
GI rev. 8/98
6.2.3. For individual placement, sufficient space shall be provided between rocks to allow
for passage of compaction equipment.
6.2.4. For windrow placement, the rocks should be placed in trenches excavated in
properly compacted soil fill. Trenches should be approximately 5 feet wide and 4
feet deep in maximum dimension. The voids around and beneath rocks should be
filled with approved granular soil having a Sand Equivalent of 30 or greater and
should be compacted by flooding. Windrows may also be placed utilizing an
"open-face" method in lieu of the trench procedure, however, this method should
first be approved by the Consultant.
6.2.5. Windrows should generally be parallel to each other and may be placed either
parallel to or perpendicular to the face of the slope depending on the site
geometry. The minimum horizontal spacing for windrows shall be 12 feet
center-to-center with a 5-foot stagger or offset from lower courses to next
overlying course. The minimum vertical spacing between windrow courses shall
be 2 feet from the top of a lower windrow to the bottom of the next higher
windrow.
6.2.6. All rock placement, fill placement and flooding of approved granular soil in the
windrows must be continuously observed by the Consultant or his representative.
6.3. Rock fills, as defined in Section 3.1.3., shall be placed by the Contractor in accordance with
the following recommendations:
6.3.1. The base of the rock fill shall be placed on a sloping surface (minimum slope of 2
percent, maximum slope of 5 percent). The surface shall slope toward suitable
subdrainage outlet facilities. The rock fills shall be provided with subdrains during
construction so that a hydrostatic pressure buildup does not develop. The
subdrains shall be permanently connected to controlled drainage facilities to
control post-construction infiltration of water.
6.3.2. Rock fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock
trucks traversing previously placed lifts and dumping at the edge of the currently
placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the
rock. The rock fill shall be watered heavily during placement. Watering shall
consist of water trucks traversing in front of the current rock lift face and spraying
water continuously during rock placement. Compaction equipment with
compactive energy comparable to or greater than that of a 20-ton steel vibratory
roller or other compaction equipment providing suitable energy to achieve the
GI rev. 8/98
required compaction or deflection as recommended in Paragraph 6.3.3 shall be
utilized. The number of passes to be made will be determined as described in
Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional
rock fill lifts will be permitted over the soil fill.
6.3.3. Plate bearing tests, in accordance with ASTM Dl 196-64, may be performed in
both the compacted soil fill and in the rock fill to aid in determining the number of
passes of the compaction equipment to be performed. If performed, a minimum of
three plate bearing tests shall be performed in the properly compacted soil fill
(minimum relative compaction of 90 percent). Plate bearing tests shall then be
performed on areas of rock fill having two passes, four passes and six passes of the
compaction equipment, respectively. The number of passes required for the rock
fill shall be determined by comparing the results of the plate bearing tests for the
soil fill and the rock fill and by evaluating the deflection variation with number of
passes. The required number of passes of the compaction equipment will be
performed as necessary until the plate bearing deflections are equal to or less than
that determined for the properly compacted soil fill. In no case will the required
number of passes be less than two.
6.3.4. A representative of the Consultant shall be present during rock fill operations to
verify that the minimum number of "passes" have been obtained, that water is
being properly applied and that specified procedures are being followed. The
actual number of plate bearing tests will be determined by the Consultant during
grading. In general, at least one test should be performed for each approximately
5,000 to 10,000 cubic yards of rock fill placed.
6.3.5. Test pits shall be excavated by the Contractor so that the Consultant can state that,
in his opinion, sufficient water is present and that voids between large rocks are
properly filled with smaller rock material. In-place density testing will not be
required in the rock fills.
6.3.6. To reduce the potential for "piping" of fines into the rock fill from overlying soil
fill material, a 2-foot layer of graded filter material shall be placed above the
uppermost lift of rock fill. The need to place graded filter material below the rock
should be determined by the Consultant prior to commencing grading. The
gradation of the graded filter material will be determined at the time the rock fill is
being excavated. Materials typical of the rock fill should be submitted to the
Consultant in a timely manner, to allow design of the graded filter prior to the
commencement of rock fill placement.
GI rev. 8/98
6.3.7. All rock fill placement shall be continuously observed during placement by
representatives of the Consultant.
7. OBSERVATION AND TESTING
7.1. The Consultant shall be the Owners representative to observe and perform tests during
clearing, grubbing, filling and compaction operations. In general, no more than 2 feet in
vertical elevation of soil or soil-rock fill shall be placed without at least one field density
test being performed within that interval. In addition, a minimum of one field density test
shall be performed for every 2,000 cubic yards of soil or soil-rock fill placed and
compacted.
7.2. The Consultant shall perform random field density tests of the compacted soil or soil-rock
fill to provide a basis for expressing an opinion as to whether the fill material is compacted
as specified. Density tests shall be performed in the compacted materials below any
disturbed surface. When these tests indicate that the density of any layer of fill or portion
thereof is below that specified, the particular layer or areas represented by the test shall be
reworked until the specified density has been achieved.
7.3. During placement of rock fill, the Consultant shall verify that the minimum number of
passes have been obtained per the criteria discussed in Section 6.3.3. The Consultant shall
request the excavation of observation pits and may perform plate bearing tests on the
placed rock fills. The observation pits will be excavated to provide a basis for expressing
an opinion as to whether the rock fill is properly seated and sufficient moisture has been
applied to the material. If performed, plate bearing tests will be performed randomly on
the surface of the most-recently placed lift. Plate bearing tests will be performed to provide
a basis for expressing an opinion as to whether the rock fill is adequately seated. The
maximum deflection in the rock fill determined in Section 6.3.3 shall be less than the
maximum deflection of the properly compacted soil fill. When any of the above criteria
indicate that a layer of rock fill or any portion thereof is below that specified, the affected
layer or area shall be reworked until the rock fill has been adequately seated and sufficient
moisture applied.
7.4. A settlement monitoring program designed by the Consultant may be conducted in areas of
rock fill placement. The specific design of the monitoring program shall be as
recommended in the Conclusions and Recommendations section of the project
Geotechnical Report or in the final report of testing and observation services performed
during grading.
GI rev. 8/98
7.5. The Consultant shall observe the placement of subdrains, to verify that the drainage devices
have been placed and constructed in substantial conformance with project specifications.
7.6. Testing procedures shall conform to the following Standards as appropriate:
7.6.1. Soil and Soil-Rock Fills:
7.6.1.1. Field Density Test, ASTM D1556-82, Density of Soil In-Place By the
Sand-Cone Method.
7.6.1.2. Field Density Test, Nuclear Method, ASTM D2922-81, Density of Soil and
Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth).
7.6.1.3. Laboratory Compaction Test, ASTM D1557-91, Moisture-Density
Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound Hammer
and 18-Inch Drop.
7.6.1.4. Expansion Index Test, Uniform Building Code Standard 29-2, Expansion
Index Test.
7.6.2. Rock Fills
7.6.2.1. Field Plate Bearing Test, ASTM Dl 196-64 (Reapproved 1977) Standard
Method for Nonrepresentative Static Plate Load Tests of Soils and Flexible
Pavement Components, For Use in Evaluation and Design of Airport and
Highway Pavements.
8. PROTECTION OF WORK
8.1. During construction, the Contractor shall properly grade all excavated surfaces to provide
positive drainage and prevent ponding of water. Drainage of surface water shall be
controlled to avoid damage to adjoining properties or to finished work on the site. The
Contractor shall take remedial measures to prevent erosion of freshly graded areas until
such time as permanent drainage and erosion control features have been installed. Areas
subjected to erosion or sedimentation shall be properly prepared in accordance with the
Specifications prior to placing additional fill or structures.
8.2. After completion of grading as observed and tested by the Consultant, no further
excavation or filling shall be conducted except in conjunction with the services of the
Consultant.
GI rev. 8/98
9. CERTIFICATIONS AND FINAL REPORTS
9.1. Upon completion of the work, Contractor shall furnish Owner a certification by the Civil
Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of
elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot
horizontally of the positions shown on the grading plans. After installation of a section of
subdrain, the project Civil Engineer should survey its location and prepare an as-built plan
of the subdrain location. The project Civil Engineer should verify the proper outlet for the
subdrains and the Contractor should ensure that the drain system is free of obstructions.
9.2. The Owner is responsible for furnishing a final as-graded soil and geologic report
satisfactory to the appropriate governing or accepting agencies. The as-graded report
should be prepared and signed by a California licensed Civil Engineer experienced in
geotechnical engineering and by a California Certified Engineering Geologist, indicating
that the geotechnical aspects of the grading were performed in substantial conformance
with the Specifications or approved changes to the Specifications.
GI rev. 8/98